Add pipe-selection copy mode command

* refs/remotes/tmux-openbsd/master:
  Add rounded borders option for panes like popups.

.github/workflows/lock.yml

@@ -17,8 +17,9 @@ jobs:
   action:
     runs-on: ubuntu-latest
     if: github.repository == 'tmux/tmux'
+    timeout-minutes: 10
     steps:
-      - uses: dessant/lock-threads@v6
+      - uses: dessant/lock-threads@89ae32b08ed1a541efecbab17912962a5e38981c # v6
         with:
           github-token: ${{ github.token }}
           issue-inactive-days: '30'

.github/workflows/regress.yml

@@ -17,7 +17,7 @@ jobs:
     name: ${{ matrix.name }}
     runs-on: ${{ matrix.runner }}
     if: github.repository == 'tmux/tmux'
-    timeout-minutes: 45
+    timeout-minutes: 300
 
     strategy:
       fail-fast: false
@@ -38,7 +38,9 @@ jobs:
 
     steps:
       - name: checkout
-        uses: actions/checkout@v4
+        uses: actions/checkout@11d5960a326750d5838078e36cf38b85af677262 # v4
+        with:
+          persist-credentials: false
 
       - name: dependencies
         if: runner.os == 'Linux'
@@ -81,7 +83,7 @@ jobs:
 
       - name: logs
         if: failure()
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4
         with:
           name: regress-logs-${{ matrix.name }}
           path: regress/logs/*.log

CHANGES

@@ -9,7 +9,12 @@ CHANGES FROM 3.7c TO 3.8
 
   - modal panes may be created with new-pane -O; a window can have one modal
     pane and it prevents interaction with the other panes while it is active.
-    A modal pane is now used for the editor in buffer mode;
+    -C closes the pane when the mouse is clicked outside it and -K sends all
+    keys, including the prefix key, to the pane. A modal pane is now used for
+    the editor in buffer mode;
+
+  - new-pane -A creates a floating pane which remains above a zoomed pane;
+    modal panes do this by default;
 
   - move-pane and resize-pane can now move and resize floating panes, including
     mouse dragging;
@@ -24,10 +29,15 @@ CHANGES FROM 3.7c TO 3.8
     -k for choose commands kills the pane when the mode exits, which is useful
     for modes in floating panes;
 
-  - pane-border-status has top-floating and bottom-floating, and there are new
-    default bindings under C-b g for common move and resize operations;
+  - command-prompt -P opens a prompt inside a pane rather than on the status
+    line;
 
-  - floating panes are unzoomed before creation to avoid a crash.
+  - pane-border-status has top-floating and bottom-floating, and there are new
+    default bindings under C-b g for common move and resize operations.
+
+* Layout strings now use a JSON subset format which includes floating panes.
+  The old format is still accepted; control mode clients receive old layouts
+  unless they set the new-layouts flag.
 
 * Add support for themes and improve default colours:
 
@@ -74,7 +84,7 @@ CHANGES FROM 3.7c TO 3.8
 
   - new hooks to cover areas including client create and destroy, pane
     activity, pane mode and prompt changes, pane movement and resizing, session
-    group changes and window creation, close and zoom;
+    group changes and window creation, close, swap and zoom;
 
   - OSC 133 escape sequences now trigger events: pane-command-started,
     pane-command-finished and pane-shell-prompt.
@@ -87,10 +97,23 @@ CHANGES FROM 3.7c TO 3.8
   while scrolling or while hovered and disappears after pane-scrollbars-timeout
   (Michael Grant).
 
-* Extend the fill-character option so both inside and outside the window can be
-  changed.
+* Add a clear-on-attach server option. When disabled, tmux does not enter the
+  alternate screen on attach and instead scrolls the existing terminal content
+  into the scrollback buffer so it remains accessible (issue 5508).
 
-* Change set-option and set-hooks to use formats and add a -F flag to each.
+* Copy mode can now automatically refresh as pane content changes with the
+  refresh-on, refresh-off and refresh-toggle commands. Automatic refresh is off
+  by default; refresh-now refreshes once and is bound to r. These replace
+  refresh-from-pane (issue 5165).
+
+* Extend the fill-character option so both inside and outside the window can be
+  changed, with a new default for unused areas inside the window.
+
+* Change show-options and show-hooks to use formats and add a -F flag to each.
+
+* Allow individual terminal features to be disabled by adding @ to their names
+  in terminal-features, and add a utf8 feature for terminals which support
+  UTF-8 output.
 
 * Add a #{A/count:frames} modifier to show a series of frames as an animation
   in the status line (issue 5412 from Fernando Daciuk).
@@ -105,6 +128,12 @@ CHANGES FROM 3.7c TO 3.8
 * Add new-window -E, respawn-pane -E and respawn-window -E as more convenient
   methods to create an empty pane (rather than using '' for the command).
 
+* Add capture-pane -I to include the time each line entered history.
+
+* Various memory leak fixes from Heon Jeong.
+
+* Add a default C-b T binding to change the current pane title.
+
 * Menus now belong to the window, so appear on all clients.
 
 * Dragging over an existing copy mode selection now adjusts it (Michael Grant).
@@ -118,6 +147,13 @@ CHANGES FROM 3.7c TO 3.8
 * Copy mode no longer exits at the bottom while a selection is in progress
   (issue 5349).
 
+* Add copy-mode-current-line-style to set the style of the line containing the
+  cursor in copy mode (issue 5391).
+
+* Copy mode word commands now recognise all Unicode whitespace characters; a
+  space in word-separators matches any Unicode whitespace character (issue
+  5562).
+
 * Add style attributes for dimming colours (dim=) and for hyperlinks (link= and
   nolink) (issues 4842 and 4280 from Moritz Angermann).
 
@@ -128,7 +164,9 @@ CHANGES FROM 3.7c TO 3.8
 
 * Add or improve format variables including client_colours,
   pane_start_command_list, window_manual_width, window_manual_height,
-  pane_last_output_time, pane_modal_flag and window_modal_pane.
+  pane_last_output_time, pane_modal_flag, window_modal_pane, pane_private_modes,
+  pane_output_generation, history_added, history_collected, history_generation,
+  hook_fire_count and hook_fire_time.
 
 * Add additional pane sort orders, and a z sort order for choose-tree so
   floating panes can be sorted by z-index.
@@ -140,12 +178,18 @@ CHANGES FROM 3.7c TO 3.8
 
 * The mouse option now defaults to on.
 
+* The active-pane client flag has been removed.
+
 * Fix send-keys -K so keys are inserted in the correct place in the input
   queue, like keys from key bindings (issue 3476).
 
 * Fix control mode clients hanging on exit if pty data was still queued (Ben
   Maurer, issue 5356), and avoid sending notifications to clients which are
-  already exiting (Ben Maurer, issue 5357).
+  already exiting (Ben Maurer, issue 5357). Queue notifications so they are not
+  sent inside %begin/%end (issue 5458), do not let a stuck client prevent the
+  server from exiting (issue 5444), and reset control mode offsets when a pane
+  is respawned (issue 5498). Bound buffered command replies so a control mode
+  client that stops reading cannot consume unlimited memory (issue 5565).
 
 * Fix grouped sessions sometimes being left as unusable command targets while
   they are being killed (Bryce Miller, issue 5180).

IMAGE-REDRAW-PLAN.md

@@ -1,715 +0,0 @@
-# Image Redraw and Damage Plan
-
-## Purpose
-
-Make image redraws correct and efficient for tiled panes, floating panes,
-scrolling, copy-mode selection, pane borders, pane status lines, scrollbars,
-and clients using different output protocols.
-
-The intended model is retained: the visible screen is a scene of horizontal
-cell spans. A change damages cell-aligned regions, and the compositor redraws
-only scene spans intersecting those regions.
-
-Synchronized output may hide unavoidable intermediate terminal updates, but
-it must not be required for correctness.
-
-## Current state and recovery point
-
-The last clean, pushed commit on `4902-image-support` is:
-
-```
-ec9859b1 sixel: preserve image aspect across client geometries
-```
-
-That commit already contains the important persistent model:
-
-- sparse image placements represented by spans attached to grid lines;
-- input-protocol semantics and placement ordering;
-- source coordinates for cropping placement spans;
-- movement, copying, duplication, and removal of image spans with grid data;
-- per-client output backends for Kitty, SIXEL, and fallback rendering; and
-- cached image/rendering data.
-
-The current uncommitted changes touch eight files and mix several attempted
-optimizations. They are known to damage SIXEL in Mintty and cause unnecessary
-redraws with floating panes. Do not commit them as the solution.
-
-Before discarding them, save one patch outside the branch for reference:
-
-```
-git diff -- image.c regress/image-support.sh screen-redraw.c screen-write.c \
-    server-client.c tmux.h tty.c window-copy.c \
-    > /tmp/4902-image-redraw-experiment.patch
-```
-
-Then restore those tracked files to `ec9859b1` before beginning the new work.
-Do this only after the user explicitly approves the rollback.
-
-### Ideas worth retaining, but reimplementing separately
-
-- Redraw damage should be restricted to scene-visible spans.
-- Image-related selection tests are useful.
-- Floating-pane and pane-status regression scenarios are useful.
-- Window chrome must be emitted after pane image/text composition whenever
-  the same damaged region contains both.
-- A placement's complete canvas may need to be represented even where its
-  pixels are transparent; visibility and alpha must then be tested while
-  compositing rather than by losing the placement geometry.
-- Native scrolling should be selected according to the affected region and
-  backend behaviour.
-
-### Changes not worth retaining in their present form
-
-- Promoting an obscured-pane update to `PANE_REDRAW` and then sometimes to
-  `CLIENT_REDRAWWINDOW`.
-- Repairing images directly from individual `tty_cmd_*` text functions.
-- Separate ad-hoc redraw paths for images, selection, scrollbars, borders,
-  and floating panes.
-- The current `TTY_CTX_IMAGE_SCROLL`, `TTY_CTX_PANE_FULL_WIDTH`, and
-  `CLIENT_REDRAWSCROLLBARS` plumbing as a combined patch.
-- Assuming an unchanged pane-status string does not need physical redraw
-  after some other drawing operation has covered its cells.
-
-## Required invariants
-
-These rules should be written down in code comments and enforced throughout
-the implementation.
-
-1. **Input determines semantics.** Whether text removes an image layer, lies
-   above it, or lies below it is determined by the protocol received from the
-   application. It must not depend on whether the outer client uses Kitty,
-   SIXEL, or fallback output.
-
-2. **Output backends encode a scene.** An output backend may choose different
-   escape sequences, caches, or cropping, but it must render the same logical
-   result.
-
-3. **One compositor owns repair.** No output path may independently erase and
-   reconstruct image cells without going through the same scene ordering.
-
-4. **Damage is regional.** Ordinary content changes do not become pane-wide
-   or window-wide redraws. Full redraw remains appropriate for attachment,
-   resize, geometry changes, terminal reset, or invalid scene geometry.
-
-5. **Damage uses cell coordinates.** Pixel offsets are handled when an image
-   backend maps the damaged cells to a source-pixel crop.
-
-6. **Logical state changes before physical output.** Grid text and image spans
-   are moved, removed, or inserted first. Rendering then reads the completed
-   logical state.
-
-7. **Chrome is part of composition.** Pane borders, pane status lines,
-   scrollbars, menus, and floating panes must not be repaired independently in
-   an order that allows image output to cover them afterward.
-
-8. **No-image behaviour remains unchanged.** When a damaged region does not
-   intersect image data or graphical overlays, existing fast text output and
-   native scrolling should remain available.
-
-## Established image semantics
-
-The image semantics present at the `ec9859b1` recovery point are a
-compatibility requirement. They resulted from the review discussion in PR
-#5445, particularly the temporal-versus-positional model described in
-[Theory and Practice of Sprixels](https://nick-black.com/dankwiki/index.php?title=Theory_and_Practice_of_Sprixels#Transparency_and_z-ordering),
-and were accepted after commit `a4abd616`, which added the corresponding
-manual visual checks.
-
-- SIXEL input is temporal. Transparent pixels preserve what existed when the
-  SIXEL was emitted. A later text write annihilates the affected SIXEL cells;
-  the SIXEL does not remain logically behind that text.
-- Kitty input is positional. Negative-z placements remain below the text plane;
-  nonnegative placements remain above it. Text writes do not convert or remove
-  Kitty placements merely because the output client uses SIXEL.
-- Overlapping placements remain separate ordered layers. Transparent pixels in
-  an upper placement reveal retained lower placements or text.
-- Input protocol, z-index, and placement order determine the logical scene. The
-  attached client's output protocol only determines how that scene is encoded.
-- Redraw, damage, scrolling, copy mode, and backend conversion must preserve
-  these rules exactly.
-
-The manual checks introduced by `a4abd616` and the corresponding regression
-cases are semantic compatibility tests, not merely visual diagnostics.
-
-## Coordinate spaces
-
-Keep conversions explicit. Do not pass ambiguous `x` and `y` values between
-layers.
-
-- **Grid coordinates:** include history and belong to a pane's `struct grid`.
-- **Pane coordinates:** visible cells inside a pane.
-- **Window coordinates:** include pane offsets and floating-pane positions.
-- **Client scene coordinates:** window coordinates clipped by the client's
-  viewport (`ox`, `oy`, `sx`, and `sy`).
-- **Terminal coordinates:** include the client status-line offset and any
-  terminal viewport offset.
-- **Image source coordinates:** identify cell rows/columns within a placement;
-  the backend maps these to source pixels using terminal cell geometry and
-  placement pixel offsets.
-
-Store damage in window coordinates. Translate and clip it separately for each
-client when drawing, because clients may have different viewports, status-line
-positions, cell geometries, and output backends.
-
-## Compartmentalization
-
-Keep image implementation details in the existing image files. The rest of
-tmux should know only that some scene cells require image-aware composition.
-
-### `image.c`
-
-Own all protocol-independent image state and composition policy:
-
-- placements, spans, input protocol, z-index, serial ordering, and alpha;
-- applying input semantics when text overwrites image cells;
-- testing whether a grid rectangle intersects image placements;
-- mapping a damaged cell rectangle to ordered image fragments;
-- deciding which logical image layers are below or above the text plane;
-- generic backend dispatch; and
-- public image helpers used by the redraw subsystem.
-
-### `image-sixel.c`
-
-Own only SIXEL-specific output details:
-
-- cached quantized/indexed representations;
-- mapping cell crops to pixel and six-pixel-band crops;
-- emitting SIXEL fragments;
-- alpha and palette encoding; and
-- backend-specific reset, erase, and scrolling capabilities.
-
-### `image-kitty.c`
-
-Own only Kitty-specific output details:
-
-- client-side transmission and placement caches;
-- placement creation, clipping, movement, and deletion;
-- Kitty IDs and geometry; and
-- backend-specific reset and scrolling behaviour.
-
-### Other tmux files
-
-- `screen-redraw.c` owns scene construction, damage clipping, and the ordering
-  of pane content versus window chrome. It calls generic `image.c` helpers and
-  contains no Kitty or SIXEL protocol logic.
-- `screen-write.c` updates logical grid state and reports pane/window damage.
-  It must not render image fragments or select an output backend.
-- `tty.c` owns terminal text and scrolling primitives. It receives an already
-  selected native-scroll operation; it must not reconstruct image layers or
-  call image repair after individual characters.
-- `server-client.c` schedules and drains per-client damage. It must not inspect
-  image placements or output protocols.
-- `window-copy.c` reports copy-mode damage and copies logical image state using
-  generic image helpers; it must not render images itself.
-- `tmux.h` exposes only the minimum generic structures and function prototypes
-  required across those boundaries.
-
-Prefer one generic call from `screen-redraw.c` into `image.c` over `ENABLE_IMAGES`
-branches scattered through tty commands. A build without image support should
-retain the existing redraw path with minimal conditional code.
-
-## Damage representation
-
-Add a small regional damage abstraction owned by the redraw subsystem. Do not
-add per-cell queues or enlarge `struct grid_cell`.
-
-A damage entry needs:
-
-```
-x, y, sx, sy       window-cell rectangle
-reason             content, scroll exposure, pane move, chrome, and so on
-```
-
-The exact names should follow tmux style. A short list or dynamic array per
-client is sufficient. When a new rectangle is added:
-
-- clip it to the window;
-- discard empty rectangles;
-- merge overlapping or directly adjacent rectangles where that does not make
-  the result substantially larger;
-- cap the list at a modest number; above the cap, replace it with their union;
-- promote to a full redraw only if geometry is invalid or the union covers
-  most of the client scene.
-
-A shared window damage list must not be cleared after the first client draws.
-Either append translated window rectangles to every affected client, or give
-damage events monotonically increasing sequence numbers so each client can
-consume them independently. The simpler initial implementation is to append
-window-coordinate rectangles to each client currently displaying the window.
-
-Suggested public operations are conceptually:
-
-```
-redraw_damage_window(window, x, y, sx, sy, reason)
-redraw_damage_pane(window_pane, x, y, sx, sy, reason)
-redraw_damage_client(client, x, y, sx, sy, reason)
-```
-
-Do not expose image-backend details through these calls.
-
-## Regional scene composition
-
-Extend `screen-redraw.c` so an existing `redraw_scene` can be drawn through a
-set of clipping rectangles.
-
-For every damaged line:
-
-1. Intersect the damage rectangle with that line's scene spans.
-2. Split only at damage boundaries; do not rebuild the complete scene.
-3. Draw intersecting pane content in logical layer order.
-4. Draw window chrome intersecting the same rectangle last.
-
-For a pane span, the scene has already selected the topmost visible pane at
-that position. Composition inside that pane should then be explicit:
-
-1. image placements below the text plane, such as negative Kitty z-indexes;
-2. the text plane, including the requested copy-mode style;
-3. surviving temporal SIXEL placements and images above the text plane;
-4. pane borders, pane status, scrollbars, menus, and other chrome.
-
-The exact placement order is already represented by `struct image_placement`
-and its input protocol, z-index, and serial. Do not derive it from the client's
-output backend.
-
-Only the topmost pane content is normally needed because panes are opaque.
-Underlying pane content is retained in its own grid and becomes visible when a
-floating pane moves, at which time the old floating-pane rectangle is damaged
-and recomposed.
-
-### Image fragments
-
-An `image_span` is placement metadata, not a separately stored bitmap. For an
-intersection, compute the corresponding source-cell rectangle and ask the
-backend to emit that crop from its cached rendering.
-
-- Do not rerun quantization or dithering for every small damage rectangle.
-- SIXEL output operates in six-pixel vertical bands. Expand or clip the
-  backend operation as required, then ensure any additionally touched cells
-  are included in the same composition pass.
-- A transparent top image requires lower image layers to be drawn first.
-- Kitty placements may be deleted, clipped, or replaced only within the
-  damaged placement region.
-
-## Fast text writes
-
-Do not route every ordinary character through a deferred full compositor.
-
-For an application text write:
-
-1. Apply input-protocol damage rules to the logical image spans. For example,
-   text written after a SIXEL image removes the affected SIXEL coverage.
-2. Test whether the affected cells still intersect any image layer or scene
-   overlay requiring composition.
-3. If not, retain the existing direct `tty_cmd_cell`/`tty_cmd_cells` path.
-4. If they do, suppress conflicting direct terminal repair and enqueue only
-   those cells for regional composition.
-
-This decision belongs above the backend-specific tty output functions. Avoid
-callbacks such as `image_draw_after_text()` from several `tty_cmd_*` functions;
-they reproduce ordering logic in multiple places.
-
-## Selection and copy mode
-
-Copy mode must not mutate the application's logical image placements.
-
-- Treat selection as a temporary tmux UI style on the text plane.
-- Follow the chosen policy that selection highlighting does not overwrite
-  image-covered cells.
-- Mouse motion should damage only cells whose selection state actually
-  changed.
-- If changed selection cells do not intersect visible images, draw them using
-  the normal text fast path.
-- If they intersect an image canvas, compose those cells once; do not erase a
-  whole image or pane.
-- Entering or leaving copy mode should damage the visible pane rectangle once,
-  not repeatedly for every unchanged mouse event.
-
-Copy-mode image spans should be copied before its text view is composed, but
-this should be implemented through the same logical state and damage API, not
-through special tty repair calls.
-
-## Floating panes
-
-### Focus changes
-
-Changing the active pane should damage only cells whose appearance changes:
-
-- affected pane borders;
-- pane status cells whose style or contents change; and
-- any active-pane indicators.
-
-It must not redraw pane interiors or retransmit unrelated SIXEL images.
-
-### Moving or resizing a floating pane
-
-For an old rectangle `A` and new rectangle `B`:
-
-- invalidate the scene geometry;
-- damage `A union B` (represented as a few rectangles rather than necessarily
-  one large bounding box);
-- rebuild the scene because pane ownership changed;
-- recompose only spans intersecting those rectangles.
-
-The old rectangle restores tiled panes and any image fragments that were
-previously hidden. The new rectangle draws the floating pane and its chrome.
-Multiple overlapping floating panes follow their window z-order.
-
-## Scrolling
-
-Implement scrolling in three stages. Do not begin with the most complicated
-native-scroll optimization.
-
-### Stage 1: correct regional redraw
-
-1. Move grid text and image spans using the existing grid operations.
-2. Record the pane scroll rectangle and newly exposed rows.
-3. Recompose that rectangle from the completed logical scene.
-
-This may still retransmit more image data than desired, but it establishes a
-correct regional baseline without pane- or window-wide redraws.
-
-### Stage 2: native scrolling without obstructions
-
-Use the terminal's native scroll operation only when:
-
-- the backend/terminal is known to scroll its image pixels consistently;
-- the source and destination rectangle belong to the same visible pane;
-- no floating pane, menu, overlay, pane border/status, or reserved scrollbar
-  intersects it;
-- required vertical and horizontal margins are available and reliable; and
-- existing BCE and terminal-size checks permit the operation.
-
-After native scrolling, compose only newly exposed rows and any protocol-sized
-boundary expansion.
-
-### Stage 3: mixed native scrolling around obstructions
-
-Derive safe rectangles from visible scene spans:
-
-- a destination cell is native-scrollable only when its source cell and
-  destination cell are both visible parts of the same pane;
-- coalesce equal horizontal ranges across adjacent rows into rectangles;
-- native-scroll those maximal rectangles;
-- recompose cells crossing an obstruction boundary and newly exposed cells.
-
-With one floating pane, left and right strips can often scroll over the full
-height. Above and below it, cells whose source crosses behind the floating pane
-must be recomposed rather than recovered from terminal pixels.
-
-As a simpler optional strategy, native-scroll the full tiled-pane rectangle
-and recompose the floating pane's old/current rectangles afterward. This is
-correct if all disturbed cells are marked, but may visibly flash without
-synchronized output. Prefer safe-rectangle scrolling once correctness is
-established.
-
-If rectangle decomposition becomes too fragmented, fall back to regional
-composition. It is an optimization, never a separate correctness path.
-
-## Redraw scheduling
-
-Do not turn queued regional damage into `CLIENT_REDRAWWINDOW` merely because
-the tty output buffer is nonempty. Preserve the damage list and process it
-after output drains.
-
-Use full redraw only for:
-
-- initial attachment;
-- client or terminal geometry changes;
-- a terminal reset or invalid backend cache;
-- layout/viewport changes where rebuilding and clipping regions is not yet
-  safe; or
-- a damage union large enough that full redraw is cheaper.
-
-Focus changes, selection changes, ordinary scrolling, and moving one floating
-pane should remain regional.
-
-## Debugging instrumentation
-
-Add temporary debug logging before optimizing:
-
-- damage reason and window rectangle;
-- client clipping and coordinate translation;
-- scene generation used;
-- native-scroll rectangles selected;
-- spans recomposed in each layer phase; and
-- image fragments emitted by each backend.
-
-The log should make it possible to answer, for every SIXEL retransmission,
-which damage rectangle required it. Remove excessively noisy instrumentation
-before the final commit or keep it behind normal verbose logging.
-
-## Tests
-
-Build the tests before each optimization and keep each test focused on one
-invariant.
-
-### Automated regressions
-
-1. **No-image baseline:** ordinary output, scrolling, copy mode, floating pane
-   focus, borders, status lines, and scrollbars behave unchanged.
-2. **Focus only:** changing focus with a SIXEL elsewhere emits no SIXEL DCS and
-   updates only the affected border/status cells.
-3. **Selection outside image:** emits no image output.
-4. **Selection crossing image:** the image remains intact during and after the
-   drag; only changed non-image cells are highlighted.
-5. **Unobstructed scroll:** logical image spans move with text; where native
-   scrolling is supported, no complete SIXEL retransmission occurs.
-6. **Scroll with floating pane:** both pane-status lines, borders, scrollbar,
-   floating-pane contents, and visible image fragments remain correct.
-7. **Move floating pane:** old and new rectangles are restored; unrelated image
-   regions are not emitted.
-8. **Multiple floating panes:** overlapping z-order remains correct while the
-   top pane moves.
-9. **Transparent placement:** lower images/text show through correctly, and
-   moving/selection does not treat transparency as absent placement geometry.
-10. **Cross-backend clients:** the same input scene produces equivalent results
-    on Kitty, SIXEL, and fallback clients attached simultaneously.
-11. **Pane status top/bottom:** unchanged status contents are physically
-    restored if their cells were damaged.
-12. **Scrollbar reserved/overlay:** scroll thumb and track remain present and
-    images do not overwrite them.
-
-Where possible, capture raw terminal output and assert both presence and
-absence of DCS/APC sequences. `capture-pane` alone cannot prove physical output
-ordering because it observes logical grid contents rather than terminal image
-pixels.
-
-### Manual matrix
-
-Test at least:
-
-- Microsoft Terminal with SIXEL;
-- Mintty with SIXEL;
-- WezTerm with SIXEL;
-- Kitty with Kitty output;
-- a Kitty client attached to a session created from a SIXEL client and the
-  reverse; and
-- a terminal without graphical image support.
-
-For each, test scrolling by application output and mouse wheel, selecting text,
-entering/leaving copy mode, changing focus, opening/closing/moving a floating
-pane, pane status at top and bottom, and scrollbars.
-
-## Implementation steps and commit boundaries
-
-This must not be implemented as one monolithic change. Each numbered step is a
-separate commit, review, and testing gate. Do not begin the next step until the
-current step passes its focused tests. If a step exposes a pre-existing bug,
-record it before expanding the patch.
-
-### Step 0: archive the experiment and recover the baseline
-
-**Goal:** Begin development from known source rather than repairing the mixed
-experimental diff.
-
-**Work:**
-
-- Preserve the current diff and this plan on a clearly named WIP branch.
-- Return `4902-image-support` to clean commit `ec9859b1`.
-- Build with and without image support.
-- Run the existing image regression and ordinary tmux regression suite.
-
-**Gate:** The branch is clean and existing behaviour is reproduced. No product
-code is changed in this step.
-
-### Step 1: add focused regressions and tracing
-
-**Goal:** Establish observable failures before changing redraw behaviour.
-
-**Primary files:** `regress/image-support.sh`, temporary debug logging in
-`screen-redraw.c` if necessary.
-
-**Work:** Add independent tests for focus-only changes, selection crossing an
-image, unobstructed scrolling, scrolling beneath a floating pane, moving a
-floating pane, both pane-status lines, and scrollbars. Raw terminal output must
-be used where a test needs to prove that SIXEL or Kitty data was or was not
-emitted.
-
-**Gate:** Each test either passes on the baseline or has a documented expected
-failure. Tests must not depend on timing races or visual screenshots. The
-existing edge-case checks introduced by `a4abd616` must pass unchanged on the
-recovery baseline and establish the semantic compatibility result expected by
-later gates.
-
-**Not included:** No redraw implementation changes.
-
-### Step 2: introduce regional damage scheduling
-
-**Goal:** Represent and preserve small window-coordinate damage rectangles
-without changing the rendered result.
-
-**Primary files:** `screen-redraw.c`, `server-client.c`, minimal declarations in
-`tmux.h`.
-
-**Work:** Add per-client damage storage, clipping, merging, a complexity cap,
-and verbose logging. Existing callers may initially convert the damage to the
-same redraw they used before. Pending tty output must retain the region rather
-than promote it automatically to a full-window redraw.
-
-**Gate:** No-image and image output remain visually and byte-for-byte equivalent
-where practical. Unit-style tests verify rectangle clipping and merging.
-
-**Not included:** No image-layer traversal, selection changes, floating-pane
-optimization, or native scrolling.
-
-### Step 3: add a generic image-region composition API
-
-**Goal:** Give the scene compositor one protocol-independent way to render the
-image layers intersecting a cell rectangle.
-
-**Primary files:** `image.c`, `image-sixel.c`, `image-kitty.c`, with only generic
-prototypes in `tmux.h`.
-
-**Work:**
-
-- In `image.c`, intersect damage with placement spans and preserve logical
-  input/z/serial order.
-- In `image-sixel.c`, emit a crop from cached quantized data and handle SIXEL
-  band alignment.
-- In `image-kitty.c`, update/delete/place only the intersecting cached
-  placements.
-- Define clearly separate below-text and above-text passes.
-
-**Gate:** Rendering a whole image as adjacent damaged rectangles produces the
-same final scene as rendering it in one operation. Test transparent and
-overlapping placements on both output backends. The `a4abd616` semantic
-compatibility checks must continue to pass unchanged.
-
-**Not included:** No changes to individual tty text commands and no native
-scroll optimization.
-
-### Step 4: clip scene composition to damage rectangles
-
-**Goal:** Make `screen-redraw.c` repaint only scene spans intersecting queued
-damage.
-
-**Primary files:** `screen-redraw.c`; generic calls into `image.c`.
-
-**Work:** For each damaged line, intersect existing redraw spans, compose the
-selected pane's below-text images, text, and above-text images, then draw
-intersecting chrome last. Full redraw continues to use the same compositor with
-a full-client damage rectangle.
-
-**Gate:** Full and tiled panes redraw correctly; pane borders, pane status,
-scrollbars, menus, and images have deterministic output order. No floating-pane
-movement or scroll optimization is added yet.
-
-### Step 5: route text and selection damage through the compositor
-
-**Goal:** Repair only cells where text or copy-mode selection interacts with
-image layers.
-
-**Primary files:** `screen-write.c`, `window-copy.c`, `screen-redraw.c`, and
-logical helpers in `image.c`.
-
-**Work:** Apply input semantics to logical spans first. Preserve direct tty text
-output when no image placement intersects the cells. Otherwise enqueue those
-cells for composition. Selection changes damage only cells whose selection
-state changed and follow the policy of not overwriting image-covered cells.
-
-**Gate:** Dragging selection across an image never damages it, entering/leaving
-copy mode restores the same scene, and selection outside images emits no image
-data. The `a4abd616` semantic compatibility checks must continue to pass
-unchanged.
-
-**Not included:** Do not add image callbacks to `tty_cmd_cell`,
-`tty_cmd_cells`, or `tty_cmd_clearcharacter`.
-
-### Step 6: make floating-pane changes regional
-
-**Goal:** Focus, movement, resize, open, and close operations damage only the
-cells whose scene ownership or chrome changed.
-
-**Primary files:** floating-pane/window code that reports geometry changes,
-plus `screen-redraw.c`. Image implementation remains in the image files.
-
-**Work:** Focus changes enqueue border/status cells only. Movement and resize
-enqueue the old and new pane rectangles and invalidate scene geometry. Regional
-composition restores underlying panes/images in the old rectangle and draws
-the floating pane in the new rectangle.
-
-**Gate:** Changing focus emits no unrelated SIXEL/APC. Moving a floating pane
-does not damage images, either pane-status line, borders, or scrollbars. Test
-one and multiple overlapping floating panes.
-
-### Step 7: implement correct regional scrolling without native optimization
-
-**Goal:** Establish correct scrolling using logical state plus regional
-composition.
-
-**Primary files:** grid/image state helpers in `image.c`, damage reporting in
-`screen-write.c`, composition in `screen-redraw.c`.
-
-**Work:** Move text and image spans first, then damage the scroll rectangle and
-compose it. Do not use special image repair from `tty.c`.
-
-**Gate:** Application scrolling, mouse-wheel copy-mode scrolling, partial
-scroll regions, scrollbars, and scrolling beneath floating panes are correct on
-Kitty, Microsoft Terminal, Mintty, and WezTerm. This step may redraw more than
-the final optimized version, but must not redraw outside the scroll rectangle.
-The `a4abd616` semantic compatibility checks must continue to pass unchanged.
-
-### Step 8: enable native scrolling for unobstructed rectangles
-
-**Goal:** Avoid retransmitting image pixels when the terminal can safely move
-them.
-
-**Primary files:** scroll planning in `screen-redraw.c`, generic backend
-capability in `image.c`, backend facts in `image-sixel.c` and `image-kitty.c`,
-terminal primitive execution in `tty.c`.
-
-**Work:** Select native scrolling only when source/destination cells belong to
-the same unobstructed pane and terminal margins/backend behaviour permit it.
-Compose newly exposed rows afterward. Retain Step 7 as the fallback.
-
-**Gate:** Raw output proves the native scroll is used and a complete image is
-not retransmitted. Final output must match Step 7 on every tested backend.
-
-### Step 9: decompose scrolling around floating panes
-
-**Goal:** Combine native scrolling of safe rectangles with composition of
-obstructed and boundary rectangles.
-
-**Primary files:** scroll planning and scene-span traversal in
-`screen-redraw.c`; no new protocol logic outside the image files.
-
-**Work:** Derive maximal rectangles where both source and destination are
-visible cells of the same pane, coalesce adjacent equal ranges, natively scroll
-them, and compose everything else. Enforce a fragmentation threshold that
-falls back to Step 7.
-
-**Gate:** Scrolling beneath one or several floating panes produces the same
-final scene as Step 7, reduces emitted image data, and never loses pane status,
-borders, scrollbars, or images.
-
-### Step 10: cleanup, performance checks, and full regression
-
-**Goal:** Remove superseded paths only after all replacements are proven.
-
-**Work:** Remove obsolete redraw helpers and flags introduced or made unused by
-the new path. Reduce temporary logging. Check memory growth, rectangle-list
-bounds, output byte counts, and behaviour without image support. Run the entire
-regression suite and the manual terminal matrix.
-
-**Gate:** All completion criteria below are satisfied. Synchronized output may
-improve appearance, but disabling it does not alter final contents. The
-`a4abd616` semantic compatibility checks must continue to pass unchanged.
-
-Do not squash these implementation steps during development. Keeping their
-boundaries visible makes it possible to bisect correctness and performance
-regressions. They can be reorganized later only after review.
-
-## Completion criteria
-
-The work is complete when:
-
-- Mintty, Microsoft Terminal, WezTerm, and Kitty show no persistent damage;
-- focus and selection do not retransmit unrelated images;
-- floating-pane movement redraws only old/new affected regions;
-- scrolling preserves images, pane borders, both tiled and floating pane
-  status lines, and scrollbars;
-- input semantics produce the same composition on every output backend;
-- no-image performance and behaviour remain unchanged;
-- full regression tests pass; and
-- synchronized output improves appearance but disabling it never changes the
-  final screen contents.

Makefile.am

@@ -5,8 +5,7 @@ CLEANFILES = tmux.1.mdoc tmux.1.man cmd-parse.c
 # Distribution tarball options.
 EXTRA_DIST = \
 	CHANGES README COPYING example_tmux.conf \
-	osdep-*.c mdoc2man.awk tmux.1 \
-	tools/generate-image-diacritics.sh
+	osdep-*.c mdoc2man.awk tmux.1
 dist_EXTRA_tmux_SOURCES = compat/*.[ch]
 
 # Preprocessor flags.
@@ -175,6 +174,7 @@ dist_tmux_SOURCES = \
 	input-keys.c \
 	input.c \
 	job.c \
+	json.c \
 	key-bindings.c \
 	key-string.c \
 	layout-custom.c \
@@ -247,9 +247,9 @@ if HAVE_UTF8PROC
 nodist_tmux_SOURCES += compat/utf8proc.c
 endif
 
-# Enable image support.
-if ENABLE_IMAGES
-dist_tmux_SOURCES += image.c image-sixel.c image-kitty.c
+# Enable sixel support.
+if ENABLE_SIXEL
+dist_tmux_SOURCES += image.c image-sixel.c
 endif
 
 # Add bits for fuzzing if enabled.

arguments.c

@@ -1,4 +1,4 @@
-/* $OpenBSD: arguments.c,v 1.66 2026/06/26 09:54:56 nicm Exp $ */
+/* $OpenBSD: arguments.c,v 1.67 2026/08/25 06:04:33 nicm Exp $ */
 
 /*
  * Copyright (c) 2010 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -762,8 +762,6 @@ args_make_commands_now(struct cmd *self, struct cmdq_item *item, u_int idx,
 		cmdq_error(item, "%s", error);
 		free(error);
 	}
-	else
-		cmdlist->references++;
 	args_make_commands_free(state);
 	return (cmdlist);
 }
@@ -827,8 +825,10 @@ args_make_commands(struct args_command_state *state, int argc, char **argv,
 	int			 i;
 
 	if (state->cmdlist != NULL) {
-		if (argc == 0)
+		if (argc == 0) {
+			state->cmdlist->references++;
 			return (state->cmdlist);
+		}
 		return (cmd_list_copy(state->cmdlist, argc, argv));
 	}
 

client.c

@@ -1,4 +1,4 @@
-/* $OpenBSD: client.c,v 1.167 2026/08/17 07:56:56 nicm Exp $ */
+/* $OpenBSD: client.c,v 1.168 2026/08/17 20:14:31 nicm Exp $ */
 
 /*
  * Copyright (c) 2007 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -712,6 +712,9 @@ client_dispatch_wait(struct imsg *imsg)
 		fprintf(stderr, "server version is too old for client\n");
 		proc_exit(client_proc);
 		break;
+	default:
+		log_debug("unknown message type %u", imsg->hdr.type);
+		break;
 	}
 }
 
@@ -798,5 +801,8 @@ client_dispatch_attached(struct imsg *imsg)
 		system(data);
 		proc_send(client_peer, MSG_UNLOCK, -1, NULL, 0);
 		break;
+	default:
+		log_debug("unknown message type %u", imsg->hdr.type);
+		break;
 	}
 }

cmd-capture-pane.c

@@ -1,4 +1,4 @@
-/* $OpenBSD: cmd-capture-pane.c,v 1.68 2026/07/20 11:16:33 nicm Exp $ */
+/* $OpenBSD: cmd-capture-pane.c,v 1.69 2026/09/08 07:31:59 nicm Exp $ */
 
 /*
  * Copyright (c) 2009 Jonathan Alvarado <radobobo@users.sourceforge.net>
@@ -42,8 +42,8 @@ const struct cmd_entry cmd_capture_pane_entry = {
 	.name = "capture-pane",
 	.alias = "capturep",
 
-	.args = { "ab:CeE:FHJLMNpPqRS:Tt:", 0, 0, NULL },
-	.usage = "[-aCeFHJLMNpPqRT] " CMD_BUFFER_USAGE " [-E end-line] "
+	.args = { "ab:CeE:FHIJLMNpPqRS:Tt:", 0, 0, NULL },
+	.usage = "[-aCeFHIJLMNpPqRT] " CMD_BUFFER_USAGE " [-E end-line] "
 		 "[-S start-line] " CMD_TARGET_PANE_USAGE,
 
 	.target = { 't', CMD_FIND_PANE, 0 },
@@ -200,7 +200,7 @@ cmd_capture_pane_pending(struct args *args, struct window_pane *wp,
 				tmp[0] = line[i];
 				tmp[1] = '\0';
 			} else
-				xsnprintf(tmp, sizeof tmp, "\\%03hho", line[i]);
+				snprintf(tmp, sizeof tmp, "\\%03hho", line[i]);
 			buf = cmd_capture_pane_append(buf, len, tmp,
 			    strlen(tmp));
 		}
@@ -259,7 +259,7 @@ cmd_capture_pane_history(struct args *args, struct cmdq_item *item,
 	struct grid_cell		*gc = NULL;
 	struct window_mode_entry	*wme;
 	int				 n, join_lines, number_lines, flags = 0;
-	int				 show_flags, hyperlinks;
+	int				 show_flags, show_time, hyperlinks;
 	u_int				*links = NULL, nlinks = 0;
 	u_int				 i, sx, top, bottom, tmp;
 	char				*cause, *buf = NULL, *line, b[64], *cp;
@@ -342,6 +342,7 @@ cmd_capture_pane_history(struct args *args, struct cmdq_item *item,
 		flags |= GRID_STRING_TRIM_SPACES;
 	number_lines = args_has(args, 'L');
 	show_flags = args_has(args, 'F');
+	show_time = args_has(args, 'I');
 	hyperlinks = args_has(args, 'H');
 	if (hyperlinks)
 		links = xreallocarray(NULL, gd->sx, sizeof *links);
@@ -358,6 +359,7 @@ cmd_capture_pane_history(struct args *args, struct cmdq_item *item,
 			free(line);
 			continue;
 		}
+		gl = grid_peek_line(gd, i);
 
 		if (number_lines) {
 			if (i >= gd->hsize)
@@ -368,11 +370,16 @@ cmd_capture_pane_history(struct args *args, struct cmdq_item *item,
 			if (n >= 0)
 				buf = cmd_capture_pane_append(buf, len, b, n);
 		}
+		if (show_time) {
+			n = snprintf(b, sizeof b, "%llu ",
+			    (unsigned long long)grid_line_time(gl));
+			if (n >= 0)
+				buf = cmd_capture_pane_append(buf, len, b, n);
+		}
 		if (show_flags) {
 			cp = b;
 			*cp = '\0';
 
-			gl = grid_peek_line(gd, i);
 			if (gl->flags & GRID_LINE_DEAD)
 				*cp++ = 'D';
 			if (gl->flags & GRID_LINE_HYPERLINK)
@@ -393,7 +400,6 @@ cmd_capture_pane_history(struct args *args, struct cmdq_item *item,
 		}
 		buf = cmd_capture_pane_append(buf, len, line, linelen);
 
-		gl = grid_peek_line(gd, i);
 		if (!join_lines || !(gl->flags & GRID_LINE_WRAPPED))
 			buf[(*len)++] = '\n';
 

cmd-command-prompt.c

@@ -1,4 +1,4 @@
-/* $OpenBSD: cmd-command-prompt.c,v 1.75 2026/06/25 11:39:11 nicm Exp $ */
+/* $OpenBSD: cmd-command-prompt.c,v 1.76 2026/08/25 06:04:33 nicm Exp $ */
 
 /*
  * Copyright (c) 2008 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -242,9 +242,11 @@ cmd_command_prompt_callback(struct client *c, void *data, const char *s,
 	} else if (item == NULL) {
 		new_item = cmdq_get_command(cmdlist, NULL);
 		cmdq_append(c, new_item);
+		cmd_list_free(cmdlist);
 	} else {
 		new_item = cmdq_get_command(cmdlist, cmdq_get_state(item));
 		cmdq_insert_after(item, new_item);
+		cmd_list_free(cmdlist);
 	}
 	cmd_free_argv(argc, argv);
 

cmd-display-menu.c

@@ -1,4 +1,4 @@
-/* $OpenBSD: cmd-display-menu.c,v 1.52 2026/07/14 19:07:03 nicm Exp $ */
+/* $OpenBSD: cmd-display-menu.c,v 1.53 2026/08/31 07:46:55 nicm Exp $ */
 
 /*
  * Copyright (c) 2019 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -591,6 +591,8 @@ cmd_display_popup_exec(struct cmd *self, struct cmdq_item *item)
 		server_client_clear_overlay(tc);
 		return (CMD_RETURN_NORMAL);
 	}
+	if (tc->flags & CLIENT_CONTROL)
+		return (CMD_RETURN_NORMAL);
 	if (!modify && tc->overlay_draw != NULL)
 		return (CMD_RETURN_NORMAL);
 

cmd-display-message.c

@@ -1,4 +1,4 @@
-/* $OpenBSD: cmd-display-message.c,v 1.65 2026/02/23 08:46:57 nicm Exp $ */
+/* $OpenBSD: cmd-display-message.c,v 1.66 2026/09/08 08:33:10 nicm Exp $ */
 
 /*
  * Copyright (c) 2009 Tiago Cunha <me@tiagocunha.org>
@@ -39,8 +39,8 @@ const struct cmd_entry cmd_display_message_entry = {
 	.name = "display-message",
 	.alias = "display",
 
-	.args = { "aCc:d:lINpt:F:v", 0, 1, NULL },
-	.usage = "[-aCIlNpv] [-c target-client] [-d delay] [-F format] "
+	.args = { "aCc:d:jlINpt:F:v", 0, 1, NULL },
+	.usage = "[-aCIjlNpv] [-c target-client] [-d delay] [-F format] "
 		 CMD_TARGET_PANE_USAGE " [message]",
 
 	.target = { 't', CMD_FIND_PANE, CMD_FIND_CANFAIL },
@@ -67,14 +67,15 @@ cmd_display_message_exec(struct cmd *self, struct cmdq_item *item)
 	struct winlink		*wl = target->wl;
 	struct window_pane	*wp = target->wp;
 	const char		*template;
-	char			*msg, *cause;
+	char			*msg, *cause = NULL;
 	int			 delay = -1, flags, Nflag = args_has(args, 'N');
 	int			 Cflag = args_has(args, 'C');
 	struct format_tree	*ft;
 	u_int			 count = args_count(args);
 	struct evbuffer		*evb;
+	struct json_node	*jn;
 
-	if (args_has(args, 'I')) {
+	if (args_has(args, 'I') && !args_has(args, 'j')) {
 		if (wp == NULL)
 			return (CMD_RETURN_NORMAL);
 		switch (window_pane_start_input(wp, item, &cause)) {
@@ -107,7 +108,9 @@ cmd_display_message_exec(struct cmd *self, struct cmdq_item *item)
 		template = args_string(args, 0);
 	else
 		template = args_get(args, 'F');
-	if (template == NULL)
+	if (args_has(args, 'j') && template == NULL)
+		template = "";
+	else if (template == NULL)
 		template = DISPLAY_MESSAGE_TEMPLATE;
 
 	/*
@@ -129,7 +132,7 @@ cmd_display_message_exec(struct cmd *self, struct cmdq_item *item)
 	ft = format_create(cmdq_get_client(item), item, FORMAT_NONE, flags);
 	format_defaults(ft, c, s, wl, wp);
 
-	if (args_has(args, 'a')) {
+	if (args_has(args, 'a') && !args_has(args, 'j')) {
 		format_each(ft, cmd_display_message_each, item);
 		format_free(ft);
 		return (CMD_RETURN_NORMAL);
@@ -139,6 +142,19 @@ cmd_display_message_exec(struct cmd *self, struct cmdq_item *item)
 		msg = xstrdup(template);
 	else
 		msg = format_expand_time(ft, template);
+	if (args_has(args, 'j')) {
+		jn = json_parse(msg, &cause);
+		if (jn == NULL) {
+			cmdq_error(item, "%s", cause);
+			free(cause);
+			free(msg);
+			format_free(ft);
+			return (CMD_RETURN_ERROR);
+		}
+		free(msg);
+		msg = json_to_string(jn);
+		json_destroy_node(jn);
+	}
 
 	if (cmdq_get_client(item) == NULL)
 		cmdq_error(item, "%s", msg);

cmd-find.c

@@ -1,4 +1,4 @@
-/* $OpenBSD: cmd-find.c,v 1.87 2026/07/17 12:42:51 nicm Exp $ */
+/* $OpenBSD: cmd-find.c,v 1.88 2026/09/07 12:05:12 nicm Exp $ */
 
 /*
  * Copyright (c) 2015 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -388,9 +388,11 @@ cmd_find_get_window_with_session(struct cmd_find_state *fs, const char *window)
 
 	/* Try as an offset. */
 	if (!exact && (window[0] == '+' || window[0] == '-')) {
-		if (window[1] != '\0')
-			n = strtonum(window + 1, 1, INT_MAX, NULL);
-		else
+		if (window[1] != '\0') {
+			n = strtonum(window + 1, 1, INT_MAX, &errstr);
+			if (errstr != NULL)
+				return (-1);
+		} else
 			n = 1;
 		s = fs->s;
 		if (fs->flags & CMD_FIND_WINDOW_INDEX) {
@@ -626,9 +628,11 @@ cmd_find_get_pane_with_window(struct cmd_find_state *fs, const char *pane)
 
 	/* Try as an offset. */
 	if (pane[0] == '+' || pane[0] == '-') {
-		if (pane[1] != '\0')
-			n = strtonum(pane + 1, 1, INT_MAX, NULL);
-		else
+		if (pane[1] != '\0') {
+			n = strtonum(pane + 1, 1, INT_MAX, &errstr);
+			if (errstr != NULL)
+				return (-1);
+		} else
 			n = 1;
 		wp = fs->w->active;
 		if (pane[0] == '+')

cmd-if-shell.c

@@ -1,4 +1,4 @@
-/* $OpenBSD: cmd-if-shell.c,v 1.86 2025/08/01 09:05:51 nicm Exp $ */
+/* $OpenBSD: cmd-if-shell.c,v 1.87 2026/08/25 06:04:33 nicm Exp $ */
 
 /*
  * Copyright (c) 2009 Tiago Cunha <me@tiagocunha.org>
@@ -98,6 +98,7 @@ cmd_if_shell_exec(struct cmd *self, struct cmdq_item *item)
 			return (CMD_RETURN_ERROR);
 		new_item = cmdq_get_command(cmdlist, cmdq_get_state(item));
 		cmdq_insert_after(item, new_item);
+		cmd_list_free(cmdlist);
 		return (CMD_RETURN_NORMAL);
 	}
 
@@ -164,9 +165,11 @@ cmd_if_shell_callback(struct job *job)
 	} else if (item == NULL) {
 		new_item = cmdq_get_command(cmdlist, NULL);
 		cmdq_append(c, new_item);
+		cmd_list_free(cmdlist);
 	} else {
 		new_item = cmdq_get_command(cmdlist, cmdq_get_state(item));
 		cmdq_insert_after(item, new_item);
+		cmd_list_free(cmdlist);
 	}
 
 out:

cmd-list-panes.c

@@ -1,4 +1,4 @@
-/* $OpenBSD: cmd-list-panes.c,v 1.40 2026/06/01 14:01:09 nicm Exp $ */
+/* $OpenBSD: cmd-list-panes.c,v 1.41 2026/09/08 10:20:08 nicm Exp $ */
 
 /*
  * Copyright (c) 2009 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -97,6 +97,7 @@ cmd_list_panes_window(struct cmd *self, struct session *s, struct winlink *wl,
     struct cmdq_item *item, int type)
 {
 	struct args		*args = cmd_get_args(self);
+	struct client		*c = cmdq_get_client(item);
 	struct window_pane	*wp, **l;
 	u_int			 i, n;
 	struct format_tree	*ft;
@@ -147,7 +148,7 @@ cmd_list_panes_window(struct cmd *self, struct session *s, struct winlink *wl,
 		wp = l[i];
 		ft = format_create(cmdq_get_client(item), item, FORMAT_NONE, 0);
 		format_add(ft, "line", "%u", n);
-		format_defaults(ft, NULL, s, wl, wp);
+		format_defaults(ft, c, s, wl, wp);
 
 		if (filter != NULL) {
 			expanded = format_expand(ft, filter);

cmd-list-sessions.c

@@ -1,4 +1,4 @@
-/* $OpenBSD: cmd-list-sessions.c,v 1.36 2026/02/27 08:25:12 nicm Exp $ */
+/* $OpenBSD: cmd-list-sessions.c,v 1.37 2026/09/08 10:20:08 nicm Exp $ */
 
 /*
  * Copyright (c) 2007 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -53,6 +53,7 @@ static enum cmd_retval
 cmd_list_sessions_exec(struct cmd *self, struct cmdq_item *item)
 {
 	struct args		 *args = cmd_get_args(self);
+	struct client		 *c = cmdq_get_client(item);
 	struct session		**l;
 	u_int		 	  n, i;
 	struct format_tree	 *ft;
@@ -76,7 +77,7 @@ cmd_list_sessions_exec(struct cmd *self, struct cmdq_item *item)
 	for (i = 0; i < n; i++) {
 		ft = format_create(cmdq_get_client(item), item, FORMAT_NONE, 0);
 		format_add(ft, "line", "%u", i);
-		format_defaults(ft, NULL, l[i], NULL, NULL);
+		format_defaults(ft, c, l[i], NULL, NULL);
 
 		if (filter != NULL) {
 			expanded = format_expand(ft, filter);

cmd-list-windows.c

@@ -1,4 +1,4 @@
-/* $OpenBSD: cmd-list-windows.c,v 1.50 2026/02/27 08:25:12 nicm Exp $ */
+/* $OpenBSD: cmd-list-windows.c,v 1.51 2026/09/08 10:20:08 nicm Exp $ */
 
 /*
  * Copyright (c) 2007 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -60,6 +60,7 @@ cmd_list_windows_exec(struct cmd *self, struct cmdq_item *item)
 {
 	struct args		*args = cmd_get_args(self);
 	struct cmd_find_state	*target = cmdq_get_target(item);
+	struct client		*c = cmdq_get_client(item);
 	struct winlink		*wl, **l;
 	struct session		*s;
 	u_int			 i, n;
@@ -94,7 +95,7 @@ cmd_list_windows_exec(struct cmd *self, struct cmdq_item *item)
 		s = wl->session;
 		ft = format_create(cmdq_get_client(item), item, FORMAT_NONE, 0);
 		format_add(ft, "line", "%u", n);
-		format_defaults(ft, NULL, s, wl, NULL);
+		format_defaults(ft, c, s, wl, NULL);
 
 		if (filter != NULL) {
 			expanded = format_expand(ft, filter);

cmd-new-window.c

@@ -1,4 +1,4 @@
-/* $OpenBSD: cmd-new-window.c,v 1.103 2026/07/08 08:07:42 nicm Exp $ */
+/* $OpenBSD: cmd-new-window.c,v 1.104 2026/09/03 21:04:11 nicm Exp $ */
 
 /*
  * Copyright (c) 2007 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -60,7 +60,8 @@ cmd_new_window_exec(struct cmd *self, struct cmdq_item *item)
 	struct client		*tc = cmdq_get_target_client(item);
 	struct session		*s = target->s;
 	struct winlink		*wl = target->wl, *new_wl = NULL;
-	int			 idx = target->idx, before, count = args_count(args);
+	int			 idx = target->idx, before;
+	int			 count = args_count(args);
 	char			*cause = NULL, *cp, *expanded, *wname = NULL;
 	const char		*template, *name;
 	struct cmd_find_state	 fs;
@@ -74,8 +75,10 @@ cmd_new_window_exec(struct cmd *self, struct cmdq_item *item)
 	}
 
 	/*
-	 * If -S and -n are given and -t is not and a single window with this
-	 * name already exists, select it.
+	 * If -S is given, select an existing window instead of creating a
+	 * new one: preferring -t if it already points at a window, or
+	 * otherwise -n if one exists with that name. If neither matches,
+	 * fall through and create a window as normal.
 	 */
 	name = args_get(args, 'n');
 	if (name != NULL) {
@@ -88,32 +91,39 @@ cmd_new_window_exec(struct cmd *self, struct cmdq_item *item)
 		wname = clean_name(expanded, 0);
 		free(expanded);
 	}
-	if (args_has(args, 'S') && wname != NULL && target->idx == -1) {
-		expanded = format_single(item, wname, c, s, NULL, NULL);
-		RB_FOREACH(wl, winlinks, &s->windows) {
-			if (strcmp(wl->window->name, expanded) != 0)
-				continue;
-			if (new_wl == NULL) {
-				new_wl = wl;
-				continue;
+	if (args_has(args, 'S')) {
+		if (idx != -1)
+			new_wl = winlink_find_by_index(&s->windows, idx);
+		else if (wname != NULL) {
+			expanded = format_single(item, wname, c, s, NULL, NULL);
+			RB_FOREACH(wl, winlinks, &s->windows) {
+				if (strcmp(wl->window->name, expanded) != 0)
+					continue;
+				if (new_wl == NULL) {
+					new_wl = wl;
+					continue;
+				}
+				cmdq_error(item, "multiple windows named %s",
+				    wname);
+				free(wname);
+				free(expanded);
+				return (CMD_RETURN_ERROR);
 			}
-			cmdq_error(item, "multiple windows named %s", wname);
-			free(wname);
 			free(expanded);
-			return (CMD_RETURN_ERROR);
 		}
-		free(expanded);
-		if (new_wl != NULL) {
-			free(wname);
-			if (args_has(args, 'd'))
-				return (CMD_RETURN_NORMAL);
-			if (session_set_current(s, new_wl) == 0)
-				server_redraw_session(s);
-			if (c != NULL && c->session != NULL)
-				s->curw->window->latest = c;
-			recalculate_sizes();
+	}
+
+	/* Found an existing window to select instead of creating a new one. */
+	if (new_wl != NULL) {
+		free(wname);
+		if (args_has(args, 'd'))
 			return (CMD_RETURN_NORMAL);
-		}
+		if (session_set_current(s, new_wl) == 0)
+			server_redraw_session(s);
+		if (c != NULL && c->session != NULL)
+			s->curw->window->latest = c;
+		recalculate_sizes();
+		return (CMD_RETURN_NORMAL);
 	}
 
 	before = args_has(args, 'b');

cmd-parse.y

@@ -1,4 +1,4 @@
-/* $OpenBSD: cmd-parse.y,v 1.58 2026/04/27 12:31:11 nicm Exp $ */
+/* $OpenBSD: cmd-parse.y,v 1.60 2026/09/08 10:20:08 nicm Exp $ */
 
 /*
  * Copyright (c) 2019 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -210,7 +210,7 @@ expanded	: format
 				cmd_find_from_client(&fs, c, 0);
 				fsp = &fs;
 			}
-			ft = format_create(NULL, pi->item, FORMAT_NONE, flags);
+			ft = format_create(c, pi->item, FORMAT_NONE, flags);
 			format_defaults(ft, c, fsp->s, fsp->wl, fsp->wp);
 
 			$$ = format_expand(ft, $1);
@@ -802,6 +802,7 @@ cmd_parse_expand_alias(struct cmd_parse_command *cmd,
 	if (last == NULL) {
 		pr->status = CMD_PARSE_SUCCESS;
 		pr->cmdlist = cmd_list_new();
+		cmd_parse_free_commands(cmds);
 		return (1);
 	}
 
@@ -814,6 +815,7 @@ cmd_parse_expand_alias(struct cmd_parse_command *cmd,
 	pi->flags |= CMD_PARSE_NOALIAS;
 	cmd_parse_build_commands(cmds, pi, pr);
 	pi->flags &= ~CMD_PARSE_NOALIAS;
+	cmd_parse_free_commands(cmds);
 	return (1);
 }
 

cmd-queue.c

@@ -1,4 +1,4 @@
-/* $OpenBSD: cmd-queue.c,v 1.122 2026/08/03 13:38:42 nicm Exp $ */
+/* $OpenBSD: cmd-queue.c,v 1.123 2026/08/24 20:34:26 nicm Exp $ */
 
 /*
  * Copyright (c) 2013 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -850,7 +850,18 @@ cmdq_error(struct cmdq_item *item, const char *fmt, ...)
 
 	if (c == NULL) {
 		cmd_get_source(cmd, &file, &line);
-		cfg_add_cause("%s:%u: %s", file, line, msg);
+		if (!cfg_finished) {
+			if (file != NULL)
+				cfg_add_cause("%s:%u: %s", file, line, msg);
+			else
+				cfg_add_cause("%s", msg);
+		} else {
+			if (file != NULL) {
+				server_add_message("message: %s:%u: %s", file,
+				    line, msg);
+			} else
+				server_add_message("message: %s", msg);
+		}
 	} else if (c->session == NULL || (c->flags & CLIENT_CONTROL)) {
 		server_add_message("%s message: %s", c->name, msg);
 		if (~c->flags & CLIENT_UTF8) {

cmd-resize-pane.c

@@ -1,4 +1,4 @@
-/* $OpenBSD: cmd-resize-pane.c,v 1.67 2026/07/10 13:38:45 nicm Exp $ */
+/* $OpenBSD: cmd-resize-pane.c,v 1.68 2026/08/31 07:44:39 nicm Exp $ */
 
 /*
  * Copyright (c) 2009 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -92,6 +92,7 @@ cmd_resize_pane_exec(struct cmd *self, struct cmdq_item *item)
 		return (CMD_RETURN_NORMAL);
 	}
 	server_unzoom_window(w);
+	lc = wp->layout_cell; /* may have been replaced by unzoom */
 
 	if (args_has(args, 'x')) {
 		x = args_percentage(args, 'x', 0, PANE_MAXIMUM, w->sx, &cause);

cmd-run-shell.c

@@ -1,4 +1,4 @@
-/* $OpenBSD: cmd-run-shell.c,v 1.93 2026/07/17 12:42:51 nicm Exp $ */
+/* $OpenBSD: cmd-run-shell.c,v 1.94 2026/08/25 06:04:33 nicm Exp $ */
 
 /*
  * Copyright (c) 2009 Tiago Cunha <me@tiagocunha.org>
@@ -233,9 +233,11 @@ cmd_run_shell_timer(__unused int fd, __unused short events, void* arg)
 	} else if (item == NULL) {
 		new_item = cmdq_get_command(cmdlist, NULL);
 		cmdq_append(c, new_item);
+		cmd_list_free(cmdlist);
 	} else {
 		new_item = cmdq_get_command(cmdlist, cmdq_get_state(item));
 		cmdq_insert_after(item, new_item);
+		cmd_list_free(cmdlist);
 	}
 
 	if (cdata->item != NULL)

cmd-select-layout.c

@@ -1,4 +1,4 @@
-/* $OpenBSD: cmd-select-layout.c,v 1.43 2026/07/10 13:38:45 nicm Exp $ */
+/* $OpenBSD: cmd-select-layout.c,v 1.45 2026/09/09 07:03:39 nicm Exp $ */
 
 /*
  * Copyright (c) 2009 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -73,12 +73,13 @@ cmd_select_layout_exec(struct cmd *self, struct cmdq_item *item)
 {
 	struct args		*args = cmd_get_args(self);
 	struct cmd_find_state	*target = cmdq_get_target(item);
+	struct client		*c = cmdq_get_target_client(item);
 	struct winlink		*wl = target->wl;
 	struct window		*w = wl->window;
 	struct window_pane	*wp = target->wp;
 	const char		*layoutname;
-	char			*oldlayout, *cause;
-	int			 next, previous, layout;
+	char			*oldlayout, *cause = NULL;
+	int			 next, previous, layout, flags = 0;
 
 	server_unzoom_window(w);
 
@@ -89,8 +90,12 @@ cmd_select_layout_exec(struct cmd *self, struct cmdq_item *item)
 	if (args_has(args, 'p'))
 		previous = 1;
 
+	if (c != NULL &&
+	    (c->flags & CLIENT_CONTROL) &&
+	    (~c->flags & CLIENT_CONTROL_NEWLAYOUTS))
+		flags |= LAYOUT_CUSTOM_OLD_FORMAT;
 	oldlayout = w->old_layout;
-	w->old_layout = layout_dump(w, w->layout_root);
+	w->old_layout = layout_dump(w, w->layout_root, flags);
 
 	if (next || previous) {
 		if (next)

cmd-select-pane.c

@@ -1,4 +1,4 @@
-/* $OpenBSD: cmd-select-pane.c,v 1.77 2026/07/17 12:42:51 nicm Exp $ */
+/* $OpenBSD: cmd-select-pane.c,v 1.78 2026/08/20 09:19:24 nicm Exp $ */
 
 /*
  * Copyright (c) 2009 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -160,6 +160,7 @@ cmd_select_pane_exec(struct cmd *self, struct cmdq_item *item)
 	char			*title;
 	const char		*style;
 	struct options_entry	*o;
+	int			 visible, Zflag = args_has(args, 'Z');
 
 	if (entry == &cmd_last_pane_entry || args_has(args, 'l')) {
 		/*
@@ -185,14 +186,18 @@ cmd_select_pane_exec(struct cmd *self, struct cmdq_item *item)
 			server_redraw_window_borders(lastwp->window);
 			server_status_window(lastwp->window);
 		} else {
-			if (window_push_zoom(w, 0, args_has(args, 'Z')))
+			if (w->modal != NULL && lastwp != w->modal)
+				visible = 1;
+			else
+				visible = window_pane_is_visible(lastwp);
+			if (!visible && window_push_zoom(w, 0, Zflag))
 				server_redraw_window(w);
 			window_redraw_active_switch(w, lastwp);
 			if (window_set_active_pane(w, lastwp, 1)) {
 				cmd_find_from_winlink(current, wl, 0);
 				cmd_select_pane_redraw(w);
 			}
-			if (window_pop_zoom(w))
+			if (!visible && window_pop_zoom(w))
 				server_redraw_window(w);
 		}
 		return (CMD_RETURN_NORMAL);
@@ -268,14 +273,18 @@ cmd_select_pane_exec(struct cmd *self, struct cmdq_item *item)
 
 	if (wp == w->active)
 		return (CMD_RETURN_NORMAL);
-	if (window_push_zoom(w, 0, args_has(args, 'Z')))
+	if (w->modal != NULL && wp != w->modal)
+		visible = 1;
+	else
+		visible = window_pane_is_visible(wp);
+	if (!visible && window_push_zoom(w, 0, Zflag))
 		server_redraw_window(w);
 	window_redraw_active_switch(w, wp);
 	if (window_set_active_pane(w, wp, 1))
 		cmd_find_from_winlink_pane(current, wl, wp, 0);
 	cmdq_insert_hook(s, item, current, "after-select-pane");
 	cmd_select_pane_redraw(w);
-	if (window_pop_zoom(w))
+	if (!visible && window_pop_zoom(w))
 		server_redraw_window(w);
 
 	return (CMD_RETURN_NORMAL);

cmd-set-buffer.c

@@ -1,4 +1,4 @@
-/* $OpenBSD: cmd-set-buffer.c,v 1.37 2026/02/15 17:43:26 nicm Exp $ */
+/* $OpenBSD: cmd-set-buffer.c,v 1.38 2026/08/24 07:05:23 nicm Exp $ */
 
 /*
  * Copyright (c) 2007 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -100,6 +100,7 @@ cmd_set_buffer_exec(struct cmd *self, struct cmdq_item *item)
 			cmdq_error(item, "%s", cause);
 			goto fail;
 		}
+		free(bufname);
 		return (CMD_RETURN_NORMAL);
 	}
 
@@ -107,8 +108,10 @@ cmd_set_buffer_exec(struct cmd *self, struct cmdq_item *item)
 		cmdq_error(item, "no data specified");
 		goto fail;
 	}
-	if ((newsize = strlen(args_string(args, 0))) == 0)
+	if ((newsize = strlen(args_string(args, 0))) == 0) {
+		free(bufname);
 		return (CMD_RETURN_NORMAL);
+	}
 
 	if (args_has(args, 'a') && pb != NULL) {
 		olddata = paste_buffer_data(pb, &bufsize);
@@ -127,6 +130,7 @@ cmd_set_buffer_exec(struct cmd *self, struct cmdq_item *item)
 	if (args_has(args, 'w') && tc != NULL)
  		tty_set_selection(&tc->tty, "", bufdata, bufsize);
 
+	free(bufname);
 	return (CMD_RETURN_NORMAL);
 
 fail:

cmd-source-file.c

@@ -1,4 +1,4 @@
-/* $OpenBSD: cmd-source-file.c,v 1.62 2025/11/18 08:42:09 nicm Exp $ */
+/* $OpenBSD: cmd-source-file.c,v 1.63 2026/08/18 08:05:05 nicm Exp $ */
 
 /*
  * Copyright (c) 2008 Tiago Cunha <me@tiagocunha.org>
@@ -50,6 +50,7 @@ const struct cmd_entry cmd_source_file_entry = {
 
 struct cmd_source_file_data {
 	struct cmdq_item	 *item;
+	struct client		 *client;
 	int			  flags;
 
 	struct cmdq_item	 *after;
@@ -60,10 +61,24 @@ struct cmd_source_file_data {
 	u_int			  nfiles;
 };
 
-static enum cmd_retval
-cmd_source_file_complete_cb(struct cmdq_item *item, __unused void *data)
+static void
+cmd_source_file_free_data(struct cmd_source_file_data *cdata)
 {
-	struct client	*c = cmdq_get_client(item);
+	u_int	i;
+
+	for (i = 0; i < cdata->nfiles; i++)
+		free(cdata->files[i]);
+	free(cdata->files);
+	if (cdata->client != NULL)
+		server_client_unref(cdata->client);
+	free(cdata);
+}
+
+static enum cmd_retval
+cmd_source_file_complete_cb(struct cmdq_item *item, void *data)
+{
+	struct cmd_source_file_data	*cdata = data;
+	struct client			*c = cdata->client;
 
 	if (c == NULL) {
 		cmd_source_file_depth--;
@@ -74,36 +89,36 @@ cmd_source_file_complete_cb(struct cmdq_item *item, __unused void *data)
 	}
 
 	cfg_print_causes(item);
+	cmd_source_file_free_data(cdata);
 	return (CMD_RETURN_NORMAL);
 }
 
 static void
-cmd_source_file_complete(struct client *c, struct cmd_source_file_data *cdata)
+cmd_source_file_complete(struct cmd_source_file_data *cdata)
 {
+	struct client		*c = cdata->client;
 	struct cmdq_item	*new_item;
-	u_int			 i;
 
-	if (cfg_finished) {
-		if (cdata->retval == CMD_RETURN_ERROR &&
-		    c != NULL &&
-		    c->session == NULL)
-			c->retval = 1;
-		new_item = cmdq_get_callback(cmd_source_file_complete_cb, NULL);
-		cmdq_insert_after(cdata->after, new_item);
+	if (!cfg_finished) {
+		cmd_source_file_free_data(cdata);
+		return;
 	}
 
-	for (i = 0; i < cdata->nfiles; i++)
-		free(cdata->files[i]);
-	free(cdata->files);
-	free(cdata);
+	if (cdata->retval == CMD_RETURN_ERROR &&
+	    c != NULL &&
+	    c->session == NULL)
+		c->retval = 1;
+	new_item = cmdq_get_callback(cmd_source_file_complete_cb, cdata);
+	cmdq_insert_after(cdata->after, new_item);
 }
 
 static void
-cmd_source_file_done(struct client *c, const char *path, int error,
-    int closed, struct evbuffer *buffer, void *data)
+cmd_source_file_done(__unused struct client *oc, const char *path,
+    int error, int closed, struct evbuffer *buffer, void *data)
 {
 	struct cmd_source_file_data	*cdata = data;
 	struct cmdq_item		*item = cdata->item;
+	struct client			*c = cdata->client;
 	void				*bdata = EVBUFFER_DATA(buffer);
 	size_t				 bsize = EVBUFFER_LENGTH(buffer);
 	u_int				 n;
@@ -127,7 +142,7 @@ cmd_source_file_done(struct client *c, const char *path, int error,
 	if (n < cdata->nfiles)
 		file_read(c, cdata->files[n], cmd_source_file_done, cdata);
 	else {
-		cmd_source_file_complete(c, cdata);
+		cmd_source_file_complete(cdata);
 		cmdq_continue(item);
 	}
 }
@@ -187,6 +202,9 @@ cmd_source_file_exec(struct cmd *self, struct cmdq_item *item)
 
 	cdata = xcalloc(1, sizeof *cdata);
 	cdata->item = item;
+	cdata->client = c;
+	if (c != NULL)
+		c->references++;
 
 	if (args_has(args, 'q'))
 		cdata->flags |= CMD_PARSE_QUIET;
@@ -249,7 +267,7 @@ cmd_source_file_exec(struct cmd *self, struct cmdq_item *item)
 		file_read(c, cdata->files[0], cmd_source_file_done, cdata);
 		retval = CMD_RETURN_WAIT;
 	} else
-		cmd_source_file_complete(c, cdata);
+		cmd_source_file_complete(cdata);
 
 	free(cwd);
 	return (retval);

cmd-split-window.c

@@ -1,4 +1,4 @@
-/* $OpenBSD: cmd-split-window.c,v 1.148 2026/08/07 08:10:53 nicm Exp $ */
+/* $OpenBSD: cmd-split-window.c,v 1.151 2026/09/10 11:02:18 nicm Exp $ */
 
 /*
  * Copyright (c) 2009 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -40,8 +40,8 @@ const struct cmd_entry cmd_new_pane_entry = {
 	.name = "new-pane",
 	.alias = "newp",
 
-	.args = { "bB:Cc:de:EfF:hIkl:LMm:Op:PR:s:S:t:T:vWx:X:y:Y:Z", 0, -1, NULL },
-	.usage = "[-bCdefhIklMOPvWZ] [-B border-lines] "
+	.args = { "AbB:Cc:Dde:EfF:hIkl:KLMm:Op:PR:s:S:t:T:vWx:X:y:Y:Z", 0, -1, NULL },
+	.usage = "[-AbCDefhIkKLMOPvWZ] [-B border-lines] "
 		 "[-c start-directory] [-e environment] "
 		 "[-F format] [-l size] [-m message] [-p percentage] "
 		 "[-s style] [-S active-border-style] "
@@ -89,6 +89,7 @@ cmd_split_window_exec(struct cmd *self, struct cmdq_item *item)
 	struct cmd_find_state	 fs;
 	struct key_event	*event = cmdq_get_event(item);
 	int			 input, empty, is_floating, flags = 0;
+	int			 restore_zoom = 0;
 	const char		*template, *style, *value;
 	char			*cause = NULL, *cp, *title;
 	const struct options_table_entry *oe;
@@ -96,10 +97,16 @@ cmd_split_window_exec(struct cmd *self, struct cmdq_item *item)
 	enum pane_lines		 lines;
 	u_int			 count = args_count(args);
 
+	if (window_active_pane_is_over_zoom(w))
+		restore_zoom = 1;
+
 	if (cmd_get_entry(self) == &cmd_new_pane_entry)
 		is_floating = !args_has(args, 'L');
 	else {
-		window_unzoom(w, 1);
+		if (!window_pane_is_visible(wp))
+			restore_zoom = 0;
+		if (!restore_zoom)
+			window_unzoom(w, 1);
 		is_floating = window_pane_is_floating(wp);
 		flags |= SPAWN_SPLIT;
 	}
@@ -133,7 +140,11 @@ cmd_split_window_exec(struct cmd *self, struct cmdq_item *item)
 	if (args_has(args, 'Z'))
 		flags |= SPAWN_ZOOM;
 	if (args_has(args, 'O'))
-		flags |= SPAWN_MODAL;
+		flags |= SPAWN_MODAL|SPAWN_FLOATOVERZOOM;
+	if (is_floating && args_has(args, 'A'))
+		flags |= SPAWN_FLOATOVERZOOM;
+	if ((w->flags & WINDOW_ZOOMED) && (flags & SPAWN_FLOATOVERZOOM))
+		restore_zoom = 1;
 
 	input = args_has(args, 'I');
 	if (input || (count == 1 && *args_string(args, 0) == '\0'))
@@ -169,6 +180,8 @@ cmd_split_window_exec(struct cmd *self, struct cmdq_item *item)
 	if (cause != NULL) {
 		cmdq_error(item, "%s", cause);
 		free(cause);
+		if (restore_zoom)
+			window_pop_zoom(w);
 		return (CMD_RETURN_ERROR);
 	}
 
@@ -202,8 +215,12 @@ cmd_split_window_exec(struct cmd *self, struct cmdq_item *item)
 		 */
 		goto fail;
 	}
+	if (args_has(args, 'K') && args_has(args, 'O'))
+		new_wp->flags |= PANE_CAPTUREALLKEYS;
 	if (args_has(args, 'C') && args_has(args, 'O'))
 		new_wp->flags |= PANE_CLOSEONCLICK;
+	if (args_has(args, 'D') && args_has(args, 'O'))
+		new_wp->flags |= PANE_CLOSEONCANCEL;
 
 	style = args_get(args, 's');
 	if (style != NULL) {
@@ -271,7 +288,10 @@ cmd_split_window_exec(struct cmd *self, struct cmdq_item *item)
 	if (~flags & SPAWN_DETACHED)
 		cmd_find_from_winlink_pane(current, wl, new_wp, 0);
 
-	if ((~flags & SPAWN_FLOATING) && !args_has(args, 'O')) {
+	if (restore_zoom) {
+		window_pop_zoom(wp->window);
+		server_redraw_window(wp->window);
+	} else if ((~flags & SPAWN_FLOATING) && !args_has(args, 'O')) {
 		window_pop_zoom(wp->window);
 		server_redraw_window(wp->window);
 	}
@@ -322,8 +342,9 @@ fail:
 		if (!is_floating)
 			layout_close_pane(new_wp);
 		window_remove_pane(wp->window, new_wp);
-	} else if (args_has(args, 'O'))
-		window_pop_modal_zoom(wp->window);
+	}
+	if (restore_zoom || (~flags & SPAWN_FLOATING))
+		window_pop_zoom(wp->window);
 	if (sc.argv != NULL)
 		cmd_free_argv(sc.argc, sc.argv);
 	environ_free(sc.environ);

cmd-switch-client.c

@@ -1,4 +1,4 @@
-/* $OpenBSD: cmd-switch-client.c,v 1.74 2026/05/22 15:22:43 nicm Exp $ */
+/* $OpenBSD: cmd-switch-client.c,v 1.75 2026/08/20 09:19:24 nicm Exp $ */
 
 /*
  * Copyright (c) 2007 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -53,7 +53,7 @@ cmd_switch_client_exec(struct cmd *self, struct cmdq_item *item)
 	struct cmd_find_state	 target;
 	const char		*tflag = args_get(args, 't');
 	enum cmd_find_type	 type;
-	int			 flags;
+	int			 flags, visible, Zflag = args_has(args, 'Z');
 	struct client		*c = cmdq_get_client(item);
 	struct client		*tc = cmdq_get_target_client(item);
 	struct session		*s;
@@ -139,11 +139,15 @@ cmd_switch_client_exec(struct cmd *self, struct cmdq_item *item)
 			return (CMD_RETURN_NORMAL);
 		if (wl != NULL && wp != NULL && wp != wl->window->active) {
 			w = wl->window;
-			if (window_push_zoom(w, 0, args_has(args, 'Z')))
+			if (w->modal != NULL && wp != w->modal)
+				visible = 1;
+			else
+				visible = window_pane_is_visible(wp);
+			if (!visible && window_push_zoom(w, 0, Zflag))
 				server_redraw_window(w);
 			window_redraw_active_switch(w, wp);
 			window_set_active_pane(w, wp, 1);
-			if (window_pop_zoom(w))
+			if (!visible && window_pop_zoom(w))
 				server_redraw_window(w);
 		}
 		if (wl != NULL) {

configure.ac

@@ -1,6 +1,6 @@
 # configure.ac
 
-AC_INIT([tmux], next-3.8)
+AC_INIT([tmux], next-3.9)
 AC_PREREQ([2.60])
 
 AC_CONFIG_AUX_DIR(etc)
@@ -530,34 +530,15 @@ if test "x$enable_cgroups" = xyes; then
 	fi
 fi
 
-# Enable image support.
-AC_ARG_ENABLE(
-	images,
-	AS_HELP_STRING(--enable-images, enable Kitty/SIXEL/ASCII images)
-)
-
-# Keep the old option as an alias for one compatibility cycle.
+# Enable sixel support.
 AC_ARG_ENABLE(
 	sixel,
-	AS_HELP_STRING(--enable-sixel, deprecated alias for --enable-images)
+	AS_HELP_STRING(--enable-sixel, enable sixel images)
 )
 if test "x$enable_sixel" = xyes; then
-	enable_images=yes
+	AC_DEFINE(ENABLE_SIXEL)
 fi
-if test "x$enable_images" = xyes; then
-	PKG_CHECK_MODULES(
-		IMAGE,
-		[libpng >= 1.6 zlib],
-		[
-			AM_CPPFLAGS="$IMAGE_CFLAGS $AM_CPPFLAGS"
-			CPPFLAGS="$AM_CPPFLAGS $SAVED_CPPFLAGS"
-			LIBS="$IMAGE_LIBS $LIBS"
-		],
-		AC_MSG_ERROR("image support requires libpng 1.6 and zlib")
-	)
-	AC_DEFINE(ENABLE_IMAGES)
-fi
-AM_CONDITIONAL(ENABLE_IMAGES, [test "x$enable_images" = xyes])
+AM_CONDITIONAL(ENABLE_SIXEL, [test "x$enable_sixel" = xyes])
 
 # Check for b64_ntop. If we have b64_ntop, we assume b64_pton as well.
 AC_MSG_CHECKING(for b64_ntop)
@@ -1156,10 +1137,10 @@ if test "x$enable_asan" = xyes; then
 else
 	AC_MSG_NOTICE([ASAN: off])
 fi
-if test "x$enable_images" = xyes; then
-	AC_MSG_NOTICE([images: on])
+if test "x$enable_sixel" = xyes; then
+	AC_MSG_NOTICE([SIXEL: on])
 else
-	AC_MSG_NOTICE([images: off])
+	AC_MSG_NOTICE([SIXEL: off])
 fi
 if test "x$enable_debug" = xyes; then
 	AC_MSG_NOTICE([debug: on])

control-notify.c

@@ -1,4 +1,4 @@
-/* $OpenBSD: control-notify.c,v 1.38 2026/08/03 13:38:42 nicm Exp $ */
+/* $OpenBSD: control-notify.c,v 1.39 2026/09/08 10:20:08 nicm Exp $ */
 
 /*
  * Copyright (c) 2012 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -70,6 +70,7 @@ control_window_layout_changed_cb(__unused const char *name,
 	struct session		*s;
 	struct winlink		*wl;
 	struct window		*w = event_payload_get_window(ep, "window");
+	struct format_tree	*ft;
 	const char		*template;
 	char			*cp;
 
@@ -84,19 +85,25 @@ control_window_layout_changed_cb(__unused const char *name,
 	 * and we don't need to inform the client about the layout change
 	 * because the whole window will go away soon.
 	 */
-	wl = TAILQ_FIRST(&w->winlinks);
-	if (wl == NULL || w->layout_root == NULL)
+	if (TAILQ_FIRST(&w->winlinks) == NULL || w->layout_root == NULL)
 		return;
-	cp = format_single(NULL, template, NULL, NULL, wl, NULL);
 
 	TAILQ_FOREACH(c, &clients, entry) {
 		if (!CONTROL_SHOULD_NOTIFY_CLIENT(c) || c->session == NULL)
 			continue;
 		s = c->session;
-		if (winlink_find_by_window_id(&s->windows, w->id) != NULL)
-			control_notify_write(c, "%s", cp);
+		wl = winlink_find_by_window_id(&s->windows, w->id);
+		if (wl == NULL)
+			continue;
+
+		ft = format_create(c, NULL, FORMAT_NONE, 0);
+		format_defaults(ft, c, s, wl, NULL);
+		cp = format_expand(ft, template);
+		format_free(ft);
+
+		control_notify_write(c, "%s", cp);
+		free(cp);
 	}
-	free(cp);
 }
 
 /* Notify control clients that window pane changed. */

control.c

@@ -1,4 +1,4 @@
-/* $OpenBSD: control.c,v 1.65 2026/08/04 11:18:22 nicm Exp $ */
+/* $OpenBSD: control.c,v 1.68 2026/09/09 08:30:05 nicm Exp $ */
 
 /*
  * Copyright (c) 2012 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -108,6 +108,7 @@ struct control_state {
 	u_int				 pending_count;
 
 	TAILQ_HEAD(, control_block)	 all_blocks;
+	size_t				 queued_reply_bytes;
 
 	struct bufferevent		*read_event;
 	struct bufferevent		*write_event;
@@ -132,6 +133,9 @@ struct control_state {
 /* Maximum age for clients that are not using pause mode. */
 #define CONTROL_MAXIMUM_AGE 300000
 
+/* Maximum buffered command replies for a client that is not reading. */
+#define CONTROL_MAXIMUM_REPLY_BUFFER (64 * 1024 * 1024)
+
 /* Flags to ignore client. */
 #define CONTROL_IGNORE_FLAGS \
 	(CLIENT_CONTROL_NOOUTPUT| \
@@ -165,6 +169,15 @@ RB_GENERATE_STATIC(control_windows, control_window, entry, control_window_cmp);
 static void
 control_free_block(struct control_state *cs, struct control_block *cb)
 {
+	size_t	 size;
+
+	if (cb->size == 0 && cb->line != NULL) {
+		size = strlen(cb->line) + 1;
+		if (cs->queued_reply_bytes > size)
+			cs->queued_reply_bytes -= size;
+		else
+			cs->queued_reply_bytes = 0;
+	}
 	free(cb->line);
 	TAILQ_REMOVE(&cs->all_blocks, cb, all_entry);
 	free(cb);
@@ -388,16 +401,71 @@ control_pause_pane(struct client *c, struct window_pane *wp)
 	}
 }
 
+/*
+ * Reset a pane after its buffer has been replaced: drop any output still
+ * queued from the old buffer and start again from the pane's own offset.
+ */
+void
+control_reset_pane(struct client *c, struct window_pane *wp)
+{
+	struct control_pane	*cp;
+
+	if (c->control_state == NULL)
+		return;
+	cp = control_get_pane(c, wp);
+	if (cp == NULL)
+		return;
+	control_discard_pane(c, cp);
+	memcpy(&cp->offset, &wp->offset, sizeof cp->offset);
+	memcpy(&cp->queued, &wp->offset, sizeof cp->queued);
+}
+
+/*
+ * Check if the replies buffered for a client, including one about to be
+ * added, have grown too large and kill it if so. Returns 1 if further output
+ * for the client should be dropped.
+ */
+static int
+control_check_reply_buffer(struct client *c, size_t added)
+{
+	struct control_state	*cs = c->control_state;
+	size_t			 size;
+
+	if (c->flags & CLIENT_CONTROL_DISCARD)
+		return (1);
+	size = EVBUFFER_LENGTH(cs->write_event->output);
+	size += cs->queued_reply_bytes;
+	size += added;
+	if (size < CONTROL_MAXIMUM_REPLY_BUFFER)
+		return (0);
+
+	log_debug("%s: %s: %zu bytes of replies buffered", __func__, c->name,
+	    size);
+	if (~c->flags & CLIENT_EXIT) {
+		c->exit_message = xstrdup("too far behind");
+		c->flags |= CLIENT_EXIT;
+		control_discard(c);
+	}
+	c->flags |= CLIENT_CONTROL_DISCARD;
+	return (1);
+}
+
 /* Write an already-formatted line, queueing it behind %output if needed. */
 static void
 control_write_line(struct client *c, char *line)
 {
 	struct control_state	*cs = c->control_state;
 	struct control_block	*cb;
+	size_t			 size = strlen(line) + 1;
+
+	if (control_check_reply_buffer(c, size)) {
+		free(line);
+		return;
+	}
 
 	if (TAILQ_EMPTY(&cs->all_blocks)) {
 		log_debug("%s: %s: writing line: %s", __func__, c->name, line);
-		bufferevent_write(cs->write_event, line, strlen(line));
+		bufferevent_write(cs->write_event, line, size - 1);
 		bufferevent_write(cs->write_event, "\n", 1);
 		bufferevent_enable(cs->write_event, EV_WRITE);
 		free(line);
@@ -407,6 +475,7 @@ control_write_line(struct client *c, char *line)
 	cb = xcalloc(1, sizeof *cb);
 	cb->line = line;
 	TAILQ_INSERT_TAIL(&cs->all_blocks, cb, all_entry);
+	cs->queued_reply_bytes += size;
 	cb->t = get_timer();
 
 	log_debug("%s: %s: storing line: %s", __func__, c->name, cb->line);
@@ -436,8 +505,12 @@ control_flush_deferred(struct client *c)
 void
 control_write(struct client *c, const char *fmt, ...)
 {
-	va_list	 ap;
-	char	*line;
+	struct control_state	*cs = c->control_state;
+	char			*line;
+	va_list			 ap;
+
+	if (cs == NULL)
+		return;
 
 	va_start(ap, fmt);
 	xvasprintf(&line, fmt, ap);
@@ -460,6 +533,9 @@ control_write_guard(struct client *c, const char *guard, long t, u_int number,
 	struct control_state	*cs = c->control_state;
 	char			*line;
 
+	if (cs == NULL)
+		return;
+
 	if (strcmp(guard, "begin") == 0)
 		cs->guard_depth++;
 
@@ -484,6 +560,9 @@ control_notify_write(struct client *c, const char *fmt, ...)
 	va_list			 ap;
 	char			*line;
 
+	if (cs == NULL)
+		return;
+
 	va_start(ap, fmt);
 	xvasprintf(&line, fmt, ap);
 	va_end(ap);
@@ -978,6 +1057,7 @@ control_discard_all(struct client *c)
 	control_discard(c);
 	TAILQ_FOREACH_SAFE(cb, &cs->all_blocks, all_entry, cb1)
 		control_free_block(cs, cb);
+	cs->queued_reply_bytes = 0;
 	bufferevent_disable(cs->write_event, EV_WRITE);
 }
 

format.c

@@ -1,4 +1,4 @@
-/* $OpenBSD: format.c,v 1.412 2026/08/05 07:31:08 nicm Exp $ */
+/* $OpenBSD: format.c,v 1.417 2026/09/08 15:42:26 nicm Exp $ */
 
 /*
  * Copyright (c) 2011 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -855,26 +855,42 @@ format_cb_window_active_clients_list(struct format_tree *ft)
 static void *
 format_cb_window_layout(struct format_tree *ft)
 {
-	struct window	*w = ft->w;
+	struct client		*c = ft->client;
+	struct window		*w = ft->w;
+	struct layout_cell	*lcroot;
+	int			 flags = 0;
 
 	if (w == NULL)
 		return (NULL);
 
 	if (w->saved_layout_root != NULL)
-		return (layout_dump(w, w->saved_layout_root));
-	return (layout_dump(w, w->layout_root));
+		lcroot = w->saved_layout_root;
+	else
+		lcroot = w->layout_root;
+
+	if (c != NULL &&
+	    (c->flags & CLIENT_CONTROL) &&
+	    (~c->flags & CLIENT_CONTROL_NEWLAYOUTS))
+		flags |= LAYOUT_CUSTOM_OLD_FORMAT;
+	return (layout_dump(w, lcroot, flags));
 }
 
 /* Callback for window_visible_layout. */
 static void *
 format_cb_window_visible_layout(struct format_tree *ft)
 {
+	struct client	*c = ft->client;
 	struct window	*w = ft->w;
+	int		 flags = 0;
 
 	if (w == NULL)
 		return (NULL);
 
-	return (layout_dump(w, w->layout_root));
+	if (c != NULL &&
+	    (c->flags & CLIENT_CONTROL) &&
+	    (~c->flags & CLIENT_CONTROL_NEWLAYOUTS))
+		flags |= LAYOUT_CUSTOM_OLD_FORMAT;
+	return (layout_dump(w, w->layout_root, flags));
 }
 
 /* Callback for pane_start_command. */
@@ -1887,6 +1903,37 @@ format_cb_cursor_blinking(struct format_tree *ft)
 	return (NULL);
 }
 
+/* Callback for history_added. */
+static void *
+format_cb_history_added(struct format_tree *ft)
+{
+	if (ft->wp != NULL)
+		return (format_printf("%u", ft->wp->base.grid->scroll_added));
+	return (NULL);
+}
+
+/* Callback for history_collected. */
+static void *
+format_cb_history_collected(struct format_tree *ft)
+{
+	struct window_pane	*wp = ft->wp;
+
+	if (wp != NULL)
+		return (format_printf("%u", wp->base.grid->scroll_collected));
+	return (NULL);
+}
+
+/* Callback for history_generation. */
+static void *
+format_cb_history_generation(struct format_tree *ft)
+{
+	struct window_pane	*wp = ft->wp;
+
+	if (wp != NULL)
+		return (format_printf("%u", wp->base.grid->scroll_generation));
+	return (NULL);
+}
+
 /* Callback for history_limit. */
 static void *
 format_cb_history_limit(struct format_tree *ft)
@@ -2276,6 +2323,19 @@ format_cb_pane_last_output_time(struct format_tree *ft)
 	return (NULL);
 }
 
+/* Callback for pane_output_generation. */
+static void *
+format_cb_pane_output_generation(struct format_tree *ft)
+{
+	unsigned long long	 value;
+
+	if (ft->wp != NULL) {
+		value = ft->wp->output_generation;
+		return (format_printf("%llu", value));
+	}
+	return (NULL);
+}
+
 /* Callback for pane_last_prompt_time. */
 static void *
 format_cb_pane_last_prompt_time(struct format_tree *ft)
@@ -3018,17 +3078,6 @@ format_cb_sixel_support(__unused struct format_tree *ft)
 #endif
 }
 
-/* Callback for image_support. */
-static void *
-format_cb_image_support(__unused struct format_tree *ft)
-{
-#ifdef ENABLE_IMAGES
-	return (xstrdup("1"));
-#else
-	return (xstrdup("0"));
-#endif
-}
-
 /* Callback for active_window_index. */
 static void *
 format_cb_active_window_index(struct format_tree *ft)
@@ -3674,12 +3723,21 @@ static const struct format_table_entry format_table[] = {
 	{ "cursor_y", FORMAT_TABLE_STRING,
 	  format_cb_cursor_y
 	},
+	{ "history_added", FORMAT_TABLE_STRING,
+	  format_cb_history_added
+	},
 	{ "history_all_bytes", FORMAT_TABLE_STRING,
 	  format_cb_history_all_bytes
 	},
 	{ "history_bytes", FORMAT_TABLE_STRING,
 	  format_cb_history_bytes
 	},
+	{ "history_collected", FORMAT_TABLE_STRING,
+	  format_cb_history_collected
+	},
+	{ "history_generation", FORMAT_TABLE_STRING,
+	  format_cb_history_generation
+	},
 	{ "history_limit", FORMAT_TABLE_STRING,
 	  format_cb_history_limit
 	},
@@ -3692,9 +3750,6 @@ static const struct format_table_entry format_table[] = {
 	{ "host_short", FORMAT_TABLE_STRING,
 	  format_cb_host_short
 	},
-	{ "image_support", FORMAT_TABLE_STRING,
-	  format_cb_image_support
-	},
 	{ "insert_flag", FORMAT_TABLE_STRING,
 	  format_cb_insert_flag
 	},
@@ -3863,6 +3918,9 @@ static const struct format_table_entry format_table[] = {
 	{ "pane_mode", FORMAT_TABLE_STRING,
 	  format_cb_pane_mode
 	},
+	{ "pane_output_generation", FORMAT_TABLE_STRING,
+	  format_cb_pane_output_generation
+	},
 	{ "pane_path", FORMAT_TABLE_STRING,
 	  format_cb_pane_path
 	},
@@ -4401,7 +4459,7 @@ format_quote_shell(const char *s)
 
 	at = out = xmalloc(strlen(s) * 2 + 1);
 	for (cp = s; *cp != '\0'; cp++) {
-		if (strchr("|&;<>()$`\\\"'*?[# =%\n\t", *cp) != NULL)
+		if (strchr("|&;<>(){}$`\\\"'*?[# =%\n\t", *cp) != NULL)
 			*at++ = '\\';
 		*at++ = *cp;
 	}
@@ -5192,6 +5250,7 @@ format_loop_sessions(struct format_expand_state *es, const char *fmt)
 		format_log(es, "session loop: $%u", s->id);
 		if (active != NULL &&
 		    ft->c != NULL &&
+		    ft->c->session != NULL &&
 		    s->id == ft->c->session->id)
 			use = active;
 		else

grid.c

@@ -1,4 +1,4 @@
-/* $OpenBSD: grid.c,v 1.156 2026/08/03 12:58:53 nicm Exp $ */
+/* $OpenBSD: grid.c,v 1.158 2026/09/01 12:49:49 nicm Exp $ */
 
 /*
  * Copyright (c) 2008 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -86,9 +86,6 @@ grid_check_is_clear(struct grid *gd)
 		assert(gl->extdsize == 0);
 		assert(gl->flags == 0);
 		assert(gl->time == 0);
-#ifdef ENABLE_IMAGES
-		assert(gl->images == NULL);
-#endif
 	}
 }
 #else
@@ -356,9 +353,6 @@ grid_free_line(struct grid *gd, u_int py)
 	assert(gl->cellsize == 0 || gl->celldata != NULL);
 #endif
 
-#ifdef ENABLE_IMAGES
-	image_grid_free_line(gd, gl);
-#endif
 	free(gl->celldata);
 	free(gl->extddata);
 	memset(gl, 0, sizeof *gl);
@@ -403,9 +397,6 @@ void
 grid_destroy(struct grid *gd)
 {
 	grid_free_lines(gd, 0, gd->hsize + gd->sy);
-#ifdef ENABLE_IMAGES
-	image_grid_free(gd);
-#endif
 	free(gd->linedata);
 	free(gd);
 }
@@ -738,9 +729,6 @@ grid_clear(struct grid *gd, u_int px, u_int py, u_int nx, u_int ny, u_int bg)
 
 	if (nx == 0 || ny == 0)
 		return;
-#ifdef ENABLE_IMAGES
-	image_grid_damage(gd, px, py, nx, ny);
-#endif
 
 	if (px == 0 && nx == gd->sx) {
 		grid_clear_lines(gd, py, ny, bg);
@@ -776,10 +764,6 @@ grid_clear(struct grid *gd, u_int px, u_int py, u_int nx, u_int ny, u_int bg)
 void
 grid_clear_lines(struct grid *gd, u_int py, u_int ny, u_int bg)
 {
-	struct grid_line	*gl;
-#ifdef ENABLE_IMAGES
-	struct image_line	*images;
-#endif
 	u_int	yy;
 
 	if (ny == 0)
@@ -791,18 +775,8 @@ grid_clear_lines(struct grid *gd, u_int py, u_int ny, u_int bg)
 		return;
 
 	for (yy = py; yy < py + ny; yy++) {
-		gl = &gd->linedata[yy];
-#ifdef ENABLE_IMAGES
-		image_grid_damage(gd, 0, yy, gd->sx, 1);
-		images = gl->images;
-#endif
-		free(gl->celldata);
-		free(gl->extddata);
-		memset(gl, 0, sizeof *gl);
+		grid_free_line(gd, yy);
 		grid_empty_line(gd, yy, bg);
-#ifdef ENABLE_IMAGES
-		gl->images = images;
-#endif
 	}
 	if (py != 0)
 		gd->linedata[py - 1].flags &= ~GRID_LINE_WRAPPED;
@@ -867,9 +841,6 @@ grid_move_cells(struct grid *gd, u_int dx, u_int px, u_int py, u_int nx,
 
 	grid_expand_line(gd, py, px + nx, 8);
 	grid_expand_line(gd, py, dx + nx, 8);
-#ifdef ENABLE_IMAGES
-	image_grid_move_cells(gd, dx, px, py, nx);
-#endif
 	memmove(&gl->celldata[dx], &gl->celldata[px],
 	    nx * sizeof *gl->celldata);
 	if (dx + nx > gl->cellused)
@@ -1242,6 +1213,7 @@ grid_string_cells(struct grid *gd, u_int px, u_int py, u_int nx,
 		grid_get_cell(gd, xx, py, &gc);
 		if (gc.flags & GRID_FLAG_PADDING)
 			continue;
+
 		if (lastgc != NULL && (flags & GRID_STRING_WITH_SEQUENCES)) {
 			grid_string_cells_code(*lastgc, &gc, code, sizeof code,
 			    flags, s, &has_link);
@@ -1308,18 +1280,11 @@ grid_duplicate_lines(struct grid *dst, u_int dy, struct grid *src, u_int sy,
 {
 	struct grid_line	*dstl, *srcl;
 	u_int			 yy;
-#ifdef ENABLE_IMAGES
-	u_int			 original_dy, original_sy;
-#endif
 
 	if (dy + ny > dst->hsize + dst->sy)
 		ny = dst->hsize + dst->sy - dy;
 	if (sy + ny > src->hsize + src->sy)
 		ny = src->hsize + src->sy - sy;
-#ifdef ENABLE_IMAGES
-	original_dy = dy;
-	original_sy = sy;
-#endif
 	grid_free_lines(dst, dy, ny);
 
 	for (yy = 0; yy < ny; yy++) {
@@ -1327,9 +1292,6 @@ grid_duplicate_lines(struct grid *dst, u_int dy, struct grid *src, u_int sy,
 		dstl = &dst->linedata[dy];
 
 		memcpy(dstl, srcl, sizeof *dstl);
-#ifdef ENABLE_IMAGES
-		dstl->images = NULL;
-#endif
 		if (srcl->cellsize != 0) {
 			dstl->celldata = xreallocarray(NULL,
 			    srcl->cellsize, sizeof *dstl->celldata);
@@ -1349,9 +1311,6 @@ grid_duplicate_lines(struct grid *dst, u_int dy, struct grid *src, u_int sy,
 		sy++;
 		dy++;
 	}
-#ifdef ENABLE_IMAGES
-	image_grid_duplicate_lines(dst, original_dy, src, original_sy, ny);
-#endif
 }
 
 /* Mark line as dead. */
@@ -1362,30 +1321,6 @@ grid_reflow_dead(struct grid_line *gl)
 	gl->flags = GRID_LINE_DEAD;
 }
 
-/* Image rows are cell-aligned and must not be reflowed like text. */
-static int
-grid_reflow_has_image(struct grid_line *gl)
-{
-	struct grid_cell	 gc;
-	u_int			 i;
-
-#ifdef ENABLE_IMAGES
-	if (image_grid_line_has_images(gl))
-		return (1);
-#endif
-	if (~gl->flags & GRID_LINE_EXTENDED)
-		return (0);
-	for (i = 0; i < gl->cellused; i++) {
-		grid_get_cell1(gl, i, &gc);
-		/* Kitty Unicode placeholder base character (U+10EEEE). */
-		if (gc.data.size >= 4 && gc.data.data[0] == 0xf4 &&
-		    gc.data.data[1] == 0x8e && gc.data.data[2] == 0xbb &&
-		    gc.data.data[3] == 0xae)
-			return (1);
-	}
-	return (0);
-}
-
 /* Add lines, return the first new one. */
 static struct grid_line *
 grid_reflow_add(struct grid *gd, u_int n)
@@ -1448,10 +1383,6 @@ grid_reflow_join(struct grid *target, struct grid *gd, u_int sx, u_int yy,
 			break;
 		line = yy + 1 + lines;
 
-		/* Do not join wrapped text to a cell-aligned image row. */
-		if (grid_reflow_has_image(&gd->linedata[line]))
-			break;
-
 		/* If the next line is empty, skip it. */
 		if (~gd->linedata[line].flags & GRID_LINE_WRAPPED)
 			wrapped = 0;
@@ -1512,7 +1443,8 @@ grid_reflow_join(struct grid *target, struct grid *gd, u_int sx, u_int yy,
 
 	/* Remove the lines that were completely consumed. */
 	for (i = yy + 1; i < yy + 1 + lines; i++) {
-		grid_free_line(gd, i);
+		free(gd->linedata[i].celldata);
+		free(gd->linedata[i].extddata);
 		grid_reflow_dead(&gd->linedata[i]);
 	}
 
@@ -1614,12 +1546,6 @@ grid_reflow(struct grid *gd, u_int sx)
 		if (gl->flags & GRID_LINE_DEAD)
 			continue;
 
-		/* Keep image layers at their original cell coordinates. */
-		if (grid_reflow_has_image(gl)) {
-			grid_reflow_move(target, gl);
-			continue;
-		}
-
 		/*
 		 * Work out the width of this line. at is the point at which
 		 * the available width is hit, and width is the full line
@@ -1709,7 +1635,7 @@ grid_wrap_position(struct grid *gd, u_int px, u_int py, u_int *wx, u_int *wy)
 void
 grid_unwrap_position(struct grid *gd, u_int *px, u_int *py, u_int wx, u_int wy)
 {
-	u_int	yy, ay = 0;
+	u_int	yy, ay = 0, ey = gd->hsize + gd->sy - 1;
 
 	for (yy = 0; yy < gd->hsize + gd->sy - 1; yy++) {
 		if (ay == wy)
@@ -1723,7 +1649,7 @@ grid_unwrap_position(struct grid *gd, u_int *px, u_int *py, u_int wx, u_int wy)
 	 * until we find the end or the line now containing wx.
 	 */
 	if (wx == UINT_MAX) {
-		while (gd->linedata[yy].flags & GRID_LINE_WRAPPED)
+		while (yy < ey && gd->linedata[yy].flags & GRID_LINE_WRAPPED)
 			yy++;
 		wx = gd->linedata[yy].cellused;
 	} else {
@@ -1785,21 +1711,29 @@ grid_in_set(struct grid *gd, u_int px, u_int py, const char *set)
 {
 	struct grid_cell	gc, tmp_gc;
 	u_int			pxx;
+	int			has_tab, has_space;
+
+	has_tab = (strchr(set, '\t') != NULL);
+	has_space = (strchr(set, ' ') != NULL);
 
 	grid_get_cell(gd, px, py, &gc);
-	if (strchr(set, '\t')) {
-		if (gc.flags & GRID_FLAG_PADDING) {
-			pxx = px;
-			do
-				grid_get_cell(gd, --pxx, py, &tmp_gc);
-			while (pxx > 0 && tmp_gc.flags & GRID_FLAG_PADDING);
-			if (tmp_gc.flags & GRID_FLAG_TAB)
-				return (tmp_gc.data.width - (px - pxx));
-		} else if (gc.flags & GRID_FLAG_TAB)
-			return (gc.data.width);
-	}
-	if (gc.flags & GRID_FLAG_PADDING)
+	if (gc.flags & GRID_FLAG_PADDING) {
+		if (!has_tab && !has_space)
+			return (0);
+		pxx = px;
+		do
+			grid_get_cell(gd, --pxx, py, &tmp_gc);
+		while (pxx > 0 && tmp_gc.flags & GRID_FLAG_PADDING);
+		if (((has_tab || has_space) &&
+		    (tmp_gc.flags & GRID_FLAG_TAB)) ||
+		    (has_space && utf8_has_whitespace(&tmp_gc.data)))
+			return (tmp_gc.data.width - (px - pxx));
 		return (0);
+	}
+	if ((has_tab || has_space) && (gc.flags & GRID_FLAG_TAB))
+		return (gc.data.width);
+	if (has_space && utf8_has_whitespace(&gc.data))
+		return (gc.data.width == 0 ? 1 : gc.data.width);
 	return (utf8_cstrhas(set, &gc.data));
 }
 

input.c

@@ -1,4 +1,4 @@
-/* $OpenBSD: input.c,v 1.269 2026/07/20 11:16:33 nicm Exp $ */
+/* $OpenBSD: input.c,v 1.271 2026/08/31 19:34:09 nicm Exp $ */
 
 /*
  * Copyright (c) 2007 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -145,9 +145,6 @@ struct input_ctx {
 	 */
 	struct evbuffer			*since_ground;
 	struct event			 ground_timer;
-#ifdef ENABLE_IMAGES
-	void				*kitty_state;
-#endif
 };
 
 /* Helper functions. */
@@ -186,9 +183,6 @@ static void	input_enter_osc(struct input_ctx *);
 static void	input_exit_osc(struct input_ctx *);
 static void	input_enter_apc(struct input_ctx *);
 static void	input_exit_apc(struct input_ctx *);
-#ifdef ENABLE_IMAGES
-static int	input_handle_kitty(struct input_ctx *, const u_char *, size_t);
-#endif
 static void	input_enter_rename(struct input_ctx *);
 static void	input_exit_rename(struct input_ctx *);
 
@@ -922,9 +916,6 @@ input_free(struct input_ctx *ictx)
 	event_del(&ictx->request_timer);
 
 	free(ictx->input_buf);
-#ifdef ENABLE_IMAGES
-	kitty_free_state(ictx->kitty_state);
-#endif
 	evbuffer_free(ictx->since_ground);
 	event_del(&ictx->ground_timer);
 
@@ -947,7 +938,6 @@ input_reset(struct input_ctx *ictx, int clear)
 			screen_write_start_pane(sctx, wp, &wp->base);
 		else
 			screen_write_start(sctx, &wp->base);
-		sctx->flags |= SCREEN_WRITE_INPUT;
 		screen_write_reset(sctx);
 		screen_write_stop(sctx);
 	}
@@ -1059,6 +1049,7 @@ input_parse_buffer(struct window_pane *wp, const u_char *buf, size_t len)
 	if (len == 0)
 		return;
 
+	wp->output_generation++;
 	window_update_activity(wp->window);
 	if (~wp->flags & PANE_ACTIVITY) {
 		wp->flags |= PANE_ACTIVITY;
@@ -1075,7 +1066,6 @@ input_parse_buffer(struct window_pane *wp, const u_char *buf, size_t len)
 		screen_write_start_pane(sctx, wp, &wp->base);
 	else
 		screen_write_start(sctx, &wp->base);
-	sctx->flags |= SCREEN_WRITE_INPUT;
 
 	log_debug("%s: %%%u %s, %zu bytes: %.*s", __func__, wp->id,
 	    ictx->state->name, len, (int)len, buf);
@@ -1095,7 +1085,6 @@ input_parse_screen(struct input_ctx *ictx, struct screen *s,
 		return;
 
 	screen_write_start_callback(sctx, s, cb, arg);
-	sctx->flags |= SCREEN_WRITE_INPUT;
 	input_parse(ictx, buf, len);
 	screen_write_stop(sctx);
 }
@@ -1595,7 +1584,7 @@ input_csi_dispatch(struct input_ctx *ictx)
 		case -1:
 			break;
 		case 0:
-#ifdef ENABLE_IMAGES
+#ifdef ENABLE_SIXEL
 			input_reply(ictx, 1, "\033[?1;2;4c");
 #else
 			input_reply(ictx, 1, "\033[?1;2c");
@@ -1990,7 +1979,7 @@ input_csi_dispatch_rm_private(struct input_ctx *ictx)
 			screen_write_mode_clear(sctx, MODE_BRACKETPASTE);
 			break;
 		case 2026:
-			screen_write_stop_sync(ictx->wp);
+			screen_write_end_sync(sctx);
 			break;
 		case 2031:
 			screen_write_mode_clear(sctx, MODE_THEME_UPDATES);
@@ -2113,7 +2102,7 @@ input_csi_dispatch_sm_private(struct input_ctx *ictx)
 static void
 input_csi_dispatch_sm_graphics(__unused struct input_ctx *ictx)
 {
-#ifdef ENABLE_IMAGES
+#ifdef ENABLE_SIXEL
 	int	n, m, o;
 
 	if (ictx->param_list_len > 3)
@@ -2638,10 +2627,10 @@ input_dcs_dispatch(struct input_ctx *ictx)
 	const char		 prefix[] = "tmux;";
 	const u_int		 prefixlen = (sizeof prefix) - 1;
 	long long		 allow_passthrough = 0;
-#ifdef ENABLE_IMAGES
+#ifdef ENABLE_SIXEL
 	struct window		*w;
 	struct sixel_image	*si;
-	int			 p1, p2;
+	int			 p2;
 #endif
 
 	if (wp == NULL)
@@ -2654,18 +2643,15 @@ input_dcs_dispatch(struct input_ctx *ictx)
 		return (0);
 	}
 
-#ifdef ENABLE_IMAGES
+#ifdef ENABLE_SIXEL
 	if (wp != NULL && buf[0] == 'q' && ictx->interm_len == 0) {
 		w = wp->window;
 		if (input_split(ictx) != 0)
 			return (0);
-		p1 = input_get(ictx, 0, 0, 0);
-		if (p1 == -1)
-			p1 = 0;
 		p2 = input_get(ictx, 1, 0, 0);
 		if (p2 == -1)
 			p2 = 0;
-		si = sixel_parse(buf, len, p1, p2, w->xpixel, w->ypixel);
+		si = sixel_parse(buf, len, p2, w->xpixel, w->ypixel);
 		if (si != NULL)
 			screen_write_sixelimage(sctx, si, ictx->cell.cell.bg);
 	}
@@ -2804,57 +2790,6 @@ input_enter_apc(struct input_ctx *ictx)
 }
 
 /* APC terminator (ST) received. */
-#ifdef ENABLE_IMAGES
-static int
-input_handle_kitty(struct input_ctx *ictx, const u_char *buf, size_t len)
-{
-	struct screen_write_ctx	*sctx = &ictx->ctx;
-	struct window_pane	*wp = ictx->wp;
-	struct image		*im;
-	u_int			 image_id = 0, replace_id = 0, quiet = 0;
-	u_int			 placement_id = 0;
-	int32_t			 z = 0;
-	char			 action = '\0', delete = '\0';
-	int			 status;
-
-	if (wp == NULL)
-		return (0);
-	im = kitty_parse_image(&ictx->kitty_state, buf, len,
-		    wp->window->xpixel,
-		    wp->window->ypixel, &image_id, &replace_id, &quiet, &action,
-		    &delete, &placement_id, &z, &status);
-	if (status == KITTY_PARSE_MORE)
-		return (1);
-	if (status != KITTY_PARSE_OK) {
-		if (quiet < 2 && action != '\0') {
-			if (status == KITTY_PARSE_MISSING)
-				input_reply(ictx, 0, "\033_Gi=%u;ENOENT\033\\",
-				    image_id);
-			else
-				input_reply(ictx, 0, "\033_Gi=%u;EINVAL\033\\",
-				    image_id);
-		}
-		return (1);
-	}
-	if (replace_id != 0)
-		image_clear(sctx, replace_id);
-	if (im != NULL) {
-		if (action == 'd')
-			image_clear_kitty(sctx, delete, image_id, placement_id, z);
-		else
-			image_write_kitty(sctx, im, ictx->cell.cell.bg, image_id,
-			    placement_id, z);
-		image_free(image_get_id(im));
-		if (quiet == 0 && image_id != 0)
-			input_reply(ictx, 0, "\033_Gi=%u;OK\033\\", image_id);
-	} else if (action == 'd')
-		image_clear_kitty(sctx, delete, image_id, placement_id, z);
-	else if ((action == 't' || action == 'q' || action == 'u') && quiet == 0)
-		input_reply(ictx, 0, "\033_Gi=%u;OK\033\\", image_id);
-	return (1);
-}
-#endif
-
 static void
 input_exit_apc(struct input_ctx *ictx)
 {
@@ -2865,13 +2800,6 @@ input_exit_apc(struct input_ctx *ictx)
 		return;
 	log_debug("%s: \"%s\"", __func__, ictx->input_buf);
 
-#ifdef ENABLE_IMAGES
-	if (ictx->input_len > 1 && ictx->input_buf[0] == 'G' &&
-	    input_handle_kitty(ictx, ictx->input_buf + 1,
-	    ictx->input_len - 1))
-		return;
-#endif
-
 	if (wp != NULL &&
 	    options_get_number(wp->options, "allow-set-title") &&
 	    screen_set_title(sctx->s, ictx->input_buf, 1)) {
@@ -2932,12 +2860,6 @@ input_top_bit_set(struct input_ctx *ictx)
 {
 	struct screen_write_ctx	*sctx = &ictx->ctx;
 	struct utf8_data	*ud = &ictx->utf8data;
-#ifdef ENABLE_IMAGES
-	struct grid_cell	 gc;
-	struct image		*im;
-	u_int			 x, source_x, source_y, image_id, placement_id;
-	int32_t			 z;
-#endif
 
 	ictx->flags &= ~INPUT_LAST;
 
@@ -2965,20 +2887,6 @@ input_top_bit_set(struct input_ctx *ictx)
 	utf8_copy(&ictx->cell.cell.data, ud);
 	screen_write_collect_add(sctx, &ictx->cell.cell);
 
-#ifdef ENABLE_IMAGES
-	if (sctx->s->cx != 0) {
-		x = sctx->s->cx - 1; /* cx-1 is the cell just written. */
-		grid_view_get_cell(sctx->s->grid, x, sctx->s->cy, &gc);
-		if (kitty_placeholder_to_image(ictx->kitty_state,
-		    sctx->s->grid, &gc, x, sctx->s->cy, &im, &source_x,
-		    &source_y, &image_id, &placement_id, &z)) {
-			grid_view_set_cell(sctx->s->grid, x, sctx->s->cy, &gc);
-			image_place_cell_kitty(sctx, im, x, sctx->s->cy, source_x,
-			    source_y, image_id, placement_id, z);
-		}
-	}
-#endif
-
 	utf8_copy(&ictx->last, &ictx->cell.cell.data);
 	ictx->flags |= INPUT_LAST;
 

key-bindings.c

@@ -53,6 +53,7 @@
 	" '#{?#{m/r:(copy|view)-mode,#{pane_mode}},Go To Bottom,}' '>' {send -X history-bottom}" \
 	" ''" \
 	" '#{?#{==:#{pane_mode},copy-mode},#{?copy_line_numbers,Hide Line Numbers,Show Line Numbers},}' 'L' {send -X line-numbers-toggle}" \
+	" '#{?#{==:#{pane_mode},copy-mode},Edit,}' 'e' {if -F '#{selection_present}' {send -X open-selection} {send -X open-output}}" \
 	" '#{?#{==:#{pane_mode},copy-mode},#{?refresh_active,Refresh Off,Refresh On},}' 'r' {send -X refresh-toggle}" \
 	" ''" \
 	" '#{?#{&&:#{buffer_size},#{!:#{pane_in_mode}}},Paste #[underscore]#{=/9/...:buffer_sample},}' 'p' {paste-buffer}" \
@@ -575,6 +576,7 @@ key_bindings_init(void)
 		"bind -Tcopy-mode C-l { send -X recentre-top-bottom }",
 		"bind -Tcopy-mode M-l { send -X cursor-centre-horizontal }",
 		"bind -Tcopy-mode C-n { send -X cursor-down }",
+		"bind -Tcopy-mode C-o { send -X select-output }",
 		"bind -Tcopy-mode C-p { send -X cursor-up }",
 		"bind -Tcopy-mode C-r { command-prompt -P -T search -ip'(search up)' -I'#{pane_search_string}' { send -X search-backward-incremental -- '%%' } }",
 		"bind -Tcopy-mode C-s { command-prompt -P -T search -ip'(search down)' -I'#{pane_search_string}' { send -X search-forward-incremental -- '%%' } }",
@@ -592,6 +594,7 @@ key_bindings_init(void)
 		"bind -Tcopy-mode R { send -X rectangle-toggle }",
 		"bind -Tcopy-mode T { command-prompt -P -1p'(jump to backward)' { send -X jump-to-backward -- '%%' } }",
 		"bind -Tcopy-mode X { send -X set-mark }",
+		"bind -Tcopy-mode e { if -F '#{selection_present}' { send -X open-selection } { send -X open-output } }",
 		"bind -Tcopy-mode f { command-prompt -P -1p'(jump forward)' { send -X jump-forward -- '%%' } }",
 		"bind -Tcopy-mode g { command-prompt -P -p'(goto line)' { send -X goto-line -- '%%' } }",
 		"bind -Tcopy-mode n { send -X search-again }",
@@ -687,6 +690,8 @@ key_bindings_init(void)
 		"bind -Tcopy-mode-vi K { send -X scroll-up }",
 		"bind -Tcopy-mode-vi L { send -X bottom-line }",
 		"bind -Tcopy-mode-vi M { send -X middle-line }",
+		"bind -Tcopy-mode-vi M-e { if -F '#{selection_present}' { send -X open-selection } { send -X open-output } }",
+		"bind -Tcopy-mode-vi M-o { send -X select-output }",
 		"bind -Tcopy-mode-vi N { send -X search-reverse }",
 		"bind -Tcopy-mode-vi P { send -X toggle-position }",
 		"bind -Tcopy-mode-vi T { command-prompt -P -1p'(jump to backward)' { send -X jump-to-backward -- '%%' } }",

layout.c

@@ -1,4 +1,4 @@
-/* $OpenBSD: layout.c,v 1.96 2026/07/15 13:02:33 nicm Exp $ */
+/* $OpenBSD: layout.c,v 1.100 2026/09/11 08:16:14 nicm Exp $ */
 
 /*
  * Copyright (c) 2009 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -106,7 +106,7 @@ layout_free_cell(struct layout_cell *lc, int only_nodes)
 		}
 		break;
 	case LAYOUT_WINDOWPANE:
-		if (lc->wp != NULL) {
+		if (lc->wp != NULL && lc->wp->layout_cell != NULL) {
 			lc->wp->layout_cell->parent = NULL;
 			lc->wp->layout_cell = NULL;
 		}
@@ -233,29 +233,6 @@ layout_make_node(struct layout_cell *lc, enum layout_type type)
 	lc->wp = NULL;
 }
 
-/* Fix z-indexes. */
-void
-layout_fix_zindexes(struct window *w, struct layout_cell *lc)
-{
-	struct layout_cell	*lcchild;
-
-	if (lc == NULL)
-		return;
-
-	switch (lc->type) {
-	case LAYOUT_WINDOWPANE:
-		TAILQ_INSERT_TAIL(&w->z_index, lc->wp, zentry);
-		break;
-	case LAYOUT_LEFTRIGHT:
-	case LAYOUT_TOPBOTTOM:
-		TAILQ_FOREACH(lcchild, &lc->cells, entry)
-			layout_fix_zindexes(w, lcchild);
-		return;
-	default:
-		fatalx("bad layout type");
-	}
-}
-
 int
 layout_cell_is_tiled(struct layout_cell *lc)
 {
@@ -265,7 +242,7 @@ layout_cell_is_tiled(struct layout_cell *lc)
 	return is_leaf && !is_floating;
 }
 
-static int
+int
 layout_cell_has_tiled_child(struct layout_cell *lc)
 {
 	struct layout_cell      *lcchild;
@@ -509,18 +486,20 @@ layout_fix_panes(struct window *w, struct window_pane *skip)
 
 /* Count the number of available cells in a layout. */
 u_int
-layout_count_cells(struct layout_cell *lc)
+layout_count_cells(struct layout_cell *lc, int with_floating)
 {
 	struct layout_cell	*lcchild;
 	u_int			 count = 0;
 
 	switch (lc->type) {
 	case LAYOUT_WINDOWPANE:
+		if (lc->flags & LAYOUT_CELL_FLOATING && !with_floating)
+			return 0;
 		return (1);
 	case LAYOUT_LEFTRIGHT:
 	case LAYOUT_TOPBOTTOM:
 		TAILQ_FOREACH(lcchild, &lc->cells, entry)
-			count += layout_count_cells(lcchild);
+			count += layout_count_cells(lcchild, with_floating);
 		return (count);
 	default:
 		fatalx("bad layout type");
@@ -539,6 +518,10 @@ layout_resize_check(struct window *w, struct layout_cell *lc,
 
 	status = window_get_pane_status(w);
 
+	/* Floating cells do not take space from the tiled layout. */
+	if (!layout_cell_is_tiled(lc) && !layout_cell_has_tiled_child(lc))
+		return (0);
+
 	if (lc->type == LAYOUT_WINDOWPANE) {
 		/* Space available in this cell only. */
 		if (type == LAYOUT_LEFTRIGHT) {
@@ -568,6 +551,9 @@ layout_resize_check(struct window *w, struct layout_cell *lc,
 		/* Different type: minimum of available space in child cells. */
 		minimum = UINT_MAX;
 		TAILQ_FOREACH(lcchild, &lc->cells, entry) {
+			if (!layout_cell_is_tiled(lcchild) &&
+			    !layout_cell_has_tiled_child(lcchild))
+				continue;
 			available = layout_resize_check(w, lcchild, type);
 			if (available < minimum)
 				minimum = available;
@@ -661,7 +647,7 @@ layout_resize_set_size(struct window *w, struct layout_cell *lc,
 
 /* Find and return the nearest neighbour to a cell in a specific direction. */
 static struct layout_cell *
-layout_cell_get_neighbour_direction(struct layout_cell *lc, int direction)
+layout_cell_get_neighbour_dir(struct layout_cell *lc, int direction)
 {
 	struct layout_cell	*lcn = lc;
 
@@ -695,9 +681,9 @@ layout_cell_get_neighbour(struct layout_cell *lc)
 	if (lc == TAILQ_LAST(&lcparent->cells, layout_cells))
 		direction = !direction;
 
-	lcother = layout_cell_get_neighbour_direction(lc, direction);
+	lcother = layout_cell_get_neighbour_dir(lc, direction);
 	if (lcother == NULL)
-		lcother = layout_cell_get_neighbour_direction(lc, !direction);
+		lcother = layout_cell_get_neighbour_dir(lc, !direction);
 
 	return (lcother);
 }
@@ -714,7 +700,7 @@ layout_destroy_cell(struct window *w, struct layout_cell *lc,
 	/* If no parent, this is the last pane in a window. */
 	lcparent = lc->parent;
 	if (lcparent == NULL) {
-		if (lc->wp != NULL)
+		if (*lcroot == lc)
 			*lcroot = NULL;
 		layout_free_cell(lc, 0);
 		return;
@@ -782,6 +768,49 @@ layout_free(struct window *w, int only_nodes)
 	layout_free_cell(w->layout_root, only_nodes);
 }
 
+/* Move and resize floating panes so they stay inside the window. */
+static void
+layout_clamp_floating_panes(struct window *w, u_int sx, u_int sy)
+{
+	struct window_pane	*wp;
+	struct layout_cell	*lc;
+	u_int			 pad, avail, csx, csy;
+
+	TAILQ_FOREACH(wp, &w->z_index, zentry) {
+		lc = wp->layout_cell;
+		if (lc == NULL || (~lc->flags & LAYOUT_CELL_FLOATING))
+			continue;
+		if (window_pane_get_pane_lines(wp) == PANE_LINES_NONE)
+			pad = 0;
+		else
+			pad = 1;
+
+		csx = lc->g.sx;
+		avail = (sx > 2 * pad) ? sx - 2 * pad : 0;
+		if (csx > avail)
+			csx = (avail > PANE_MINIMUM) ? avail : PANE_MINIMUM;
+		csy = lc->g.sy;
+		avail = (sy > 2 * pad) ? sy - 2 * pad : 0;
+		if (csy > avail)
+			csy = (avail > PANE_MINIMUM) ? avail : PANE_MINIMUM;
+		if (csx != lc->g.sx || csy != lc->g.sy)
+			layout_set_size(lc, csx, csy, lc->g.xoff, lc->g.yoff);
+
+		if (lc->g.xoff + lc->g.sx + pad > sx) {
+			if (lc->g.sx + 2 * pad >= sx)
+				lc->g.xoff = pad;
+			else
+				lc->g.xoff = sx - lc->g.sx - pad;
+		}
+		if (lc->g.yoff + lc->g.sy + pad > sy) {
+			if (lc->g.sy + 2 * pad >= sy)
+				lc->g.yoff = pad;
+			else
+				lc->g.yoff = sy - lc->g.sy - pad;
+		}
+	}
+}
+
 /* Resize the entire layout after window resize. */
 void
 layout_resize(struct window *w, u_int sx, u_int sy)
@@ -802,8 +831,11 @@ layout_resize(struct window *w, u_int sx, u_int sy)
 	 * out proportionately - this should leave the layout fitting the new
 	 * window size.
 	 */
-	if (lc->type == LAYOUT_WINDOWPANE && (lc->flags & LAYOUT_CELL_FLOATING))
+	if (lc->type == LAYOUT_WINDOWPANE && (lc->flags & LAYOUT_CELL_FLOATING)) {
+		layout_clamp_floating_panes(w, sx, sy);
+		layout_fix_panes(w, NULL);
 		return;
+	}
 	xchange = sx - lc->g.sx;
 	xlimit = layout_resize_check(w, lc, LAYOUT_LEFTRIGHT);
 	if (xchange < 0 && xchange < -xlimit)
@@ -833,6 +865,7 @@ layout_resize(struct window *w, u_int sx, u_int sy)
 
 	/* Fix cell offsets. */
 	layout_fix_offsets(w);
+	layout_clamp_floating_panes(w, sx, sy);
 	layout_fix_panes(w, NULL);
 }
 
@@ -860,7 +893,7 @@ layout_resize_pane_to(struct window_pane *wp, enum layout_type type,
 		size = lc->g.sx;
 	else
 		size = lc->g.sy;
-	if (lc == TAILQ_LAST(&lcparent->cells, layout_cells))
+	if (layout_cell_is_last_tiled(lc))
 		change = size - new_size;
 	else
 		change = new_size - size;
@@ -985,11 +1018,11 @@ layout_resize_pane(struct window_pane *wp, enum layout_type type, int change,
 	if (lcparent == NULL)
 		return;
 
-	/* If this is the last cell, move back one. */
-	if (lc == TAILQ_LAST(&lcparent->cells, layout_cells)) {
-		do
-			lc = TAILQ_PREV(lc, layout_cells, entry);
-		while (lc->flags & LAYOUT_CELL_FLOATING);
+	/* If this is the last tiled cell, move back one. */
+	if (layout_cell_is_last_tiled(lc)) {
+		lc = layout_cell_get_neighbour_dir(lc, 0);
+		if (lc == NULL)
+			return;
 	}
 
 	layout_resize_layout(wp->window, lc, type, change, opposite);
@@ -1007,22 +1040,22 @@ layout_resize_pane_grow(struct window *w, struct layout_cell *lc,
 	lcadd = lc;
 
 	/* Look towards the tail for a suitable cell for reduction. */
-	lcremove = TAILQ_NEXT(lc, entry);
+	lcremove = layout_cell_get_neighbour_dir(lc, 1);
 	while (lcremove != NULL) {
 		size = layout_resize_check(w, lcremove, type);
 		if (size > 0)
 			break;
-		lcremove = TAILQ_NEXT(lcremove, entry);
+		lcremove = layout_cell_get_neighbour_dir(lcremove, 1);
 	}
 
 	/* If none found, look towards the head. */
 	if (opposite && lcremove == NULL) {
-		lcremove = TAILQ_PREV(lc, layout_cells, entry);
+		lcremove = layout_cell_get_neighbour_dir(lc, 0);
 		while (lcremove != NULL) {
 			size = layout_resize_check(w, lcremove, type);
 			if (size > 0)
 				break;
-			lcremove = TAILQ_PREV(lcremove, layout_cells, entry);
+			lcremove = layout_cell_get_neighbour_dir(lcremove, 0);
 		}
 	}
 	if (lcremove == NULL)
@@ -1050,13 +1083,13 @@ layout_resize_pane_shrink(struct window *w, struct layout_cell *lc,
 		size = layout_resize_check(w, lcremove, type);
 		if (size != 0)
 			break;
-		lcremove = TAILQ_PREV(lcremove, layout_cells, entry);
+		lcremove = layout_cell_get_neighbour_dir(lcremove, 0);
 	} while (lcremove != NULL);
 	if (lcremove == NULL)
 		return (0);
 
 	/* And add onto the next cell (from the original cell). */
-	lcadd = TAILQ_NEXT(lc, entry);
+	lcadd = layout_cell_get_neighbour_dir(lc, 1);
 	if (lcadd == NULL)
 		return (0);
 
@@ -1650,7 +1683,10 @@ layout_get_tiled_cell(struct cmdq_item *item, struct args *args,
 		return (NULL);
 	}
 
-	window_push_zoom(wp->window, 1, (flags & SPAWN_ZOOM));
+	if (window_active_pane_is_over_zoom(w))
+		window_push_zoom(w, 0, 1);
+	else
+		window_push_zoom(w, 1, (flags & SPAWN_ZOOM));
 	lc = layout_split_pane(wp, type, size, flags);
 	if (lc == NULL)
 		*cause = xstrdup("no space for a new pane");
@@ -1677,8 +1713,10 @@ layout_get_floating_cell(struct cmdq_item *item, struct args *args,
 			return (NULL);
 	}
 
-	if (flags & SPAWN_MODAL)
-		window_push_modal_zoom(w);
+	if (flags & SPAWN_FLOATOVERZOOM)
+		window_push_zoom(wp->window, 0, 1);
+	else if (window_active_pane_is_over_zoom(w))
+		window_push_zoom(wp->window, 0, 1);
 	else
 		window_push_zoom(wp->window, 1, (flags & SPAWN_ZOOM));
 	lcnew = layout_floating_pane(w, wp, &fg);

monitor.c

@@ -1,4 +1,4 @@
-/* $OpenBSD: monitor.c,v 1.7 2026/07/27 19:15:58 nicm Exp $ */
+/* $OpenBSD: monitor.c,v 1.8 2026/09/07 10:15:25 nicm Exp $ */
 
 /*
  * Copyright (c) 2026 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -614,8 +614,10 @@ monitor_parse(const char *value, char **name, enum monitor_type *type, int *id,
 		*type = MONITOR_ALL_WINDOWS;
 	else if (sscanf(what, "@%d", id) == 1 && *id >= 0)
 		*type = MONITOR_WINDOW;
-	else
+	else if (*what == '\0')
 		*type = MONITOR_SESSION;
+	else
+		goto fail;
 	*name = xstrdup(copy);
 	*format = xstrdup(split);
 

options-table.c

@@ -1,4 +1,4 @@
-/* $OpenBSD: options-table.c,v 1.242 2026/07/27 08:03:01 nicm Exp $ */
+/* $OpenBSD: options-table.c,v 1.246 2026/09/11 10:17:16 nicm Exp $ */
 
 /*
  * Copyright (c) 2011 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -76,7 +76,8 @@ static const char *options_table_pane_border_indicators_list[] = {
 	"off", "colour", "arrows", "both", NULL
 };
 static const char *options_table_pane_border_lines_list[] = {
-	"single", "double", "heavy", "simple", "number", "spaces", "none", NULL
+	"single", "double", "heavy", "simple", "number", "spaces", "none",
+	"rounded", NULL
 };
 static const char *options_table_popup_border_lines_list[] = {
 	"single", "double", "heavy", "simple", "rounded", "padded", "none", NULL
@@ -91,7 +92,7 @@ static const char *options_table_window_size_list[] = {
 	"largest", "smallest", "manual", "latest", NULL
 };
 static const char *options_table_remain_on_exit_list[] = {
-	"off", "on", "failed", "key", NULL
+	"off", "on", "failed", "key", "failed-key", NULL
 };
 static const char *options_table_destroy_unattached_list[] = {
 	"off", "on", "keep-last", "keep-group", NULL
@@ -305,6 +306,16 @@ const struct options_table_entry options_table[] = {
 		  "When this is reached, the oldest buffer is deleted."
 	},
 
+	{ .name = "clear-on-attach",
+	  .type = OPTIONS_TABLE_FLAG,
+	  .scope = OPTIONS_TABLE_SERVER,
+	  .default_num = 1,
+	  .text = "Whether to use the alternate screen and clear it when "
+		  "a client is attached. When disabled, tmux does not "
+		  "enter the alternate screen on attach so terminal "
+		  "content before tmux remains in scrollback."
+	},
+
 	{ .name = "command-alias",
 	  .type = OPTIONS_TABLE_STRING,
 	  .scope = OPTIONS_TABLE_SERVER,
@@ -541,7 +552,6 @@ const struct options_table_entry options_table[] = {
 	  .scope = OPTIONS_TABLE_SERVER,
 	  .flags = OPTIONS_TABLE_IS_ARRAY,
 	  .default_str = "xterm*:clipboard:ccolour:cstyle:focus:title,"
-			 "xterm-kitty*:kitty,"
 			 "screen*:title,"
 			 "rxvt*:ignorefkeys",
 	  .separator = ",",
@@ -1241,7 +1251,8 @@ const struct options_table_entry options_table[] = {
 	   * underscore.
 	   */
 	  .default_str = "!\"#$%&'()*+,-./:;<=>?@[\\]^`{|}~",
-	  .text = "Characters considered to separate words."
+	  .text = "Characters considered to separate words; a space matches "
+		  "any character with the Unicode White_Space property."
 	},
 
 	/* Window options. */
@@ -1688,7 +1699,8 @@ const struct options_table_entry options_table[] = {
 	  .choices = options_table_remain_on_exit_list,
 	  .default_num = 0,
 	  .text = "Whether panes should remain ('on'), remain until a key is "
-		  "pressed ('key') or be automatically killed ('off' or "
+		  "pressed after any exit ('key') or after a failure "
+		  "('failed-key'), or be automatically killed ('off' or "
 		  "'failed') when the program inside exits."
 	},
 

popup.c

@@ -1,4 +1,4 @@
-/* $OpenBSD: popup.c,v 1.76 2026/07/14 19:07:03 nicm Exp $ */
+/* $OpenBSD: popup.c,v 1.77 2026/08/28 08:02:16 nicm Exp $ */
 
 /*
  * Copyright (c) 2020 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -79,7 +79,8 @@ popup_free(struct popup_data *pd)
 
 	if (pd->job != NULL)
 		job_free(pd->job);
-	input_free(pd->ictx);
+	if (pd->ictx != NULL)
+		input_free(pd->ictx);
 
 	free(pd->r.ranges);
 	screen_free(&pd->s);

prompt.c

@@ -1,4 +1,4 @@
-/* $OpenBSD: prompt.c,v 1.6 2026/08/17 06:45:16 nicm Exp $ */
+/* $OpenBSD: prompt.c,v 1.7 2026/09/09 07:53:03 nicm Exp $ */
 
 /*
  * Copyright (c) 2026 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -1493,9 +1493,11 @@ append_key:
 		utf8_set(&tmp, key);
 		if (key <= 0x1f || key == 0x7f)
 			tmp.width = 2;
-	} else if (KEYC_IS_UNICODE(key))
+	} else if (KEYC_IS_UNICODE(key)) {
 		utf8_to_data(key, &tmp);
-	else
+		if (tmp.size == 0)
+			return (PROMPT_KEY_HANDLED);
+	} else
 		return (PROMPT_KEY_HANDLED);
 
 	pr->buffer = xreallocarray(pr->buffer, size + 2,

regress/buffers.sh

@@ -28,7 +28,7 @@ $TMUX kill-server 2>/dev/null
 
 TMP=$(mktemp)
 TMP2=$(mktemp)
-trap 'rm -f "$TMP" "$TMP2"; $TMUX kill-server 2>/dev/null' 0 1 15
+trap 'rm -f "$TMP" "$TMP2" "$TMP".*; $TMUX kill-server 2>/dev/null' 0 1 15
 
 # check_ok $cmd...
 #
@@ -270,6 +270,27 @@ if [ $? -eq 0 ]; then
 	exit 1
 fi
 
+# A write error after a successful open must be reported to the server.
+dd if=/dev/zero of="$TMP.big" bs=100000 count=1 2>/dev/null
+check_ok load-buffer -b write-error "$TMP.big"
+mkfifo "$TMP.fifo" || exit 1
+dd if="$TMP.fifo" of="$TMP.got" bs=1 count=8 2>/dev/null &
+reader=$!
+exec 3>"$TMP.fifo"
+out=$($TMUX save-buffer -b write-error "$TMP.fifo" 3>&- 2>&1)
+status=$?
+exec 3>&-
+wait "$reader"
+if [ $status -eq 0 ]; then
+	echo "save-buffer after write error succeeded."
+	exit 1
+fi
+if [ "$(wc -c <"$TMP.got")" -ne 8 ]; then
+	echo "save-buffer write error test wrote wrong amount."
+	exit 1
+fi
+check_ok delete-buffer -b write-error
+
 # save-buffer - writes to stdout and load-buffer - reads from stdin.
 out=$($TMUX save-buffer -b sb -)
 if [ "$out" != "data" ]; then

regress/capture-pane-time.sh

@@ -0,0 +1,38 @@
+#!/bin/sh
+
+# capture-pane -I line timestamps
+
+PATH=/bin:/usr/bin
+TERM=screen
+
+[ -z "$TEST_TMUX" ] && TEST_TMUX=$(readlink -f ../tmux)
+TMUX="$TEST_TMUX -LtestA$$ -f/dev/null"
+TMP=$(mktemp)
+trap '$TMUX kill-server 2>/dev/null; rm -f "$TMP"' 0 1 15
+$TMUX kill-server 2>/dev/null
+
+before=$(date +%s)
+$TMUX new-session -d -x 40 -y 5 'seq 1 12; sleep 10' || exit 1
+sleep 1
+after=$(date +%s)
+
+$TMUX capture-pane -pILF -S - -E - >"$TMP" || exit 1
+awk -v before="$before" -v after="$after" '
+	$1 !~ /^-?[0-9]+$/ || $2 !~ /^[0-9]+$/ { exit 1 }
+	$4 == "1" {
+		if ($2 < before || $2 > after)
+			exit 1
+		history = 1
+	}
+	$4 == "9" {
+		if ($2 != 0)
+			exit 1
+		visible = 1
+	}
+	END { if (!history || !visible) exit 1 }
+' "$TMP" || {
+	cat "$TMP"
+	exit 1
+}
+
+exit 0

regress/choose-tree.sh

@@ -290,4 +290,92 @@ wait_count ': G4' 7
 	fail "window 1 of zzz not killed"
 exit_mode q
 
+# --- help and information preview --------------------------------------------
+# The complete tree help is taller than the 24-line test terminal, where the
+# help renderer deliberately leaves the tree unchanged.
+$TMUX2 resize-window -t out:0 -x 80 -y 50 || exit 1
+i=0
+while [ "$i" -lt 50 ]; do
+	# The inner session has a one-line status, leaving a 49-line window.
+	[ "$($TMUX display-message -p -t aaa:0 '#{window_height}')" -ge 49 ] &&
+		break
+	sleep 0.2
+	i=$((i + 1))
+done
+[ "$i" -lt 50 ] || fail "attached client did not resize for tree help"
+$TMUX choose-tree -t aaa:0 -F 'G5' -O index || exit 1
+wait_count ': G5' 7
+$TMUX2 send-keys -t out:0 F1 || fail "send-keys F1 failed"
+wait_for 'Swap current and previous window'
+# The first key closes help; the second exits the tree.
+$TMUX send-keys -t aaa:0 q q || fail "send-keys help exit failed"
+wait_mode aaa:0 0
+
+$TMUX choose-tree -t aaa:0 -F 'G6' -O index || exit 1
+wait_count ': G6' 7
+$TMUX send-keys -t aaa:0 i || fail "send-keys info failed"
+wait_for 'Session'
+$TMUX send-keys -t aaa:0 i || fail "send-keys preview failed"
+exit_mode q
+
+# --- window swapping and command prompt for current/tagged items -------------
+# Restrict a window-only tree to two disposable windows in aaa. J (the
+# Shift-Down equivalent) swaps their window objects while leaving their indexes
+# in place.
+$TMUX new-window -d -t aaa: -n swap-a 'cat' || exit 1
+$TMUX new-window -d -t aaa: -n swap-b 'cat' || exit 1
+aidx=$($TMUX list-windows -t aaa -F '#{window_index}:#{window_name}' | \
+    awk -F: '$2 == "swap-a" {print $1}')
+bidx=$($TMUX list-windows -t aaa -F '#{window_index}:#{window_name}' | \
+    awk -F: '$2 == "swap-b" {print $1}')
+$TMUX choose-tree -w -t aaa:0 -O index -F 'WT #{window_name}' \
+	-f '#{m:swap-*,#{window_name}}' || exit 1
+wait_count 'WT swap-' 2
+$TMUX send-keys -t aaa:0 g j J || fail "window tree swap failed"
+i=0
+while [ "$i" -lt 50 ]; do
+	aname=$($TMUX display-message -p -t "aaa:$aidx" '#{window_name}')
+	bname=$($TMUX display-message -p -t "aaa:$bidx" '#{window_name}')
+	[ "$aname:$bname" = 'swap-b:swap-a' ] && break
+	sleep 0.2
+	i=$((i + 1))
+done
+[ "$i" -lt 50 ] || fail "window tree did not swap the two windows"
+
+# ':' runs an entered command for the current item and rebuilds the tree when
+# its queued command completes.
+$TMUX set-option -g @tree-command '' || exit 1
+$TMUX send-keys -t aaa:0 : || fail "window tree command prompt failed"
+wait_for '(current)'
+$TMUX send-keys -t aaa:0 -l "set-option -g @tree-command '%%'" || exit 1
+$TMUX send-keys -t aaa:0 Enter || exit 1
+i=0
+while [ "$i" -lt 50 ]; do
+	value=$($TMUX show-option -gqv @tree-command)
+	[ -n "$value" ] && break
+	sleep 0.2
+	i=$((i + 1))
+done
+[ "$i" -lt 50 ] || fail "window tree entered command did not run"
+case "$value" in
+=aaa:*.) ;;
+*) fail "window tree command target was '$value'" ;;
+esac
+
+# Tag both disposable windows and kill them through the tagged confirmation
+# callback. The mode-hosting window is outside the filter and survives.
+$TMUX send-keys -t aaa:0 g j t j t X || fail "tagged kill keys failed"
+wait_for 'Kill 2 tagged?'
+$TMUX send-keys -t aaa:0 y || fail "tagged kill confirmation failed"
+i=0
+while [ "$i" -lt 50 ]; do
+	left=$($TMUX list-windows -t aaa -F '#{window_name}' | \
+	    grep -c '^swap-' || true)
+	[ "$left" -eq 0 ] && break
+	sleep 0.2
+	i=$((i + 1))
+done
+[ "$i" -lt 50 ] || fail "tagged windows were not killed"
+exit_mode q
+
 exit 0

regress/clear-on-attach.sh

@@ -0,0 +1,96 @@
+#!/bin/sh
+
+# With clear-on-attach disabled tmux must preserve the terminal contents by
+# scrolling them away, rather than entering and clearing the alternate screen.
+# Capture the bytes written by a real attached client for both settings.
+
+PATH=/bin:/usr/bin
+TERM=screen
+LC_ALL=C.UTF-8
+export PATH TERM LC_ALL
+
+[ -z "$TEST_TMUX" ] && TEST_TMUX=$(readlink -f ../tmux)
+INNER_ON="$TEST_TMUX -LtestIon$$ -f/dev/null"
+OUTER_ON="$TEST_TMUX -LtestOon$$ -f/dev/null"
+INNER_OFF="$TEST_TMUX -LtestIoff$$ -f/dev/null"
+OUTER_OFF="$TEST_TMUX -LtestOoff$$ -f/dev/null"
+DIR=$(mktemp -d) || exit 1
+
+fail()
+{
+	echo "$*" >&2
+	exit 1
+}
+
+cleanup()
+{
+	$OUTER_ON kill-server 2>/dev/null
+	$INNER_ON kill-server 2>/dev/null
+	$OUTER_OFF kill-server 2>/dev/null
+	$INNER_OFF kill-server 2>/dev/null
+	rm -rf "$DIR"
+}
+trap cleanup 0 1 15
+
+wait_for_client()
+{
+	i=0
+	while [ "$i" -lt 50 ]; do
+		$current_inner list-clients 2>/dev/null | grep -q . && return 0
+		sleep 0.1
+		i=$((i + 1))
+	done
+	fail "inner client did not attach"
+}
+
+capture_attach()
+{
+	setting=$1
+	output=$2
+	go=$DIR/go-$setting
+	if [ "$setting" = on ]; then
+		current_inner=$INNER_ON
+		current_outer=$OUTER_ON
+	else
+		current_inner=$INNER_OFF
+		current_outer=$OUTER_OFF
+	fi
+
+	$current_inner new-session -d -s inner -x40 -y10 \
+	    'exec sleep 100' || exit 1
+	$current_inner set-option -g status off || exit 1
+	$current_inner set-option -g clear-on-attach "$setting" || exit 1
+	$current_outer new-session -d -s outer -x40 -y10 \
+	    "while [ ! -e '$go' ]; do sleep 0.01; done; exec $current_inner attach-session -t inner" || exit 1
+	$current_outer set-option -g status off || exit 1
+	$current_outer pipe-pane -O "cat >'$output'" || exit 1
+	touch "$go"
+	wait_for_client
+	sleep 0.5
+	$current_outer pipe-pane -O || exit 1
+}
+
+on=$DIR/on
+off=$DIR/off
+capture_attach on "$on"
+capture_attach off "$off"
+
+smcup=$(printf '\033[?1049h')
+grep -Fq "$smcup" "$on" || fail "clear-on-attach on did not use smcup"
+if grep -Fq "$smcup" "$off"; then
+	fail "clear-on-attach off used smcup"
+fi
+
+# Some screen terminfo entries have indn (CSI Ps S), while older ones only
+# have ind (newline). The preserving path uses indn once or repeats ind once
+# for every line in the terminal plus one.
+escape=$(printf '\033')
+if ! LC_ALL=C grep -Eq "${escape}\\[[0-9]+S" "$off"; then
+	hex=$(od -An -tx1 -v "$off" | tr -d ' \n')
+	case "$hex" in
+	*0a0a0a0a0a0a0a0a0a0a0a*) ;;
+	*) fail "clear-on-attach off did not scroll the old contents away" ;;
+	esac
+fi
+
+exit 0

regress/client-key-order-focus.sh

@@ -0,0 +1,82 @@
+#!/bin/sh
+
+# send-keys -K injects a key into a client. Commands produced by that key must
+# be inserted immediately after send-keys, before later commands in the same
+# command list. Focus events arriving between a prefix and its following key
+# must be forwarded without cancelling the prefix table.
+
+PATH=/bin:/usr/bin
+TERM=screen
+LC_ALL=C.UTF-8
+export PATH TERM LC_ALL
+
+[ -z "$TEST_TMUX" ] && TEST_TMUX=$(readlink -f ../tmux)
+INNER="$TEST_TMUX -LtestI$$ -f/dev/null"
+OUTER="$TEST_TMUX -LtestO$$ -f/dev/null"
+
+fail()
+{
+	echo "$*" >&2
+	exit 1
+}
+
+cleanup()
+{
+	$OUTER kill-server 2>/dev/null
+	$INNER kill-server 2>/dev/null
+}
+trap cleanup 0 1 15
+
+wait_for_client()
+{
+	i=0
+	while [ "$i" -lt 50 ]; do
+		client=$($INNER list-clients -F '#{client_name}' 2>/dev/null)
+		[ -n "$client" ] && return 0
+		sleep 0.1
+		i=$((i + 1))
+	done
+	fail "inner client did not attach"
+}
+
+wait_for_option()
+{
+	option=$1
+	expected=$2
+	i=0
+	while [ "$i" -lt 50 ]; do
+		actual=$($INNER show-option -gv "$option" 2>/dev/null)
+		[ "$actual" = "$expected" ] && return 0
+		sleep 0.1
+		i=$((i + 1))
+	done
+	fail "$option is '$actual', expected '$expected'"
+}
+
+cleanup
+$INNER new-session -d -s inner -x40 -y10 'exec sleep 100' || exit 1
+$INNER set-option -g status off || exit 1
+$INNER set-option -g focus-events on || exit 1
+$OUTER new-session -d -s outer -x40 -y10 "$INNER attach -t inner" || exit 1
+$OUTER set-option -g status off || exit 1
+wait_for_client
+
+# The binding generated by send-keys -K must run before the command which
+# follows send-keys in this command list. Before the queue-ordering fix this
+# produces AB rather than BA.
+$INNER set-option -g @order '' || exit 1
+$INNER bind-key -n a set-option -gF @order '#{@order}B' || exit 1
+$INNER send-keys -K -c "$client" a \; \
+	set-option -gF @order '#{@order}A' || exit 1
+wait_for_option @order BA
+
+# Put the real attached client in the prefix table, deliver FocusIn, then the
+# bound key. FocusIn is not bindable and must not reset the prefix table.
+$INNER bind-key x set-option -g @focus-prefix yes || exit 1
+$OUTER send-keys C-b || exit 1
+focus_in=$(printf '\033[I')
+$OUTER send-keys -l "$focus_in" || exit 1
+$OUTER send-keys x || exit 1
+wait_for_option @focus-prefix yes
+
+exit 0

regress/clock-mode.sh

@@ -0,0 +1,101 @@
+#!/bin/sh
+
+# Exercise clock-mode initialization, all four styles, its one-second timer,
+# resize into the compact renderer, arbitrary-key exit, and cleanup.
+
+PATH=/bin:/usr/bin
+TERM=screen
+LC_ALL=C.UTF-8
+export PATH TERM LC_ALL
+
+[ -z "$TEST_TMUX" ] && TEST_TMUX=$(readlink -f ../tmux)
+DIR=$(mktemp -d) || exit 1
+TMUX_TMPDIR=$DIR
+export TMUX_TMPDIR
+INNER="$TEST_TMUX -LtestI$$ -f/dev/null"
+OUTER="$TEST_TMUX -LtestO$$ -f/dev/null"
+
+fail()
+{
+	echo "$*" >&2
+	exit 1
+}
+
+cleanup()
+{
+	$OUTER kill-server 2>/dev/null
+	$INNER kill-server 2>/dev/null
+	rm -rf "$DIR"
+}
+trap cleanup 0 1 15
+
+capture()
+{
+	$OUTER capture-pane -p -t outer:0.0 2>/dev/null
+}
+
+wait_mode()
+{
+	want=$1
+	i=0
+	while [ "$i" -lt 50 ]; do
+		got=$($INNER display-message -p -t clock:0 '#{pane_mode}' 2>/dev/null)
+		[ "$got" = "$want" ] && return 0
+		sleep 0.1
+		i=$((i + 1))
+	done
+	fail "pane mode is '$got', expected '$want'"
+}
+
+wait_hashes()
+{
+	i=0
+	while [ "$i" -lt 50 ]; do
+		captured=$(capture)
+		printf '%s\n' "$captured" | grep -q '#' && return 0
+		sleep 0.1
+		i=$((i + 1))
+	done
+	fail "large clock did not render"
+}
+
+$INNER new-session -d -s clock -x80 -y24 'exec sleep 100' || exit 1
+$INNER set-option -g status off || exit 1
+$INNER set-option -g window-size manual || exit 1
+$INNER set-option -w clock-mode-colour red || exit 1
+$OUTER new-session -d -s outer -x80 -y24 "$INNER attach -t clock" || exit 1
+$OUTER set-option -g status off || exit 1
+$OUTER set-option -g window-size manual || exit 1
+sleep 1
+
+for style in 12 24 12-with-seconds 24-with-seconds; do
+	$INNER set-option -w -t clock:0 clock-mode-style "$style" || exit 1
+	$INNER clock-mode -t clock:0 || exit 1
+	wait_mode clock-mode
+	wait_hashes
+	# Let at least one timer callback observe a new second.
+	[ "$style" != 12-with-seconds ] || sleep 1.2
+	$INNER send-keys -t clock:0 x || exit 1
+	wait_mode ''
+done
+
+# Resizing an active mode below the large-glyph threshold selects the compact
+# renderer. A visible time contains a colon and no block-clock hash.
+$INNER clock-mode -t clock:0 || exit 1
+wait_mode clock-mode
+$INNER resize-window -t clock:0 -x20 -y5 || exit 1
+i=0
+while [ "$i" -lt 50 ]; do
+	captured=$(capture)
+	printf '%s\n' "$captured" | grep -Eq '[0-9][0-9]?:[0-9][0-9]' && break
+	sleep 0.1
+	i=$((i + 1))
+done
+[ "$i" -lt 50 ] || fail "compact clock did not render after resize"
+printf '%s\n' "$captured" | grep -q '#' &&
+	fail "compact clock still used large glyphs"
+$INNER send-keys -t clock:0 Enter || exit 1
+wait_mode ''
+
+$INNER has-session -t clock || fail "server died during clock-mode tests"
+exit 0

regress/confirm-before-lock.sh

@@ -0,0 +1,150 @@
+#!/bin/sh
+
+# Exercise confirm-before's waiting and background callbacks, custom keys and
+# prompts, default-yes handling and errors. Also cover all three lock command
+# entry points with a harmless lock-command which leaves a marker.
+
+PATH=/bin:/usr/bin
+TERM=screen
+LC_ALL=C.UTF-8
+export PATH TERM LC_ALL
+
+[ -z "$TEST_TMUX" ] && TEST_TMUX=$(readlink -f ../tmux)
+DIR=$(mktemp -d) || exit 1
+TMUX_TMPDIR=$DIR
+export TMUX_TMPDIR
+INNER="$TEST_TMUX -LtestI$$ -f/dev/null"
+OUTER="$TEST_TMUX -LtestO$$ -f/dev/null"
+
+fail()
+{
+	echo "$*" >&2
+	exit 1
+}
+
+cleanup()
+{
+	$OUTER kill-server 2>/dev/null
+	$INNER kill-server 2>/dev/null
+	rm -rf "$DIR"
+}
+trap cleanup 0 1 15
+
+capture()
+{
+	$OUTER capture-pane -p -t outer:0.0 2>/dev/null
+}
+
+wait_capture()
+{
+	marker=$1
+	i=0
+	while [ "$i" -lt 50 ]; do
+		captured=$(capture)
+		printf '%s\n' "$captured" | grep -Fq "$marker" && return 0
+		sleep 0.1
+		i=$((i + 1))
+	done
+	fail "timed out waiting for '$marker'"
+}
+
+wait_option()
+{
+	want=$1
+	i=0
+	while [ "$i" -lt 50 ]; do
+		got=$($INNER show-option -gqv @confirmed 2>/dev/null)
+		[ "$got" = "$want" ] && return 0
+		sleep 0.1
+		i=$((i + 1))
+	done
+	fail "@confirmed is '$got', expected '$want'"
+}
+
+wait_file()
+{
+	marker=$1
+	i=0
+	while [ "$i" -lt 50 ]; do
+		[ -f "$marker" ] && return 0
+		sleep 0.1
+		i=$((i + 1))
+	done
+	fail "lock command did not create $marker"
+}
+
+$INNER new-session -d -s test -x80 -y24 'exec sleep 100' || exit 1
+$INNER set-option -g status on || exit 1
+$INNER set-option -g status-position bottom || exit 1
+$INNER set-option -g window-size manual || exit 1
+$OUTER new-session -d -s outer -x80 -y24 "$INNER attach -t test" || exit 1
+$OUTER set-option -g status off || exit 1
+$OUTER set-option -g window-size manual || exit 1
+sleep 1
+
+client=$($INNER list-clients -F '#{client_name}')
+[ -n "$client" ] || fail "inner client did not attach"
+
+$INNER bind-key -n M-a confirm-before \
+	'set-option -g @confirmed accepted' || exit 1
+$INNER bind-key -n M-b confirm-before -b -p 'Background?' \
+	'set-option -g @confirmed background' || exit 1
+$INNER bind-key -n M-c confirm-before -c x -p 'Custom?' \
+	'set-option -g @confirmed custom' || exit 1
+$INNER bind-key -n M-y confirm-before -y -p 'Default?' \
+	'set-option -g @confirmed default' || exit 1
+
+# A non-confirming response closes the waiting prompt without running its
+# command; reopening and accepting inserts the command after the waiting item.
+$INNER set-option -g @confirmed sentinel || exit 1
+$OUTER send-keys M-a || exit 1
+wait_capture "Confirm 'set-option'? (y/n)"
+$OUTER send-keys n || exit 1
+sleep 0.2
+wait_option sentinel
+$OUTER send-keys M-a || exit 1
+wait_capture "Confirm 'set-option'? (y/n)"
+$OUTER send-keys y || exit 1
+wait_option accepted
+
+# -b has no waiting queue item and appends its command to the client queue.
+$OUTER send-keys M-b || exit 1
+wait_capture 'Background?'
+$OUTER send-keys y || exit 1
+wait_option background
+
+# A custom printable key is accepted, and -y makes Enter affirmative.
+$OUTER send-keys M-c || exit 1
+wait_capture 'Custom?'
+$OUTER send-keys x || exit 1
+wait_option custom
+$OUTER send-keys M-y || exit 1
+wait_capture 'Default?'
+$OUTER send-keys Enter || exit 1
+wait_option default
+
+# Reject invalid multi-character and control confirmation keys.
+if $INNER confirm-before -b -t "$client" -c xx 'display-message x' \
+    >/dev/null 2>&1; then
+	fail "multi-character confirm key was accepted"
+fi
+if $INNER confirm-before -b -t "$client" -c "$(printf '\001')" \
+    'display-message x' >/dev/null 2>&1; then
+	fail "control confirm key was accepted"
+fi
+
+# lock-client, lock-session and lock-server all send lock-command to the real
+# attached client. The command returns immediately and unlocks the client.
+for kind in client session server; do
+	marker="$DIR/locked-$kind"
+	$INNER set-option -t test lock-command "printf locked >$marker" || exit 1
+	case "$kind" in
+	client) $INNER lock-client -t "$client" || exit 1 ;;
+	session) $INNER lock-session -t test || exit 1 ;;
+	server) $INNER lock-server || exit 1 ;;
+	esac
+	wait_file "$marker"
+done
+
+$INNER has-session -t test || fail "server died during prompt or lock tests"
+exit 0

regress/control-client-new-layouts.sh

@@ -0,0 +1,123 @@
+#!/bin/sh
+
+# Check that control client flags are available in every format expansion path
+# used to produce layouts. The layout strings themselves are tested separately.
+
+PATH=/bin:/usr/bin
+TERM=screen
+LC_ALL=C.UTF-8
+LANG=C.UTF-8
+export PATH TERM LC_ALL LANG
+
+[ -z "$TEST_TMUX" ] && TEST_TMUX=$(readlink -f ../tmux)
+TMUX="$TEST_TMUX -LtestA$$ -f/dev/null"
+
+DIR=$(mktemp -d) || exit 1
+FIFO=$DIR/input
+OUT=$DIR/output
+CFG=$DIR/flags.conf
+PID=
+
+fail()
+{
+	echo "$*" >&2
+	exit 1
+}
+
+cleanup()
+{
+	exec 3>&-
+	[ -n "$PID" ] && kill "$PID" 2>/dev/null
+	$TMUX kill-server 2>/dev/null
+	rm -rf "$DIR"
+}
+trap cleanup EXIT
+
+wait_for()
+{
+	pattern=$1
+	i=0
+
+	while [ "$i" -lt 50 ]; do
+		grep -F -- "$pattern" "$OUT" >/dev/null 2>&1 && return 0
+		if [ -n "$PID" ] && ! kill -0 "$PID" 2>/dev/null; then
+			fail "control client exited waiting for: $pattern"
+		fi
+		sleep 0.1
+		i=$((i + 1))
+	done
+	fail "missing: $pattern"
+}
+
+send()
+{
+	printf '%s\n' "$*" >&3
+}
+
+check_commands()
+{
+	name=$1
+	expected=$2
+	match='#{m:*new-layouts*,#{client_flags}}'
+
+	send "display-message -p 'DISPLAY-$name $match'"
+	wait_for "DISPLAY-$name $expected"
+	send "list-panes -F 'PANES-$name $match'"
+	wait_for "PANES-$name $expected"
+	send "list-windows -F 'WINDOWS-$name $match'"
+	wait_for "WINDOWS-$name $expected"
+	send "list-sessions -F 'SESSIONS-$name $match'"
+	wait_for "SESSIONS-$name $expected"
+	send "list-clients -F 'CLIENTS-$name $match'"
+	wait_for "CLIENTS-$name $expected"
+}
+
+check_config()
+{
+	name=$1
+	expected=$2
+
+	send "source-file '$CFG'"
+	send "display-message -p 'CONFIG-$name #{@config-new-layouts}'"
+	wait_for "CONFIG-$name $expected"
+}
+
+cat >"$CFG" <<'EOF'
+%if #{m:*new-layouts*,#{client_flags}}
+set-option -g @config-new-layouts 1
+%else
+set-option -g @config-new-layouts 0
+%endif
+EOF
+
+$TMUX kill-server 2>/dev/null
+$TMUX new-session -d -s layouts -x 80 -y 24 || exit 1
+$TMUX split-window -h -t layouts: || exit 1
+
+mkfifo "$FIFO" || exit 1
+: >"$OUT"
+$TMUX -C attach-session -t layouts <"$FIFO" >"$OUT" 2>&1 &
+PID=$!
+exec 3>"$FIFO"
+
+send 'display-message -p READY'
+wait_for READY
+
+check_commands OFF 0
+check_config OFF 0
+
+send 'refresh-client -f new-layouts'
+check_commands ON 1
+check_config ON 1
+
+send 'refresh-client -f !new-layouts'
+check_commands OFF-AGAIN 0
+check_config OFF-AGAIN 0
+
+# The list commands also run for unattached command clients. Supplying that
+# client to formats must not make the session loop dereference a NULL session.
+$TMUX list-sessions -F '#{S:all,active}' >/dev/null ||
+	fail "session loop failed for unattached command client"
+$TMUX has-session -t layouts || fail "server exited"
+
+exit 0

regress/control-client-popup.sh

@@ -0,0 +1,63 @@
+#!/bin/sh
+
+# Popups require a tty overlay and cannot be displayed by a control client.
+# A popup command from control mode must be ignored cleanly, leaving the
+# client command queue and server usable.
+
+PATH=/bin:/usr/bin
+TERM=screen
+export PATH TERM
+
+[ -z "$TEST_TMUX" ] && TEST_TMUX=$(readlink -f ../tmux)
+TMUX="$TEST_TMUX -LtestA$$ -f/dev/null"
+DIR=$(mktemp -d) || exit 1
+FIFO=$DIR/input
+OUT=$DIR/output
+RAN=$DIR/popup-ran
+
+fail()
+{
+	echo "$*" >&2
+	exit 1
+}
+
+cleanup()
+{
+	exec 3>&-
+	$TMUX kill-server 2>/dev/null
+	rm -rf "$DIR"
+}
+trap cleanup 0 1 15
+
+mkfifo "$FIFO" || exit 1
+$TMUX new-session -d -s control -x40 -y10 'exec sleep 100' || exit 1
+$TMUX -C attach-session -t control <"$FIFO" >"$OUT" 2>&1 &
+control_pid=$!
+exec 3>"$FIFO"
+
+i=0
+while [ "$i" -lt 50 ]; do
+	$TMUX list-clients -F '#{client_flags}' 2>/dev/null |
+	    grep -q 'control-mode' && break
+	sleep 0.1
+	i=$((i + 1))
+done
+[ "$i" -lt 50 ] || fail "control client did not attach"
+
+printf '%s\n' "display-popup -E 'touch $RAN'" >&3
+printf '%s\n' "display-message -p CONTROL-POPUP-ALIVE" >&3
+
+i=0
+while [ "$i" -lt 50 ]; do
+	grep -q 'CONTROL-POPUP-ALIVE' "$OUT" 2>/dev/null && break
+	if ! kill -0 "$control_pid" 2>/dev/null; then
+		fail "control client exited after display-popup"
+	fi
+	sleep 0.1
+	i=$((i + 1))
+done
+[ "$i" -lt 50 ] || fail "command after control-client popup did not run"
+$TMUX has-session -t control || fail "server exited after control-client popup"
+[ ! -e "$RAN" ] || fail "control client started a popup command"
+
+exit 0

regress/control-client-run-shell-exit.sh

@@ -0,0 +1,38 @@
+#!/bin/sh
+
+# A waited run-shell command can complete after a control client has closed its
+# input and exited. The command queue still references the client until the job
+# callback runs, but control_stop has already destroyed c->control_state. Late
+# command output must be discarded instead of dereferencing the stopped control
+# state and killing the server.
+
+PATH=/bin:/usr/bin
+TERM=screen
+
+[ -z "$TEST_TMUX" ] && TEST_TMUX=$(readlink -f ../tmux)
+TMUX="$TEST_TMUX -Ltest"
+$TMUX kill-server 2>/dev/null
+
+OUT=$(mktemp)
+trap "$TMUX kill-server 2>/dev/null; rm -f $OUT" 0 1 15
+
+$TMUX -f/dev/null new-session -d -s main || exit 1
+
+printf '%s\n' 'run-shell "sleep 0.2; echo TEST"' |
+	$TMUX -f/dev/null -C >"$OUT" 2>&1
+
+sleep 1
+
+$TMUX has-session -t main 2>/dev/null || {
+	echo "server exited after late run-shell output"
+	cat "$OUT"
+	exit 1
+}
+
+grep -q '^%exit' "$OUT" || {
+	echo "control client did not exit"
+	cat "$OUT"
+	exit 1
+}
+
+exit 0

regress/control-client-sanity.sh

@@ -30,8 +30,11 @@ killw
 EOF
 sleep 1
 $TMUX has || exit 1
-$TMUX lsp -aF '#{pane_id} #{window_layout}' >$TMP || exit 1
-cat <<EOF|cmp -s $TMP - || exit 1
+# Use a control client to request legacy layouts, keeping only pane lines
+# from the control protocol output.
+$TMUX -C lsp -aF '#{pane_id} #{window_layout}' |
+	grep '^%[0-9]' >$TMP || exit 1
+cat <<EOF|cmp $TMP - || exit 1
 %0 f5ab,200x200,0,0[200x50,0,0,0,200x149,0,51,3]
 %3 f5ab,200x200,0,0[200x50,0,0,0,200x149,0,51,3]
 %2 dcbd,200x200,0,0[200x100,0,0,2,200x99,0,101,4]

regress/copy-mode-commands.sh

@@ -0,0 +1,253 @@
+#!/bin/sh
+
+# Exercise the broad non-mouse copy-mode command surface: navigation, search,
+# jumps, state toggles, line/end-of-line copies, append, and pipe variants.
+
+PATH=/bin:/usr/bin
+TERM=screen
+LC_ALL=C.UTF-8
+export PATH TERM LC_ALL
+
+[ -z "$TEST_TMUX" ] && TEST_TMUX=$(readlink -f ../tmux)
+DIR=$(mktemp -d) || exit 1
+TMUX_TMPDIR=$DIR
+export TMUX_TMPDIR
+TMUX="$TEST_TMUX -Ltest$$ -f/dev/null"
+
+fail()
+{
+	echo "$*" >&2
+	exit 1
+}
+
+cleanup()
+{
+	$TMUX kill-server 2>/dev/null
+	rm -rf "$DIR"
+}
+trap cleanup 0 1 15
+
+x()
+{
+	$TMUX send-keys -t copy:0 -X "$@" || fail "copy command failed: $*"
+}
+
+wait_mode()
+{
+	want=$1
+	i=0
+	while [ "$i" -lt 50 ]; do
+		got=$($TMUX display-message -p -t copy:0 '#{pane_in_mode}' 2>/dev/null)
+		[ "$got" = "$want" ] && return 0
+		sleep 0.1
+		i=$((i + 1))
+	done
+	fail "pane_in_mode is '$got', expected '$want'"
+}
+
+fresh()
+{
+	$TMUX copy-mode -t copy:0 || exit 1
+	wait_mode 1
+	x history-top
+	x start-of-line
+}
+
+select_text()
+{
+	fresh
+	x begin-selection
+	x cursor-right
+	x cursor-right
+}
+
+$TMUX new-session -d -s copy -x40 -y8 \
+    "sh -c 'i=0; while [ \$i -lt 40 ]; do printf \"  line-%02d needle (a[b]c) end\\n\" \$i; i=\$((i + 1)); done; printf \"\\nparagraph two needle\\n\\nparagraph three\\n\"; printf \"\\033]133;A\\007prompt-one\\n\\033]133;C\\007output-one\\n\\033]133;A\\007prompt-two\\n\\033]133;C\\007output-two\\n\"; exec sleep 100'" ||
+	exit 1
+$TMUX set-option -g status off || exit 1
+$TMUX set-option -g history-limit 200 || exit 1
+
+i=0
+while [ "$i" -lt 50 ]; do
+	history=$($TMUX display-message -p -t copy:0 '#{history_size}')
+	[ "$history" -ge 30 ] && break
+	sleep 0.1
+	i=$((i + 1))
+done
+[ "$i" -lt 50 ] || fail "history did not fill"
+
+fresh
+
+# Copy-mode-specific format callbacks expose the word, line, hyperlink and
+# active search match at the cursor.
+formats=$($TMUX display-message -p -t copy:0 \
+    '#{copy_cursor_word}|#{copy_cursor_line}|#{copy_cursor_hyperlink}|#{search_match}') ||
+	exit 1
+[ -n "$formats" ] || fail "copy-mode cursor formats were empty"
+
+# Cursor, viewport and paragraph commands. Each is asserted by successful
+# dispatch and the final mode-liveness check; detailed word/selection geometry
+# is covered by the existing copy-mode tests.
+for command in back-to-indentation bottom-line top-line middle-line \
+    cursor-centre-vertical cursor-centre-horizontal end-of-line history-bottom \
+    history-top halfpage-down halfpage-up page-down page-up next-paragraph \
+    previous-paragraph next-matching-bracket previous-matching-bracket; do
+	x "$command"
+done
+x goto-line 15
+x set-mark
+x cursor-down
+x jump-to-mark
+
+# OSC 133 prompt and output markers support shell-integration navigation.
+x history-top
+x next-prompt
+case "$($TMUX display-message -p -t copy:0 '#{copy_cursor_line}')" in
+*prompt-one*) ;;
+*) fail "next-prompt did not find prompt-one" ;;
+esac
+x next-prompt
+x previous-prompt
+case "$($TMUX display-message -p -t copy:0 '#{copy_cursor_line}')" in
+*prompt-one*) ;;
+*) fail "previous-prompt did not return to prompt-one" ;;
+esac
+x next-prompt -o
+case "$($TMUX display-message -p -t copy:0 '#{copy_cursor_line}')" in
+*output-one*) ;;
+*) fail "next-prompt -o did not find output-one" ;;
+esac
+
+# Character jumps remember their direction and character for repeat/reverse.
+x jump-forward e
+x jump-again
+x jump-reverse
+x jump-backward e
+x jump-to-forward e
+x jump-to-backward e
+
+# Direct, text and incremental searches cover both directions and the saved
+# search used by again/reverse.
+x search-forward needle
+x search-again
+x search-reverse
+x search-backward needle
+x search-forward-text needle
+x search-backward-text needle
+x search-forward-incremental '=needle'
+x search-forward-incremental '+needle'
+x search-backward-incremental '=needle'
+x search-backward-incremental '-needle'
+
+# Stateful display and behaviour toggles.
+for command in rectangle-on rectangle-off rectangle-toggle \
+    line-numbers-on line-numbers-off line-numbers-toggle \
+    refresh-on refresh-now refresh-off refresh-toggle \
+    scroll-exit-on scroll-exit-off scroll-exit-toggle toggle-position; do
+	x "$command"
+done
+wait_mode 1
+x cancel
+wait_mode 0
+
+# Line and end-of-line copy commands work without an explicit selection.
+fresh
+x select-line
+x copy-selection-and-cancel
+case "$($TMUX show-buffer)" in
+*line-00*) ;;
+*) fail "select-line did not select the current line" ;;
+esac
+
+fresh
+x copy-line
+[ -n "$($TMUX show-buffer)" ] || fail "copy-line produced an empty buffer"
+x cancel
+
+fresh
+x copy-end-of-line
+[ -n "$($TMUX show-buffer)" ] || fail "copy-end-of-line produced an empty buffer"
+x cancel
+
+# Append variants retain or close the mode as advertised.
+$TMUX set-buffer -b append-buffer prefix || exit 1
+select_text
+x append-selection
+appended=$($TMUX show-buffer -b append-buffer)
+case "$appended" in
+prefix*) ;;
+*) fail "append-selection produced '$appended'" ;;
+esac
+x cancel
+
+$TMUX set-buffer -b append-cancel-buffer prefix || exit 1
+select_text
+x append-selection-and-cancel
+wait_mode 0
+appended=$($TMUX show-buffer -b append-cancel-buffer)
+case "$appended" in
+prefix*) ;;
+*) fail "append-selection-and-cancel produced '$appended'" ;;
+esac
+
+# The explicit cancel variants close copy mode.
+fresh
+x copy-line-and-cancel
+wait_mode 0
+fresh
+x copy-end-of-line-and-cancel
+wait_mode 0
+select_text
+x copy-selection-and-cancel
+wait_mode 0
+
+# Pipe wrappers have distinct command handlers. /dev/null keeps the test
+# deterministic while exercising asynchronous pipe job creation and cleanup.
+fresh
+x copy-pipe-line 'cat >/dev/null'
+x cancel
+fresh
+x copy-pipe-line-and-cancel 'cat >/dev/null'
+wait_mode 0
+fresh
+x copy-pipe-end-of-line 'cat >/dev/null'
+x cancel
+fresh
+x copy-pipe-end-of-line-and-cancel 'cat >/dev/null'
+wait_mode 0
+
+select_text
+x copy-pipe-no-clear 'cat >/dev/null'
+x pipe-no-clear 'cat >/dev/null'
+x copy-pipe 'cat >/dev/null'
+x pipe 'cat >/dev/null'
+x cancel
+select_text
+x copy-pipe-and-cancel 'cat >/dev/null'
+wait_mode 0
+select_text
+x pipe-and-cancel 'cat >/dev/null'
+wait_mode 0
+
+# Commands which cancel on downward movement have separate handlers.
+fresh
+x history-bottom
+x bottom-line
+x cursor-down-and-cancel
+wait_mode 0
+fresh
+x history-bottom
+x halfpage-down-and-cancel
+wait_mode 0
+fresh
+x history-bottom
+x page-down-and-cancel
+wait_mode 0
+fresh
+x history-bottom
+x bottom-line
+x scroll-down-and-cancel
+wait_mode 0
+
+$TMUX has-session -t copy || fail "server died during copy-mode commands"
+exit 0

regress/copy-mode-selection-mode.sh

@@ -0,0 +1,81 @@
+#!/bin/sh
+
+# Changing an existing character selection to line mode must reset both ends
+# to complete lines, including when the cursor subsequently crosses the fixed
+# end. An invalid regular-expression search must also discard marks left by a
+# previous successful search.
+
+PATH=/bin:/usr/bin
+TERM=screen
+LC_ALL=C.UTF-8
+export PATH TERM LC_ALL
+
+[ -z "$TEST_TMUX" ] && TEST_TMUX=$(readlink -f ../tmux)
+TMUX="$TEST_TMUX -LtestA$$ -f/dev/null"
+
+fail()
+{
+	echo "$*" >&2
+	exit 1
+}
+
+cleanup()
+{
+	$TMUX kill-server 2>/dev/null
+}
+trap cleanup 0 1 15
+
+$TMUX new-session -d -x30 -y6 \
+	"printf 'alpha\nbeta\ngamma\ndelta\n'; exec sleep 100" || exit 1
+$TMUX set-option -g window-size manual || exit 1
+sleep 1
+
+# A valid regular-expression search creates marks. Replacing it with an
+# invalid expression, growing the mode, and scrolling must not leave an old
+# mark array indexed with the new geometry (the original bug was an ASan heap
+# overflow in this sequence).
+$TMUX copy-mode || exit 1
+$TMUX send-keys -X history-top || exit 1
+$TMUX send-keys -X search-forward beta || exit 1
+[ "$($TMUX display-message -p '#{search_present}')" = 1 ] ||
+	fail "successful search did not create marks"
+$TMUX send-keys -X search-forward '[' || exit 1
+$TMUX resize-window -x40 -y8 || exit 1
+$TMUX send-keys -X scroll-down || exit 1
+[ "$($TMUX display-message -p '#{search_present}')" = 0 ] ||
+	fail "invalid regular expression left stale marks after resize"
+$TMUX send-keys -X cancel || exit 1
+
+# Select part of alpha through part of beta, then change the existing
+# selection to line mode. Both lines, and no partial columns, must be copied.
+$TMUX copy-mode || exit 1
+$TMUX send-keys -X history-top || exit 1
+$TMUX send-keys -N2 -X cursor-right || exit 1
+$TMUX send-keys -X begin-selection || exit 1
+$TMUX send-keys -X cursor-down || exit 1
+$TMUX send-keys -N2 -X cursor-right || exit 1
+$TMUX send-keys -X selection-mode line || exit 1
+[ "$($TMUX display-message -p '#{selection_mode}')" = line ] ||
+	fail "selection did not change to line mode"
+$TMUX send-keys -X copy-selection || exit 1
+expected=$(printf 'alpha\nbeta')
+[ "$($TMUX show-buffer)" = "$expected" ] ||
+	fail "line-mode selection did not expand to complete lines"
+
+# Start with the cursor above the fixed end so selection-mode itself takes the
+# reverse-direction path, then extend it through another line.
+$TMUX copy-mode || exit 1
+$TMUX send-keys -X history-top || exit 1
+$TMUX send-keys -N2 -X cursor-down || exit 1
+$TMUX send-keys -N2 -X cursor-right || exit 1
+$TMUX send-keys -X begin-selection || exit 1
+$TMUX send-keys -X cursor-up || exit 1
+$TMUX send-keys -N2 -X cursor-right || exit 1
+$TMUX send-keys -X selection-mode line || exit 1
+$TMUX send-keys -X cursor-up || exit 1
+$TMUX send-keys -X copy-selection || exit 1
+expected=$(printf 'alpha\nbeta\ngamma')
+[ "$($TMUX show-buffer)" = "$expected" ] ||
+	fail "reversed line-mode selection did not keep complete lines"
+
+exit 0

regress/copy-mode-unicode-whitespace.sh

@@ -0,0 +1,163 @@
+#!/bin/sh
+
+PATH=/bin:/usr/bin
+TERM=screen
+
+[ -z "$TEST_TMUX" ] && TEST_TMUX=$(readlink -f ../tmux)
+
+fail()
+{
+	echo "$1"
+	[ -z "$TMUX" ] || $TMUX kill-server 2>/dev/null
+	exit 1
+}
+
+goto_cell()
+{
+	row=$1
+	column=$2
+
+	$TMUX send-keys -X history-top || fail "$mode: history-top failed"
+	$TMUX send-keys -X start-of-line || fail "$mode: start-of-line failed"
+	[ "$row" -eq 0 ] ||
+	    $TMUX send-keys -X -N "$row" cursor-down ||
+	    fail "$mode: cursor-down failed"
+	[ "$column" -eq 0 ] ||
+	    $TMUX send-keys -X -N "$column" cursor-right ||
+	    fail "$mode: cursor-right failed"
+}
+
+check_cursor()
+{
+	expected=$1
+	actual=$($TMUX display-message -p '#{copy_cursor_x},#{copy_cursor_y}')
+	[ "$actual" = "$expected" ] ||
+	    fail "$mode: expected cursor $expected, got $actual"
+}
+
+check_word()
+{
+	row=$1
+	column=$2
+	expected=$3
+
+	goto_cell "$row" "$column"
+	$TMUX set-buffer sentinel || fail "$mode: set-buffer failed"
+	$TMUX send-keys -X select-word || fail "$mode: select-word failed"
+	$TMUX send-keys -X copy-selection || fail "$mode: copy-selection failed"
+	actual=$($TMUX show-buffer 2>/dev/null)
+	[ "$actual" = "$expected" ] ||
+	    fail "$mode: expected word '$expected', got '$actual'"
+}
+
+check_next_word()
+{
+	row=$1
+	expected=$2
+
+	goto_cell "$row" 0
+	$TMUX send-keys -X next-word || fail "$mode: next-word failed"
+	$TMUX set-buffer sentinel || fail "$mode: set-buffer failed"
+	$TMUX send-keys -X select-word || fail "$mode: select-word failed"
+	$TMUX send-keys -X copy-selection || fail "$mode: copy-selection failed"
+	actual=$($TMUX show-buffer 2>/dev/null)
+	[ "$actual" = "$expected" ] ||
+	    fail "$mode: expected next word '$expected', got '$actual'"
+}
+
+for mode in emacs vi; do
+	TMUX="$TEST_TMUX -Lunicode-whitespace-$mode-$$ -f/dev/null"
+	$TMUX kill-server 2>/dev/null
+	$TMUX new-session -d -x16 -y20 \
+	    "printf 'aa bb\naa\tbb\naa\302\240bb\naa\343\200\200bb\naa:bb\naaaaaaaaaaaaaaa\302\240b\nabcdefghijklmnopq\nhardone\nhardtwo\naa\341\232\200bb\naa\342\200\200bb\naa\342\200\250bb\naa\342\200\251bb\naa\342\200\257bb\naa\342\201\237bb\nxa\302\205b c\n'; exec cat" ||
+	    fail "$mode: new-session failed"
+	$TMUX set-option -g window-size manual || fail "$mode: set size failed"
+	$TMUX set-window-option -g mode-keys "$mode" ||
+	    fail "$mode: set mode-keys failed"
+	$TMUX set-window-option -g word-separators "" ||
+	    fail "$mode: clear word-separators failed"
+	$TMUX copy-mode || fail "$mode: copy-mode failed"
+
+	# ASCII space and TAB retain their existing behaviour.
+	goto_cell 0 0
+	$TMUX send-keys -X next-space || fail "$mode: ASCII next-space failed"
+	check_cursor 3,0
+	goto_cell 1 0
+	$TMUX send-keys -X next-space || fail "$mode: TAB next-space failed"
+	check_cursor 8,1
+	$TMUX send-keys -X previous-space ||
+	    fail "$mode: TAB previous-space failed"
+	check_cursor 0,1
+
+	# NBSP is whitespace for selection and word movement.
+	goto_cell 2 0
+	$TMUX send-keys -X next-word || fail "$mode: NBSP next-word failed"
+	check_cursor 3,2
+	$TMUX send-keys -X previous-word ||
+	    fail "$mode: NBSP previous-word failed"
+	check_cursor 0,2
+	check_word 2 0 aa
+	goto_cell 2 0
+	$TMUX send-keys -X next-word-end ||
+	    fail "$mode: NBSP next-word-end failed"
+	if [ "$mode" = emacs ]; then
+		check_cursor 2,2
+	else
+		check_cursor 1,2
+	fi
+
+	# U+3000 is two columns wide; both its leading and padding cells must be
+	# skipped as one whitespace character in either direction.
+	goto_cell 3 0
+	$TMUX send-keys -X next-word || fail "$mode: U+3000 next-word failed"
+	check_cursor 4,3
+	$TMUX send-keys -X previous-word ||
+	    fail "$mode: U+3000 previous-word failed"
+	check_cursor 0,3
+	goto_cell 3 0
+	$TMUX send-keys -X next-space-end ||
+	    fail "$mode: U+3000 next-space-end failed"
+	if [ "$mode" = emacs ]; then
+		check_cursor 2,3
+	else
+		check_cursor 1,3
+	fi
+
+	# Other characters in word-separators remain literal when space enables
+	# Unicode whitespace matching.
+	$TMUX set-window-option -g word-separators ': ' ||
+	    fail "$mode: set custom word-separators failed"
+	goto_cell 4 0
+	$TMUX send-keys -X next-word || fail "$mode: literal next-word failed"
+	check_cursor 2,4
+	$TMUX set-window-option -g word-separators "" ||
+	    fail "$mode: restore word-separators failed"
+
+	# Whitespace in the last column remains a boundary across a soft wrap.
+	goto_cell 5 0
+	$TMUX send-keys -X next-space ||
+	    fail "$mode: wrapped NBSP next-space failed"
+	check_cursor 0,6
+
+	# A word split only by a soft wrap remains one word, while a hard line
+	# boundary still terminates selection.
+	check_word 7 0 abcdefghijklmnopq
+	check_word 9 0 hardone
+
+	# Check the remaining representative White_Space ranges and U+0085
+	# combined into a cell with another character.
+	check_next_word 11 bb
+	check_next_word 12 bb
+	check_next_word 13 bb
+	check_next_word 14 bb
+	check_next_word 15 bb
+	check_next_word 16 bb
+	goto_cell 17 0
+	$TMUX send-keys -X next-word ||
+	    fail "$mode: combined U+0085 next-word failed"
+	check_cursor 2,17
+
+	$TMUX kill-server 2>/dev/null
+done
+
+exit 0

regress/find-window.sh

@@ -0,0 +1,118 @@
+#!/bin/sh
+
+# Exercise find-window's content, name and title filters in every combination,
+# glob/regex and case-insensitive suffixes, plus zoom restoration.
+
+PATH=/bin:/usr/bin
+TERM=screen
+LC_ALL=C.UTF-8
+export PATH TERM LC_ALL
+
+[ -z "$TEST_TMUX" ] && TEST_TMUX=$(readlink -f ../tmux)
+DIR=$(mktemp -d) || exit 1
+TMUX_TMPDIR=$DIR
+export TMUX_TMPDIR
+INNER="$TEST_TMUX -LtestI$$ -f/dev/null"
+OUTER="$TEST_TMUX -LtestO$$ -f/dev/null"
+
+fail()
+{
+	echo "$*" >&2
+	exit 1
+}
+
+cleanup()
+{
+	$OUTER kill-server 2>/dev/null
+	$INNER kill-server 2>/dev/null
+	rm -rf "$DIR"
+}
+trap cleanup 0 1 15
+
+capture()
+{
+	$OUTER capture-pane -p -t outer:0.0 2>/dev/null
+}
+
+wait_mode()
+{
+	want=$1
+	i=0
+	while [ "$i" -lt 50 ]; do
+		got=$($INNER display-message -p -t find:base.0 '#{pane_mode}' 2>/dev/null)
+		[ "$got" = "$want" ] && return 0
+		sleep 0.1
+		i=$((i + 1))
+	done
+	fail "pane mode is '$got', expected '$want'"
+}
+
+run_find()
+{
+	label=$1
+	expected=$2
+	shift 2
+	$INNER find-window -t find:base.0 "$@" || fail "$label failed"
+	wait_mode tree-mode
+	i=0
+	while [ "$i" -lt 50 ]; do
+		captured=$(capture)
+		printf '%s\n' "$captured" | grep -Fq "$expected" && break
+		sleep 0.1
+		i=$((i + 1))
+	done
+	[ "$i" -lt 50 ] || fail "$label did not show '$expected'"
+	$INNER send-keys -t find:base.0 q || exit 1
+	wait_mode ''
+}
+
+$INNER new-session -d -s find -n base -x80 -y24 \
+	"sh -c 'printf \"BaseBody\\n\"; exec sleep 100'" || exit 1
+$INNER split-window -d -h -t find:base \
+	"sh -c 'printf \"OtherBody\\n\"; exec sleep 100'" || exit 1
+$INNER new-window -d -t find: -n NameNeedle 'exec sleep 100' || exit 1
+$INNER new-window -d -t find: -n body \
+	"sh -c 'printf \"BodyNeedle\\n\"; exec sleep 100'" || exit 1
+$INNER new-window -d -t find: -n titled 'exec sleep 100' || exit 1
+$INNER select-pane -t find:titled.0 -T TitleNeedle || exit 1
+$INNER set-option -g status off || exit 1
+$INNER set-option -g window-size manual || exit 1
+$OUTER new-session -d -s outer -x80 -y24 "$INNER attach -t find:base" || exit 1
+$OUTER set-option -g status off || exit 1
+$OUTER set-option -g window-size manual || exit 1
+sleep 1
+
+# Wait until the body text is in the pane history before searching it.
+i=0
+while [ "$i" -lt 50 ]; do
+	$INNER capture-pane -p -t find:body.0 | grep -Fq BodyNeedle && break
+	sleep 0.1
+	i=$((i + 1))
+done
+[ "$i" -lt 50 ] || fail "pane content was not ready"
+
+# No flags means C+N+T. Then cover all three pairs and all three singletons.
+run_find default NameNeedle NameNeedle
+run_find content-name NameNeedle -C -N NameNeedle
+run_find content-title titled -C -T TitleNeedle
+run_find name-title titled -N -T TitleNeedle
+run_find content-only body -C BodyNeedle
+run_find name-only NameNeedle -N NameNeedle
+run_find title-only titled -T TitleNeedle
+
+# Glob case folding and all regular-expression suffix variants.
+run_find insensitive NameNeedle -N -i nameneedle
+run_find regex NameNeedle -N -r '^NameNeedle$'
+run_find regex-insensitive NameNeedle -N -r -i '^nameneedle$'
+
+# -Z temporarily zooms the target window and restores its prior state on exit.
+$INNER find-window -Z -t find:base.0 -N NameNeedle || exit 1
+wait_mode tree-mode
+[ "$($INNER display-message -p -t find:base '#{window_zoomed_flag}')" = 1 ] ||
+	fail "find-window -Z did not zoom"
+$INNER send-keys -t find:base.0 q || exit 1
+wait_mode ''
+[ "$($INNER display-message -p -t find:base '#{window_zoomed_flag}')" = 0 ] ||
+	fail "find-window -Z did not restore zoom"
+
+exit 0

regress/floating-pane-geometry.sh

@@ -199,5 +199,218 @@ must_fail $TMUX resize-pane -t "$id" -x 0
 must_fail $TMUX resize-pane -t "$id" -y 0
 $TMUX kill-pane -t "$id" || exit 1
 
+# --- Tiled pane resize with floating cells in the layout ---
+
+$TMUX set-option -w -u pane-border-lines || exit 1
+base=$($TMUX display-message -p '#{pane_id}')
+
+# A floating cell after the last tiled cell must not become the recipient of a
+# relative or absolute resize. This is the sequence from GitHub issue 5135.
+floating=$($TMUX new-pane -dPF '#{pane_id}' -t "$base" \
+	-x 50% -y 50% -X 50% -Y 50% 'sleep 100') ||
+	fail "new-pane for tiled resize test failed"
+lower=$($TMUX split-window -dPF '#{pane_id}' -t "$base" 'sleep 100') ||
+	fail "split-window for tiled resize test failed"
+
+$TMUX resize-pane -t "$lower" -U 5 || fail "relative tiled resize failed"
+must_equal "$($TMUX display-message -p -t "$base" '#{pane_height}')" 7
+must_equal "$($TMUX display-message -p -t "$lower" '#{pane_top}')" 8
+must_equal "$($TMUX display-message -p -t "$lower" '#{pane_height}')" 16
+must_equal "$($TMUX display-message -p -t "$floating" '#{pane_top}')" 13
+must_equal "$($TMUX display-message -p -t "$floating" '#{pane_height}')" 10
+
+$TMUX resize-pane -t "$lower" -y 11 || fail "absolute tiled reset failed"
+$TMUX resize-pane -t "$lower" -y 16 || fail "absolute tiled resize failed"
+must_equal "$($TMUX display-message -p -t "$base" '#{pane_height}')" 7
+must_equal "$($TMUX display-message -p -t "$lower" '#{pane_top}')" 8
+must_equal "$($TMUX display-message -p -t "$lower" '#{pane_height}')" 16
+must_equal "$($TMUX display-message -p -t "$floating" '#{pane_height}')" 10
+
+$TMUX kill-pane -t "$floating" || exit 1
+$TMUX kill-pane -t "$lower" || exit 1
+
+# A floating cell between tiled siblings must be skipped when finding the cell
+# which donates space to a resize.
+lower=$($TMUX split-window -dPF '#{pane_id}' -t "$base" 'sleep 100') ||
+	fail "split-window for middle floating cell test failed"
+floating=$($TMUX new-pane -dPF '#{pane_id}' -t "$base" \
+	-x 20 -y 8 -X 30 -Y 8 'sleep 100') ||
+	fail "new-pane for middle floating cell test failed"
+
+$TMUX resize-pane -t "$base" -D 3 || fail "resize past floating cell failed"
+must_equal "$($TMUX display-message -p -t "$base" '#{pane_height}')" 15
+must_equal "$($TMUX display-message -p -t "$lower" '#{pane_top}')" 16
+must_equal "$($TMUX display-message -p -t "$lower" '#{pane_height}')" 8
+must_equal "$($TMUX display-message -p -t "$floating" '#{pane_height}')" 6
+
+$TMUX kill-pane -t "$floating" || exit 1
+$TMUX kill-pane -t "$lower" || exit 1
+
+# A small floating child must not limit the available tiled space in a nested
+# layout with a different split direction.
+lower=$($TMUX split-window -dPF '#{pane_id}' -t "$base" 'sleep 100') ||
+	fail "split-window for nested floating cell test failed"
+right=$($TMUX split-window -dhPF '#{pane_id}' -t "$lower" 'sleep 100') ||
+	fail "horizontal split for nested floating cell test failed"
+floating=$($TMUX new-pane -dPF '#{pane_id}' -t "$lower" \
+	-x 20 -y 3 -X 30 -Y 10 'sleep 100') ||
+	fail "new-pane for nested floating cell test failed"
+
+$TMUX resize-pane -t "$base" -D 3 || fail "nested tiled resize failed"
+must_equal "$($TMUX display-message -p -t "$base" '#{pane_height}')" 15
+must_equal "$($TMUX display-message -p -t "$lower" '#{pane_top}')" 16
+must_equal "$($TMUX display-message -p -t "$lower" '#{pane_height}')" 8
+must_equal "$($TMUX display-message -p -t "$right" '#{pane_top}')" 16
+must_equal "$($TMUX display-message -p -t "$right" '#{pane_height}')" 8
+must_equal "$($TMUX display-message -p -t "$floating" '#{pane_height}')" 1
+
+$TMUX kill-pane -t "$floating" || exit 1
+$TMUX kill-pane -t "$right" || exit 1
+$TMUX kill-pane -t "$lower" || exit 1
+
+# --- Floating panes clamped when the window shrinks (issue #5581, PR #5582) ---
+#
+# layout_resize clamps floating panes back inside the window when it shrinks:
+# move them and, only if they cannot fit, shrink them (never below
+# PANE_MINIMUM). A floating cell is the pane's content, so with the default
+# single-line border the clamp counts 1 cell of border per side, exactly as
+# layout_floating_args_parse does on creation; with no border it counts 0.
+# Each case below gets its own window, since resize-window fixes a window at
+# a manual size for the rest of its life.
+
+# Case 1: a lone floating pane -- break-pane -W on a window's only pane --
+# takes the early-return path in layout_resize, added during PR #5582's
+# review round, since there is no tiled tree to walk.
+win=$($TMUX new-window -dPF '#{window_id}') ||
+	fail "new-window for lone float failed"
+
+# -x 20 -y 6 -> pane 18x4; -X 60 -Y 18 -> pane_left 61, pane_top 19: with the
+# border, the footprint is columns 60-79, rows 18-23, flush with the 80x24
+# window's right and bottom edges, so the float fits before it is shrunk.
+$TMUX break-pane -W -s "$win" -x 20 -y 6 -X 60 -Y 18 ||
+	fail "break-pane -W for lone float failed"
+must_equal "$($TMUX display-message -p -t "$win" '#{pane_width}')"  18
+must_equal "$($TMUX display-message -p -t "$win" '#{pane_height}')" 4
+must_equal "$($TMUX display-message -p -t "$win" '#{pane_left}')"   61
+must_equal "$($TMUX display-message -p -t "$win" '#{pane_top}')"    19
+
+# Shrink to 40x16. The float still fits at its own size (18 <= 40-2, 4 <=
+# 16-2) so only its position moves, flush to the new right/bottom edges:
+# xoff = 40 - 18 - 1 = 21; yoff = 16 - 4 - 1 = 11.
+$TMUX resize-window -t "$win" -x 40 -y 16 ||
+	fail "resize-window (lone float) failed"
+must_equal "$($TMUX display-message -p -t "$win" '#{pane_width}')"  18
+must_equal "$($TMUX display-message -p -t "$win" '#{pane_height}')" 4
+must_equal "$($TMUX display-message -p -t "$win" '#{pane_left}')"   21
+must_equal "$($TMUX display-message -p -t "$win" '#{pane_top}')"    11
+
+# Case 5: grow the window back. The clamp must not chase the window back
+# outward -- it only ever pulls a float in, never restores where it was.
+$TMUX resize-window -t "$win" -x 80 -y 24 ||
+	fail "resize-window grow (lone float) failed"
+must_equal "$($TMUX display-message -p -t "$win" '#{pane_width}')"  18
+must_equal "$($TMUX display-message -p -t "$win" '#{pane_height}')" 4
+must_equal "$($TMUX display-message -p -t "$win" '#{pane_left}')"   21
+must_equal "$($TMUX display-message -p -t "$win" '#{pane_top}')"    11
+$TMUX kill-window -t "$win" || exit 1
+
+# Case 2: the same float, but with a tiled sibling surviving alongside it, so
+# the window's root cell stays tiled and layout_resize takes the normal path
+# (the clamp call after layout_fix_offsets) instead of the early return
+# above. Same geometry as case 1, so the same numbers should come out.
+win=$($TMUX new-window -dPF '#{window_id}') ||
+	fail "new-window for tiled sibling failed"
+$TMUX split-window -t "$win" 'sleep 100' ||
+	fail "split-window for tiled sibling failed"
+$TMUX break-pane -W -s "$win" -x 20 -y 6 -X 60 -Y 18 ||
+	fail "break-pane -W for tiled sibling failed"
+must_equal "$($TMUX display-message -p -t "$win" '#{pane_width}')"  18
+must_equal "$($TMUX display-message -p -t "$win" '#{pane_height}')" 4
+must_equal "$($TMUX display-message -p -t "$win" '#{pane_left}')"   61
+must_equal "$($TMUX display-message -p -t "$win" '#{pane_top}')"    19
+
+$TMUX resize-window -t "$win" -x 40 -y 16 ||
+	fail "resize-window (tiled sibling) failed"
+must_equal "$($TMUX display-message -p -t "$win" '#{pane_width}')"  18
+must_equal "$($TMUX display-message -p -t "$win" '#{pane_height}')" 4
+must_equal "$($TMUX display-message -p -t "$win" '#{pane_left}')"   21
+must_equal "$($TMUX display-message -p -t "$win" '#{pane_top}')"    11
+$TMUX kill-window -t "$win" || exit 1
+
+# Case 3: new-pane float, the original repro from issue #5581 and the PR
+# body -- also the normal path, via the tiled base pane new-window creates.
+win=$($TMUX new-window -dPF '#{window_id}') ||
+	fail "new-window for new-pane repro failed"
+$TMUX resize-window -t "$win" -x 120 -y 40 ||
+	fail "resize-window to 120x40 failed"
+
+# -x 30 -y 10 -> pane 28x8; -X 85 -Y 25 -> pane_left 86, pane_top 26.
+floating=$($TMUX new-pane -t "$win" -dPF '#{pane_id}' \
+	-x 30 -y 10 -X 85 -Y 25 'sleep 100') ||
+	fail "new-pane for new-pane repro failed"
+must_equal "$($TMUX display-message -p -t "$floating" '#{pane_width}')"  28
+must_equal "$($TMUX display-message -p -t "$floating" '#{pane_height}')" 8
+must_equal "$($TMUX display-message -p -t "$floating" '#{pane_left}')"   86
+must_equal "$($TMUX display-message -p -t "$floating" '#{pane_top}')"    26
+
+# Shrink to 60x20: xoff = 60 - 28 - 1 = 31; yoff = 20 - 8 - 1 = 11.
+$TMUX resize-window -t "$win" -x 60 -y 20 ||
+	fail "resize-window (new-pane repro) failed"
+must_equal "$($TMUX display-message -p -t "$floating" '#{pane_width}')"  28
+must_equal "$($TMUX display-message -p -t "$floating" '#{pane_height}')" 8
+must_equal "$($TMUX display-message -p -t "$floating" '#{pane_left}')"   31
+must_equal "$($TMUX display-message -p -t "$floating" '#{pane_top}')"    11
+$TMUX kill-window -t "$win" || exit 1
+
+# Case 4: a float that already fits inside the shrunk window is left alone --
+# assert position and size are both unchanged, not just one of them.
+win=$($TMUX new-window -dPF '#{window_id}') ||
+	fail "new-window for untouched float failed"
+
+# -x 20 -y 6 -> pane 18x4; -X 8 -Y 3 -> pane_left 9, pane_top 4 (as at the top
+# of this file). Footprint columns 8-27, rows 3-8: well inside 60x20 too.
+floating=$($TMUX new-pane -t "$win" -dPF '#{pane_id}' \
+	-x 20 -y 6 -X 8 -Y 3 'sleep 100') ||
+	fail "new-pane for untouched float failed"
+must_equal "$($TMUX display-message -p -t "$floating" '#{pane_width}')"  18
+must_equal "$($TMUX display-message -p -t "$floating" '#{pane_height}')" 4
+must_equal "$($TMUX display-message -p -t "$floating" '#{pane_left}')"   9
+must_equal "$($TMUX display-message -p -t "$floating" '#{pane_top}')"    4
+
+$TMUX resize-window -t "$win" -x 60 -y 20 ||
+	fail "resize-window (untouched float) failed"
+must_equal "$($TMUX display-message -p -t "$floating" '#{pane_width}')"  18
+must_equal "$($TMUX display-message -p -t "$floating" '#{pane_height}')" 4
+must_equal "$($TMUX display-message -p -t "$floating" '#{pane_left}')"   9
+must_equal "$($TMUX display-message -p -t "$floating" '#{pane_top}')"    4
+$TMUX kill-window -t "$win" || exit 1
+
+# Case 6: pad = 0, via the pane-border-lines window option set to none. The
+# border arithmetic differs here (no -2/+1 adjustment either on creation or
+# in the clamp).
+win=$($TMUX new-window -dPF '#{window_id}') ||
+	fail "new-window for pad=0 float failed"
+$TMUX set-option -w -t "$win" pane-border-lines none ||
+	fail "set pane-border-lines none failed"
+
+# No border: -x 20 -y 6 -> pane 20x6 directly; -X 60 -Y 18 -> pane_left 60,
+# pane_top 18 directly. Footprint (== content, no border) is columns 60-79,
+# rows 18-23: flush right/bottom of the 80x24 window, same as case 1.
+$TMUX break-pane -W -s "$win" -x 20 -y 6 -X 60 -Y 18 ||
+	fail "break-pane -W for pad=0 float failed"
+must_equal "$($TMUX display-message -p -t "$win" '#{pane_width}')"  20
+must_equal "$($TMUX display-message -p -t "$win" '#{pane_height}')" 6
+must_equal "$($TMUX display-message -p -t "$win" '#{pane_left}')"   60
+must_equal "$($TMUX display-message -p -t "$win" '#{pane_top}')"    18
+
+# Shrink to 40x16 with pad=0: xoff = 40 - 20 - 0 = 20; yoff = 16 - 6 - 0 = 10.
+$TMUX resize-window -t "$win" -x 40 -y 16 ||
+	fail "resize-window (pad=0 float) failed"
+must_equal "$($TMUX display-message -p -t "$win" '#{pane_width}')"  20
+must_equal "$($TMUX display-message -p -t "$win" '#{pane_height}')" 6
+must_equal "$($TMUX display-message -p -t "$win" '#{pane_left}')"   20
+must_equal "$($TMUX display-message -p -t "$win" '#{pane_top}')"    10
+$TMUX kill-window -t "$win" || exit 1
+
 $TMUX kill-server 2>/dev/null
 exit 0

regress/format-variables.sh

@@ -71,7 +71,10 @@ cursor_very_visible
 cursor_x
 cursor_y
 history_all_bytes
+history_added
 history_bytes
+history_collected
+history_generation
 history_limit
 history_size
 host
@@ -103,6 +106,11 @@ pane_at_right
 pane_at_top
 pane_bg
 pane_bottom
+pane_command_duration
+pane_command_end_time
+pane_command_running
+pane_command_start_time
+pane_command_status
 pane_current_command
 pane_current_path
 pane_dead
@@ -120,16 +128,21 @@ pane_index
 pane_input_off
 pane_key_mode
 pane_last
+pane_last_output_time
+pane_last_prompt_time
 pane_left
 pane_marked
 pane_marked_set
+pane_modal_flag
 pane_mode
+pane_output_generation
 pane_path
 pane_pb_progress
 pane_pb_state
 pane_pid
 pane_pipe
 pane_pipe_pid
+pane_private_modes
 pane_right
 pane_search_string
 pane_start_command
@@ -141,6 +154,8 @@ pane_title
 pane_top
 pane_tty
 pane_unseen_changes
+pane_unzoomed_height
+pane_unzoomed_width
 pane_width
 pane_x
 pane_y
@@ -206,7 +221,10 @@ window_layout
 window_linked
 window_linked_sessions
 window_linked_sessions_list
+window_manual_height
+window_manual_width
 window_marked_flag
+window_modal_pane
 window_name
 window_offset_x
 window_offset_y

regress/hooks-notify.sh

@@ -218,11 +218,13 @@ $TMUX set-hook -gu pane-mode-changed || fail "unset pane-mode-changed failed"
 
 # pane-exited when a pane's command exits with remain-on-exit off.
 $TMUX set -g @x 0 || fail "set @x failed"
-$TMUX set-hook -g pane-exited 'set -gF @x "#{hook}:#{hook_pane}"' ||
+$TMUX set-hook -g pane-exited \
+	'set -gF @x "#{hook}:#{hook_pane}:#{hook_exit_status}:#{hook_exit_success}"' ||
 	fail "set-hook pane-exited failed"
-pane=$($TMUX splitw -d -t main:0 -P -F '#{pane_id}' 'true') ||
-	fail "split-window true failed"
-wait_for @x "pane-exited:$pane"
+pane=$($TMUX splitw -d -t main:0 -P -F '#{pane_id}' \
+	'trap "" HUP; exec </dev/null >/dev/null 2>&1; sleep 1; exit 42') ||
+	fail "split-window exit 42 failed"
+wait_for @x "pane-exited:$pane:42:0"
 $TMUX set-hook -gu pane-exited || fail "unset pane-exited failed"
 
 # pane-died when a pane's command exits with remain-on-exit on.

regress/image-support.sh

@@ -1,437 +0,0 @@
-#!/bin/sh
-
-# Grid-resident image layers: Kitty input, history, copy and overwrite.
-
-PATH=/bin:/usr/bin
-TERM=screen
-
-[ -z "$TEST_TMUX" ] && TEST_TMUX=$(readlink -f ../tmux)
-TMUX="$TEST_TMUX -Limage$$ -f/dev/null"
-TMUX2="$TEST_TMUX -Limage-client$$ -f/dev/null"
-$TMUX kill-server 2>/dev/null
-$TMUX2 kill-server 2>/dev/null
-
-TMP=$(mktemp)
-FIXTURE=$(pwd)/monkey-2.sixel.txt
-trap "$TMUX kill-server 2>/dev/null; $TMUX2 kill-server 2>/dev/null; rm -f $TMP" 0 1 15
-
-$TMUX new-session -d -x 20 -y 8 "
-	printf '\033_Ga=T,q=2,f=32,s=2,v=2,c=2,r=2,m=1;/wAA/wD/\033\\'
-	printf '\033_Gm=0;AP8AAP///////w==\033\\'
-	i=0
-	while [ \$i -lt 10 ]; do printf '\nline-%d' \$i; i=\$((i + 1)); done
-	sleep 10"
-
-sleep 1
-[ "$($TMUX display-message -p '#{image_support}')" = 0 ] && exit 0
-
-# Images scroll as grid cells, while capture output contains ordinary spaces.
-[ "$($TMUX display-message -p '#{history_size}')" -gt 0 ] || exit 1
-$TMUX capture-pane -pS- >$TMP || exit 1
-grep '_G' $TMP >/dev/null && exit 1
-
-# Copy mode duplicates the backing grid, including image layers.
-$TMUX copy-mode || exit 1
-$TMUX send-keys -X history-top || exit 1
-$TMUX capture-pane -p >$TMP || exit 1
-$TMUX send-keys -X cancel || exit 1
-
-# Ordinary text updates the image underlay through the normal grid write path.
-# Deleting the image reveals the newly written text.
-$TMUX new-window -d "
-	printf '\033_Ga=T,q=2,f=32,s=2,v=2,c=2,r=2,i=8;/wAA/wD/AP8AAP///////w==\033\\'
-	printf '\033[HXY'
-	printf '\033_Ga=d,d=i,q=2,i=8\033\\'
-	sleep 10"
-sleep 1
-[ "$($TMUX capture-pane -pt:1 -S0 -E0)" = "XY" ] || exit 1
-
-# The protocol default is transmit-only; a later placement uses the retained
-# immutable image and advances by the same canonical one-cell footprint.
-$TMUX new-window -d "
-	printf '\033_Gq=2,f=32,s=1,v=1,c=1,r=1,i=9;/wAA/w==\033\\'
-	printf '\033_Ga=p,q=2,i=9\033\\'
-	printf '\033_Ga=d,d=I,q=2,i=9\033\\'
-	sleep 10"
-sleep 1
-[ "$($TMUX display-message -pt:2 '#{cursor_y}')" = 1 ] || exit 1
-
-# PNG Kitty input uses the shared image decoder and canonical cell sizing.
-$TMUX new-window -d "
-	printf '\033_Ga=T,q=2,f=100;iVBORw0KGgoAAAANSUhEUgAAAAEAAAABAQMAAAAl21bKAAAAIGNIUk0AAHomAACAhAAA+gAAAIDoAAB1MAAA6mAAADqYAAAXcJy6UTwAAAAGUExURf8AAP///0EdNBEAAAABYktHRAH/Ai3eAAAAB3RJTUUH6ggCDAECH324BwAAAApJREFUCNdjYAAAAAIAAeIhvDMAAAAASUVORK5CYII=\033\\'
-	sleep 10"
-sleep 1
-[ "$($TMUX display-message -pt:3 '#{cursor_y}')" = 1 ] || exit 1
-
-# SIXEL input reaches the same grid layer and copy-mode paths.
-$TMUX new-window -d "cat '$FIXTURE'; sleep 10"
-sleep 1
-[ "$($TMUX display-message -pt:4 '#{cursor_y}')" -gt 0 ] || exit 1
-$TMUX copy-mode -t:4 || exit 1
-$TMUX send-keys -t:4 -X history-top || exit 1
-$TMUX capture-pane -pt:4 >$TMP || exit 1
-
-# A 26-pixel raster occupies two default 16-pixel cells, but the final cell
-# remains only partially filled instead of stretching the raster to 32 pixels.
-# A client without an image feature exposes this in the sampled text backend.
-$TMUX kill-server 2>/dev/null
-$TMUX2 new-session -d -x 10 -y 4 "
-	printf '\033Pq\"1;1;26;26#0;2;100;100;100#0!26~-!26~-!26~-!26~-!26B\033\\'
-	sleep 10" || exit 1
-$TMUX2 set -g status off || exit 1
-$TMUX2 set -as terminal-features ',*:sixel' || exit 1
-$TMUX new-session -d -x 10 -y 4 || exit 1
-$TMUX set -g status off || exit 1
-$TMUX pipe-pane -O "cat >$TMP" || exit 1
-$TMUX send-keys -l "$TMUX2 attach-session" || exit 1
-$TMUX send-keys Enter || exit 1
-sleep 1
-$TMUX capture-pane -pS0 -E0 >$TMP || exit 1
-grep -q '^#=' $TMP || exit 1
-
-# Re-emitting the image preserves the 26-pixel raster rather than expanding
-# it to the two complete 16-pixel grid cells occupied by the image.
-$TMUX pipe-pane || exit 1
-$TMUX pipe-pane -O "cat >$TMP" || exit 1
-$TMUX2 refresh-client -R || exit 1
-sleep 1
-grep -a '"1;1;26;26' $TMP >/dev/null || exit 1
-
-# A selection redraw uses the single-cell path. It must leave ASCII image
-# cells visible (graphical clients skip these cells to avoid erasing pixels).
-$TMUX2 copy-mode || exit 1
-$TMUX2 send-keys -X history-top || exit 1
-$TMUX2 send-keys -X start-of-line || exit 1
-$TMUX2 send-keys -N 4 -X cursor-right || exit 1
-$TMUX2 send-keys -X begin-selection || exit 1
-$TMUX pipe-pane || exit 1
-$TMUX pipe-pane -O "cat >$TMP" || exit 1
-$TMUX2 send-keys -X cursor-right || exit 1
-sleep 1
-$TMUX pipe-pane || exit 1
-grep -a '"1;1;' $TMP >/dev/null && exit 1
-$TMUX capture-pane -pS0 -E0 >$TMP || exit 1
-grep -q '^#=' $TMP || exit 1
-
-# Selection must also leave transparent cells inside the image canvas alone.
-# This 26-pixel canvas paints only its first pixel column, while the text below
-# it keeps the copy-mode cursor movable across both occupied terminal cells.
-$TMUX2 send-keys -X cancel || exit 1
-$TMUX2 new-window -d "
-	printf 'ab\r'
-	printf '\033Pq\"1;1;26;26#0;2;100;100;100#0~-#0~-#0~-#0~-#0B\033\\'
-	sleep 10" || exit 1
-$TMUX2 select-window -t:1 || exit 1
-sleep 1
-$TMUX2 copy-mode || exit 1
-$TMUX2 send-keys -X top-line || exit 1
-$TMUX2 send-keys -X start-of-line || exit 1
-$TMUX2 send-keys -X cursor-right || exit 1
-$TMUX2 send-keys -X begin-selection || exit 1
-$TMUX pipe-pane || exit 1
-$TMUX pipe-pane -O "cat >$TMP" || exit 1
-$TMUX2 send-keys -X cursor-right || exit 1
-sleep 1
-$TMUX pipe-pane || exit 1
-grep -a 'b' $TMP >/dev/null && exit 1
-
-# Scrolling moves the terminal's image rows with its text rows. It must not
-# force tmux to erase and retransmit the complete SIXEL image.
-$TMUX2 send-keys -X cancel || exit 1
-SCROLL_WINDOW=$($TMUX2 new-window -P -F '#{window_id}' \
-    "cat '$FIXTURE'; exec sh") || exit 1
-sleep 1
-$TMUX pipe-pane || exit 1
-$TMUX pipe-pane -O "cat >$TMP" || exit 1
-$TMUX2 send-keys -t"$SCROLL_WINDOW" -l \
-    "i=0; while [ \$i -lt 12 ]; do printf 'scroll-marker-%d\\n' \$i; i=\$((i + 1)); done" || exit 1
-$TMUX2 send-keys -t"$SCROLL_WINDOW" Enter || exit 1
-sleep 1
-grep -a 'scroll-marker-11' $TMP >/dev/null || exit 1
-grep -a '"1;1;' $TMP >/dev/null && exit 1
-
-# A retained Kitty image may be placed repeatedly using source rectangles.
-# Crop the green and white right column from a red/green/blue/white image.
-$TMUX kill-server 2>/dev/null
-$TMUX2 kill-server 2>/dev/null
-$TMUX2 new-session -d -x 10 -y 4 "
-	printf '\033_Ga=t,q=2,f=32,s=2,v=2,i=10;/wAA/wD/AP8AAP///////w==\033\\'
-	printf '\033_Ga=p,q=2,i=10,x=1,y=0,w=1,h=2,c=1,r=2\033\\'
-	sleep 10" || exit 1
-$TMUX2 set -g status off || exit 1
-$TMUX new-session -d -x 10 -y 4 || exit 1
-$TMUX set -g status off || exit 1
-$TMUX send-keys -l "$TMUX2 attach-session" || exit 1
-$TMUX send-keys Enter || exit 1
-sleep 1
-$TMUX capture-pane -pS0 -E1 >$TMP || exit 1
-[ "$(sed -n 1p $TMP)" = "*" ] || exit 1
-[ "$(sed -n 2p $TMP)" = "@" ] || exit 1
-
-# C=1 places the image without moving the cursor or scrolling. The four-row
-# image is clipped at the bottom of this four-row pane, leaving its white last
-# row off screen.
-$TMUX2 new-window -d "
-	printf '\033[2;3H'
-	printf '\033_Ga=T,q=2,C=1,f=32,s=1,v=4,c=1,r=4;AAAA/1VVVf+qqqr//////w==\033\\'
-	sleep 10" || exit 1
-$TMUX2 select-window -t:1 || exit 1
-sleep 1
-[ "$($TMUX2 display-message -p '#{cursor_x},#{cursor_y}')" = "2,1" ] || exit 1
-$TMUX capture-pane -pS0 -E3 >$TMP || exit 1
-[ "$(sed -n 3p $TMP)" = "  -" ] || exit 1
-[ "$(sed -n 4p $TMP)" = "  *" ] || exit 1
-
-# With normal cursor movement, scrolling is calculated from the full image
-# height. Rows which scrolled above the pane are then cropped from the top, so
-# the bottom three source rows remain visible and the cursor is on the last row.
-$TMUX2 new-window -d "
-	printf '\033[3;1H'
-	printf '\033_Ga=T,q=2,f=32,s=1,v=4,c=1,r=4;AAAA/1VVVf+qqqr//////w==\033\\'
-	sleep 10" || exit 1
-$TMUX2 select-window -t:2 || exit 1
-sleep 1
-[ "$($TMUX2 display-message -p '#{cursor_y}')" = 3 ] || exit 1
-$TMUX capture-pane -pS0 -E3 >$TMP || exit 1
-[ "$(sed -n 1p $TMP)" = "-" ] || exit 1
-[ "$(sed -n 2p $TMP)" = "*" ] || exit 1
-[ "$(sed -n 3p $TMP)" = "@" ] || exit 1
-
-# Image rows remain cell-aligned when a narrower terminal causes text
-# reflow. The ten-column rows are clipped to five columns, not split into four
-# wrapped rows.
-$TMUX2 new-window -d "
-	printf '\033_Ga=T,q=2,C=1,f=32,s=1,v=2,c=10,r=2;/wAA//////8=\033\\'
-	sleep 10" || exit 1
-$TMUX2 select-window -t:3 || exit 1
-sleep 1
-$TMUX resize-window -x 5 -y 4 || exit 1
-sleep 1
-[ "$($TMUX2 display-message -p '#{window_width}x#{window_height}')" = "5x4" ] || exit 1
-$TMUX capture-pane -pS0 -E3 >$TMP || exit 1
-[ "$(sed -n 1p $TMP)" = "....." ] || exit 1
-[ "$(sed -n 2p $TMP)" = "@@@@@" ] || exit 1
-[ -z "$(sed -n 3p $TMP)" ] || exit 1
-
-# Kitty virtual placements use U+10EEEE placeholder cells. Keep their rows at
-# fixed coordinates when narrowing the terminal, clipping instead of reflowing
-# the second half onto the following row.
-$TMUX resize-window -x 10 -y 4 || exit 1
-sleep 1
-$TMUX2 new-window -d "
-	printf '\\364\\216\\273\\256\\314\\205\\364\\216\\273\\256\\314\\205\\364\\216\\273\\256\\314\\205\\364\\216\\273\\256\\314\\205\\364\\216\\273\\256\\314\\205'
-	printf '\\364\\216\\273\\256\\314\\205\\364\\216\\273\\256\\314\\205\\364\\216\\273\\256\\314\\205\\364\\216\\273\\256\\314\\205\\364\\216\\273\\256\\314\\205'
-	sleep 10" || exit 1
-$TMUX2 select-window -t:4 || exit 1
-sleep 1
-$TMUX resize-window -x 5 -y 4 || exit 1
-sleep 1
-$TMUX capture-pane -pS0 -E3 >$TMP || exit 1
-[ -n "$(sed -n 1p $TMP)" ] || exit 1
-[ -z "$(sed -n 2p $TMP)" ] || exit 1
-$TMUX resize-window -x 10 -y 4 || exit 1
-sleep 1
-$TMUX capture-pane -pS0 -E3 >$TMP || exit 1
-[ "$(sed -n 1p $TMP | wc -c)" = 61 ] || exit 1
-[ -z "$(sed -n 2p $TMP)" ] || exit 1
-
-# A placement ID supplied with transmit-and-place is reused by a later place.
-# This is the sequence used by chawan: the newline moves the cursor down before
-# the second command, so the folder moves down one row without leaving a copy.
-PLACEMENT_WINDOW=$($TMUX2 new-window -dP -F '#{window_id}' "
-	printf '\033_GC=1,s=26,v=26,p=1,q=2,i=1,a=T,f=100,m=0;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\033\\'
-	printf '\n'
-	sleep 1
-	printf '\033_GC=1,s=26,v=26,p=1,q=2,i=1,a=p;\033\\'
-	printf '\n'
-	sleep 10") || exit 1
-$TMUX2 select-window -t"$PLACEMENT_WINDOW" || exit 1
-sleep 1
-$TMUX capture-pane -pS0 -E3 >$TMP || exit 1
-[ -z "$(sed -n 1p $TMP)" ] || exit 1
-[ -n "$(sed -n 2p $TMP)" ] || exit 1
-
-# A nonzero Kitty placement ID identifies one placement of an image. Reusing
-# the same image and placement IDs moves it rather than leaving the old cells.
-PLACEMENT_WINDOW=$($TMUX2 new-window -dP -F '#{window_id}' "
-	printf '\033_Ga=t,q=2,f=32,s=1,v=1,i=11;/////w==\033\\'
-	printf '\033[2;2H\033_Ga=p,q=2,C=1,i=11,p=7,c=2,r=1\033\\'
-	printf '\033[4;6H\033_Ga=p,q=2,C=1,i=11,p=7,c=2,r=1\033\\'
-	sleep 10") || exit 1
-$TMUX2 select-window -t"$PLACEMENT_WINDOW" || exit 1
-sleep 1
-$TMUX capture-pane -pS0 -E3 >$TMP || exit 1
-[ -z "$(sed -n 2p $TMP)" ] || exit 1
-[ "$(sed -n 4p $TMP)" = "     @@" ] || exit 1
-
-# Deleting one placement ID leaves other placements of the image intact.
-PLACEMENT_WINDOW=$($TMUX2 new-window -dP -F '#{window_id}' "
-	printf '\033_Ga=t,q=2,f=32,s=1,v=1,i=12;/////w==\033\\'
-	printf '\033[2;2H\033_Ga=p,q=2,C=1,i=12,p=7,c=2,r=1\033\\'
-	printf '\033[4;6H\033_Ga=p,q=2,C=1,i=12,p=8,c=2,r=1\033\\'
-	printf '\033_Ga=d,d=i,q=2,i=12,p=7\033\\'
-	sleep 10") || exit 1
-$TMUX2 select-window -t"$PLACEMENT_WINDOW" || exit 1
-sleep 1
-$TMUX capture-pane -pS0 -E3 >$TMP || exit 1
-[ -z "$(sed -n 2p $TMP)" ] || exit 1
-[ "$(sed -n 4p $TMP)" = "     @@" ] || exit 1
-
-# Image layers retain the cells beneath them. Deleting a transparent image
-# must reveal the original text rather than replacing it with spaces.
-PLACEMENT_WINDOW=$($TMUX2 new-window -dP -F '#{window_id}' "
-	printf 'XY'
-	printf '\033[H'
-	printf '\033_Ga=T,q=2,C=1,f=32,s=1,v=1,c=2,r=1,i=13,p=7;////AA==\033\\'
-	printf '\033_Ga=d,d=i,q=2,i=13,p=7\033\\'
-	sleep 10") || exit 1
-$TMUX2 select-window -t"$PLACEMENT_WINDOW" || exit 1
-sleep 1
-[ "$($TMUX2 capture-pane -pS0 -E0)" = "XY" ] || exit 1
-
-# Text written over a Kitty placement updates its underlay without deleting
-# the image. Deleting the placement afterwards reveals the updated text.
-TEXT_WINDOW=$($TMUX2 new-window -dP -F '#{window_id}' "
-	printf 'test\r'
-	printf '\033_Ga=T,q=2,C=1,f=32,s=2,v=2,c=2,r=2,i=14,p=7;/wAA/wD/AP8AAP///////w==\033\\'
-	printf '\r'
-	printf 'test\n'
-	printf 'test\n'
-	$TEST_TMUX wait-for image-text-delete-$$
-	printf '\033_Ga=d,d=i,q=2,i=14,p=7\033\\'
-	sleep 10") || exit 1
-$TMUX2 select-window -t"$TEXT_WINDOW" || exit 1
-sleep 1
-$TMUX capture-pane -pS0 -E1 >$TMP || exit 1
-[ "$(sed -n 1p $TMP)" = ".*st" ] || exit 1
-[ "$(sed -n 2p $TMP)" = " @st" ] || exit 1
-$TMUX2 wait-for -S image-text-delete-$$ || exit 1
-sleep 1
-$TMUX capture-pane -pS0 -E1 >$TMP || exit 1
-[ "$(sed -n 1p $TMP)" = "test" ] || exit 1
-[ "$(sed -n 2p $TMP)" = "test" ] || exit 1
-
-# Kitty z-indexes and SIXEL's temporal plane are properties of the input, not
-# of the outer terminal. Exercise the logical scene through the fallback
-# backend: higher nonnegative z-indexes cover lower ones and text, ordinary
-# negative z-indexes cover backgrounds but not text, and very negative ones
-# remain below the background.
-Z_WINDOW=$($TMUX2 new-window -dP -F '#{window_id}' "
-	printf '\033_Ga=t,q=2,f=32,s=1,v=1,i=21;/wAA/w==\033\\'
-	printf '\033_Ga=t,q=2,f=32,s=1,v=1,i=22;/////w==\033\\'
-	printf 'X\r'
-	printf '\033_Ga=p,q=2,C=1,i=21,p=1,z=2,c=1,r=1\033\\'
-	printf '\033_Ga=p,q=2,C=1,i=22,p=2,z=1,c=1,r=1\033\\'
-	printf '\033[2;1H\033[41m \033[0m\r'
-	printf '\033_Ga=p,q=2,C=1,i=21,p=3,z=-1,c=1,r=1\033\\'
-	printf '\033[3;1HY\r'
-	printf '\033_Ga=p,q=2,C=1,i=21,p=4,z=-1,c=1,r=1\033\\'
-	printf '\033[4;1H\033[41m \033[0m\r'
-	printf '\033_Ga=p,q=2,C=1,i=21,p=5,z=-1073741825,c=1,r=1\033\\'
-	$TEST_TMUX wait-for image-z-top-$$
-	printf '\033_Ga=d,d=z,q=2,z=2\033\\'
-	$TEST_TMUX wait-for image-z-lower-$$
-	printf '\033_Ga=d,d=z,q=2,z=1\033\\'
-	sleep 10") || exit 1
-$TMUX2 select-window -t"$Z_WINDOW" || exit 1
-sleep 1
-$TMUX capture-pane -pS0 -E3 >$TMP || exit 1
-[ "$(sed -n 1p $TMP)" = "." ] || exit 1
-[ "$(sed -n 2p $TMP)" = "." ] || exit 1
-[ "$(sed -n 3p $TMP)" = "Y" ] || exit 1
-[ -z "$(sed -n 4p $TMP)" ] || exit 1
-$TMUX2 wait-for -S image-z-top-$$ || exit 1
-sleep 1
-$TMUX capture-pane -pS0 -E0 >$TMP || exit 1
-[ "$(sed -n 1p $TMP)" = "@" ] || exit 1
-$TMUX2 wait-for -S image-z-lower-$$ || exit 1
-sleep 1
-$TMUX capture-pane -pS0 -E0 >$TMP || exit 1
-[ "$(sed -n 1p $TMP)" = "X" ] || exit 1
-
-# A weighted median at the maximum channel level must still leave colours on
-# both sides of the split. This skewed black, grey and white image used to stop
-# palette generation after one colour instead of producing three.
-$TMUX kill-server 2>/dev/null
-$TMUX2 kill-server 2>/dev/null
-$TMUX2 new-session -d -x 20 -y 4 "
-	printf '\033_Ga=T,q=2,C=1,f=24,s=100,v=1,c=10,r=1;AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICA////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////\033\\'
-	sleep 10" || exit 1
-$TMUX2 set -g status off || exit 1
-$TMUX2 set -as terminal-features ',*:sixel' || exit 1
-$TMUX new-session -d -x 20 -y 4 || exit 1
-$TMUX set -g status off || exit 1
-$TMUX pipe-pane -O "cat >$TMP" || exit 1
-$TMUX send-keys -l "$TMUX2 attach-session" || exit 1
-$TMUX send-keys Enter || exit 1
-sleep 1
-grep -a '#2;2;' $TMP >/dev/null || exit 1
-
-# A pane redraw on a SIXEL terminal must not clear the status line, which is
-# outside the window scene and may not be redrawn after the pane scrolls.
-$TMUX kill-server 2>/dev/null
-$TMUX2 kill-server 2>/dev/null
-$TMUX2 new-session -d -x 20 -y 8 || exit 1
-$TMUX2 set -g 'status-format[0]' 'STATUS' || exit 1
-$TMUX2 set -as terminal-features ',*:sixel' || exit 1
-$TMUX new-session -d -x 20 -y 8 || exit 1
-$TMUX set -g status off || exit 1
-$TMUX send-keys -l "$TMUX2 attach-session" || exit 1
-$TMUX send-keys Enter || exit 1
-sleep 1
-$TMUX2 send-keys -l 'seq 30' || exit 1
-$TMUX2 send-keys Enter || exit 1
-sleep 1
-$TMUX capture-pane -p >$TMP || exit 1
-[ "$(tail -n 1 $TMP)" = "STATUS" ] || exit 1
-
-# A partial redraw of a tiled pane must clear only its visible scene spans.
-# Clearing its entire rectangle would erase a floating pane above it, while
-# the tiled pane redraw correctly skips the obscured area and cannot restore it.
-$TMUX kill-server 2>/dev/null
-$TMUX2 kill-server 2>/dev/null
-$TMUX2 new-session -d -x 40 -y 15 \
-    "printf 'TILED PANE'; sleep 10" || exit 1
-TILED_PANE=$($TMUX2 display-message -p '#{pane_id}') || exit 1
-FLOATING_PANE=$($TMUX2 new-pane -dP -F '#{pane_id}' -x 20 -y 6 -X 10 -Y 4 \
-    "printf 'FLOATING PANE'; sleep 10") || exit 1
-$TMUX2 set -g status off || exit 1
-$TMUX2 set -as terminal-features ',*:sixel' || exit 1
-$TMUX2 select-pane -t"$FLOATING_PANE" || exit 1
-$TMUX new-session -d -x 40 -y 15 || exit 1
-$TMUX set -g status off || exit 1
-$TMUX send-keys -l "$TMUX2 attach-session" || exit 1
-$TMUX send-keys Enter || exit 1
-sleep 1
-$TMUX2 copy-mode -t"$TILED_PANE" || exit 1
-sleep 1
-$TMUX capture-pane -p >$TMP || exit 1
-grep 'TILED PANE' $TMP >/dev/null || exit 1
-grep 'FLOATING PANE' $TMP >/dev/null || exit 1
-
-# An obscured pane is normally redrawn a line at a time when it scrolls, but
-# that path cannot restore graphical image layers. It must defer to the scene
-# redraw so the visible part of the image is emitted around the floating pane.
-IMAGE_PANE=$($TMUX2 new-window -dP -F '#{pane_id}' \
-    "cat '$FIXTURE'; exec sh") || exit 1
-$TMUX2 set -g pane-border-status top || exit 1
-$TMUX2 set -pt"$IMAGE_PANE" pane-border-format 'IMAGE STATUS' || exit 1
-FLOATING_PANE=$($TMUX2 new-pane -dP -F '#{pane_id}' -x 20 -y 6 -X 10 -Y 4 \
-    "printf 'FLOATING PANE'; sleep 10") || exit 1
-$TMUX2 set -pt"$FLOATING_PANE" pane-border-format 'FLOAT STATUS' || exit 1
-$TMUX2 select-pane -t"$FLOATING_PANE" || exit 1
-sleep 1
-$TMUX pipe-pane || exit 1
-$TMUX pipe-pane -O "cat >$TMP" || exit 1
-$TMUX2 send-keys -t"$IMAGE_PANE" -l \
-    "i=0; while [ \$i -lt 5 ]; do printf 'image-scroll-%d\\n' \$i; i=\$((i + 1)); done" || exit 1
-$TMUX2 send-keys -t"$IMAGE_PANE" Enter || exit 1
-sleep 1
-$TMUX pipe-pane || exit 1
-grep -a 'image-scroll-4' $TMP >/dev/null || exit 1
-grep -a '"1;1;' $TMP >/dev/null || exit 1
-$TMUX capture-pane -p >$TMP || exit 1
-grep 'IMAGE STATUS' $TMP >/dev/null || exit 1
-grep 'FLOAT STATUS' $TMP >/dev/null || exit 1
-
-exit 0

regress/json.sh

@@ -0,0 +1,137 @@
+#!/bin/sh
+
+# Test parsing and printing JSON with display-message -j.
+
+PATH=/bin:/usr/bin
+TERM=screen
+
+[ -z "$TEST_TMUX" ] && TEST_TMUX=$(readlink -f ../tmux)
+TMUX="$TEST_TMUX -LtestA$$ -f/dev/null"
+$TMUX kill-server 2>/dev/null
+
+fail()
+{
+	echo "$1"
+	$TMUX kill-server 2>/dev/null
+	exit 1
+}
+
+check()
+{
+	actual=$($TMUX display-message -plj "$1" 2>&1) ||
+	    fail "JSON was rejected: $1: $actual"
+	[ "$actual" = "$2" ] ||
+	    fail "JSON output mismatch: $1: expected $2, got $actual"
+}
+
+check_fail()
+{
+	if $TMUX display-message -plj "$1" >/dev/null 2>&1; then
+		fail "invalid JSON was accepted: $1"
+	fi
+}
+
+$TMUX new-session -d || exit 1
+
+check '{}' '{}'
+check ' { "z":true, "a":-9223372036854775808, "m":[{}, {"x":false}] } ' \
+    '{"a":-9223372036854775808,"m":[{},{"x":false}],"z":true}'
+check '{"max":9223372036854775807,"min":-9223372036854775808}' \
+    '{"max":9223372036854775807,"min":-9223372036854775808}'
+check '{" key":" value","{key":"[value"}' \
+    '{" key":" value","{key":"[value"}'
+check '{"brace":"{value","bracket":"[value","colon":":value",'\
+'"comma":",value","space":" value"}' \
+    '{"brace":"{value","bracket":"[value","colon":":value",'\
+'"comma":",value","space":" value"}'
+check '{"esc":"\"\\\/\b\f\n\r\t\u0041"}' \
+    '{"esc":"\"\\\/\b\f\n\r\t\u0041"}'
+check '{"unicode":"\u0123\uabcd\uABCD"}' \
+    '{"unicode":"\u0123\uabcd\uABCD"}'
+
+actual=$($TMUX display-message -palj '{}' 2>&1) ||
+    fail "display-message -aj rejected JSON: $actual"
+[ "$actual" = '{}' ] ||
+    fail "display-message -aj did not ignore -a: got $actual"
+actual=$($TMUX display-message -pIlj '{}' 2>&1) ||
+    fail "display-message -Ij rejected JSON: $actual"
+[ "$actual" = '{}' ] ||
+    fail "display-message -Ij did not ignore -I: got $actual"
+
+check_fail ''
+check_fail '   '
+check_fail '[]'
+check_fail 'true'
+check_fail '1'
+check_fail '"string"'
+check_fail '{}{}'
+
+check_fail '{'
+check_fail '{x:1}'
+check_fail '{"":1}'
+check_fail '{"x" 1}'
+check_fail '{"x",1}'
+check_fail '{"x":}'
+check_fail '{"x":,}'
+check_fail '{"x":1'
+check_fail '{"x":1 "y":2}'
+check_fail '{"x":1,,"y":2}'
+check_fail '{"x":1,}'
+check_fail '{"x":1,"x":2}'
+check_fail '{"x":{}}{}'
+check_fail '{"x":{}} trailing'
+check_fail '{"x":{'
+check_fail '{"x":{}'
+
+check_fail '{"x":['
+check_fail '{"x":[}'
+check_fail '{"x":[{}'
+check_fail '{"x":[{},}'
+check_fail '{"x":[{},]}'
+check_fail '{"x":[{}{}]}'
+check_fail '{"x":[{},,{}]}'
+check_fail '{"x":[{"y":}]}'
+check_fail '{"x":""}'
+check_fail '{"x":null}'
+check_fail '{"x":[null]}'
+check_fail '{"x":[true]}'
+check_fail '{"x":["string"]}'
+check_fail '{"x":[[]]}'
+check_fail '{"x":1.0}'
+check_fail '{"x":1e2}'
+check_fail '{"x":+1}'
+check_fail '{"x":-}'
+check_fail '{"x":0x10}'
+check_fail '{"x":01}'
+check_fail '{"x":-01}'
+check_fail '{"x":[1]}'
+check_fail '{"x":9223372036854775808}'
+check_fail '{"x":-9223372036854775809}'
+check_fail '{"x":tru}'
+check_fail '{"x":True}'
+check_fail '{"x":falsee}'
+check_fail '{"x":"bad\q"}'
+check_fail '{"x":"bad\x20"}'
+check_fail '{"x":"bad\u123"}'
+check_fail '{"x":"bad\u12x4"}'
+check_fail '{"x":"unterminated}'
+check_fail '{"x":"escaped quote\"}'
+check_fail '{"x":"line
+break"}'
+
+# The maximum object nesting depth is 200.
+json='{}'
+n=1
+while [ "$n" -lt 200 ]; do
+	json='{"x":'"$json"'}'
+	n=$((n + 1))
+done
+check "$json" "$json"
+check_fail '{"x":'"$json"'}'
+
+if $TMUX display-message -pj >/dev/null 2>&1; then
+	fail "display-message -j accepted a missing message"
+fi
+
+$TMUX kill-server 2>/dev/null
+exit 0

regress/layout-custom.sh

@@ -0,0 +1,986 @@
+#!/bin/sh
+
+# Tests of the custom layout dumper and evaluator in layout-custom.c, and of
+# the JSON tokenizer and parser in json.c that the current layout format is
+# built on.
+#
+# layout_dump is reached through the #{window_layout} and
+# #{window_visible_layout} formats and layout_parse through
+# "select-layout <layout>". json.c has no command of its own either:
+# layout_construct sniffs the first non-blank character and hands anything
+# starting with '{' to json_parse, so select-layout is the only way into it
+# from the shell as well.
+#
+# Both layout formats are covered:
+# - the current (v2) JSON format, which is what every client except an old
+#   control client sees;
+# - the legacy (v1) format, which is still produced for a control client that
+#   has not asked for the "new-layouts" flag, and which is still accepted by
+#   the parser (the version is sniffed from the first character).
+#
+# This exercises:
+# - dumping a single pane, a split, the "a" (active) and "l" (last pane) keys
+#   and the "z" key of a floating pane;
+# - #{window_visible_layout} agreeing with #{window_layout};
+# - the JSON syntax itself: insignificant whitespace, backslash escapes inside
+#   strings, the number and boolean forms, and one failure for each way json.c
+#   can reject an input that a layout string can carry;
+# - a dump being parsed back to exactly the same layout (round trip), after
+#   another layout has been applied in between, and the same for a layout with
+#   two floating panes in it;
+# - parsing a hand-written v2 layout;
+# - "i" deciding which pane goes in which cell, checked with a layout whose
+#   cells are written in a different order from their indexes;
+# - the same layouts with their fields in reversed and scrambled orders,
+#   including "c" before "t" and "V" after "L", neither of which changes the
+#   order the fields are read in;
+# - a layout with more cells than the window has panes having the bottom right
+#   cells dropped, in both formats;
+# - a layout naming no active or last pane leaving the active pane where it was
+#   and emptying the last pane stack, whether it leaves "a" out or gives it as
+#   false;
+# - parsing a v1 layout and dumping it back as v1 through a control client,
+#   with the checksum computed here independently of layout_checksum(), and a
+#   v1 layout leaving the active pane and last pane stack untouched;
+# - the legacy format meeting the floating panes it cannot represent: a v1 dump
+#   dropping the floating cells, both where that leaves the node they were in
+#   with one child so that it collapses, where it does not, and where adjacent
+#   nested floating-only subtrees are dropped, and a v1 layout being applied to
+#   a window that has floating panes without disturbing them, whether the tiled
+#   layout it names is a single cell or a split;
+# - a window whose only tiled pane has been killed, which leaves it with a
+#   floating cell as its layout root or with a root node holding nothing but
+#   floating cells, producing no v1 dump at all, and being parsed as v1;
+# - the %layout-change notification, in both formats at once: two control
+#   clients watching one layout change, only one of which has asked for new
+#   layouts, and the number of notifications a change produces in each format;
+# - failures: a bad v1 header, checksum or body, a wrong version, a missing or
+#   duplicated root cell, missing sizes, sizes out of range, bad cell types, a
+#   pane cell missing "i", leaf cells with children and node cells with fewer
+#   than two, more than one active pane, too few cells for the panes and
+#   inconsistent sizes.
+
+PATH=/bin:/usr/bin
+TERM=screen
+LANG=C.UTF-8
+LC_ALL=C.UTF-8
+export TERM LANG LC_ALL
+
+[ -z "$TEST_TMUX" ] && TEST_TMUX=$(readlink -f ../tmux)
+TMUX="$TEST_TMUX -LtestA$$ -f/dev/null"
+$TMUX kill-server 2>/dev/null
+
+fail()
+{
+	echo "$*" >&2
+	$TMUX kill-server 2>/dev/null
+	exit 1
+}
+
+# must_equal $what $got $expected
+must_equal()
+{
+	if [ "$2" != "$3" ]; then
+		echo "$1 wrong." >&2
+		echo "Expected: '$3'" >&2
+		echo "But got:  '$2'" >&2
+		$TMUX kill-server 2>/dev/null
+		exit 1
+	fi
+}
+
+# must_differ $what $got $unwanted
+must_differ()
+{
+	[ "$2" != "$3" ] || fail "$1 unchanged: '$2'"
+}
+
+# must_contain $what $got $wanted
+must_contain()
+{
+	case "$2" in
+	*"$3"*) ;;
+	*) fail "$1: '$2' does not contain '$3'";;
+	esac
+}
+
+# check_ok $cmd...
+#
+# Run a command and require that it succeeds.
+check_ok()
+{
+	out=$($TMUX "$@" 2>&1) || fail "Command failed (expected success): $* ($out)"
+}
+
+# check_fail $cmd...
+#
+# Run a command and require that it fails. The error text itself is never
+# checked anywhere in this test: the wording of a message is not part of what
+# the layout formats promise, so matching on it only makes the test fail when a
+# message is reworded.
+check_fail()
+{
+	$TMUX "$@" >/dev/null 2>&1 &&
+		fail "Command succeeded (expected failure): $*"
+}
+
+# layout $target
+#
+# The layout of a window with pane ids replaced by %N, so that the expected
+# strings do not depend on which ids the server handed out.
+layout()
+{
+	$TMUX display-message -p -t "$1" '#{window_layout}' |
+		sed 's/%[0-9][0-9]*/%N/g'
+}
+
+# visible_layout $target
+#
+# As layout(), but the visible (zoomed) layout.
+visible_layout()
+{
+	$TMUX display-message -p -t "$1" '#{window_visible_layout}' |
+		sed 's/%[0-9][0-9]*/%N/g'
+}
+
+# raw_layout $target
+#
+# The layout of a window with the real pane ids left in place.
+raw_layout()
+{
+	$TMUX display-message -p -t "$1" '#{window_layout}'
+}
+
+# v1_layout $target
+#
+# The legacy (v1) dump of a window, which is what a control client that has not
+# asked for the "new-layouts" flag is sent. A control client wraps its output in
+# %begin/%end guard lines, which are dropped here.
+v1_layout()
+{
+	$TMUX -C display-message -p -t "$1" '#{window_layout}' | grep -v '^%'
+}
+
+# v1 $body
+#
+# Prefix a legacy (v1) layout body with its checksum. This is a separate
+# implementation of layout_checksum(): a 16 bit rotate right then add, so a
+# mistake in either one shows up as a mismatch.
+v1()
+{
+	awk -v s="$1" 'BEGIN {
+		for (i = 32; i < 127; i++)
+			ord[sprintf("%c", i)] = i
+		csum = 0
+		for (i = 1; i <= length(s); i++) {
+			csum = int(csum / 2) + (csum % 2) * 32768
+			csum = (csum + ord[substr(s, i, 1)]) % 65536
+		}
+		printf "%04x,%s\n", csum, s
+	}'
+}
+
+# A pane cell is dumped as its geometry, then "a" if it is the active pane or
+# "l" with its position on the last pane stack if it is on it, then "i" with
+# its pane index, then "z" if it is floating, then "I" with its pane id.
+ONE='{"V":2,"L":{"t":"p","w":80,"h":24,"x":0,"y":0,"a":true,"i":0,"I":"%N"}}'
+
+check_ok new-session -d -s L -x 80 -y 24 -n one
+
+p0=$($TMUX display-message -p -t L:one.0 '#{pane_id}')
+
+# A single leaf cell filling the window. A pane cell must carry "i", its pane
+# index; "I", its pane id, is written by the dumper and is here so that the cell
+# is the same shape as a dumped one. The JSON checks below care about the syntax
+# around the cell rather than the cell itself.
+LEAF='{"t":"p","w":80,"h":24,"x":0,"y":0,"i":0,"I":"'"$p0"'"}'
+
+# ---------------------------------------------------------------------------
+# Dumping a single pane.
+
+# The root cell of a new window is the pane itself, and it is the active pane
+# so it has "a" rather than "l".
+must_equal 'Single pane layout' "$(layout L:one)" "$ONE"
+
+# Nothing is zoomed, so the visible layout is the same.
+must_equal 'Single pane visible layout' "$(visible_layout L:one)" "$ONE"
+
+# ---------------------------------------------------------------------------
+# More cells than panes.
+
+# The bottom right cells are closed until as many are left as there are panes,
+# so a two cell layout applied to a one pane window collapses back to the
+# single pane filling the window: the cell that is left takes the space of the
+# one that was closed. The window has one pane to name, so the cell that is
+# closed carries an id belonging to no pane of it.
+check_ok select-layout -t L:one \
+	'{"V":2,"L":{"t":"v","w":80,"h":24,"x":0,"y":0,"c":[{"t":"p","w":80,"h":11,"x":0,"y":0,"i":0,"I":"'"$p0"'"},{"t":"p","w":80,"h":12,"x":0,"y":12,"i":1,"I":"%999"}]}}'
+must_equal 'Trimmed layout' "$(layout L:one)" "$ONE"
+
+# ---------------------------------------------------------------------------
+# The JSON syntax.
+#
+# These run on the one pane window and are written so that what they prove
+# depends on json.c rather than on the layout evaluation in layout-custom.c:
+# an accepted layout is only required to leave the window as its single pane,
+# and values that are not part of the layout format are carried on keys
+# layout-custom.c never looks at ("n", "b" and so on), which it skips, so
+# numbers, booleans and escapes can be exercised on their own.
+#
+# Objects nested in an array nested in an object are not checked here: every
+# split layout below is one.
+#
+# Two of json.c's rejections cannot be reached from the shell and so are not
+# covered: json_parse_tokens() refusing a top level that is not an object,
+# because layout_construct() only calls json_parse() once the string already
+# starts with '{'; and the maximum object depth, which needs a layout built by a
+# program rather than one written out here.
+
+# check_json_ok $what $layout
+#
+# select-layout must parse $layout and leave the window as its single pane.
+check_json_ok()
+{
+	check_ok select-layout -t L:one "$2"
+	must_equal "Layout after '$1'" "$(layout L:one)" "$ONE"
+}
+
+# check_json_fail $what $layout
+#
+# select-layout must reject $layout.
+check_json_fail()
+{
+	$TMUX select-layout -t L:one "$2" >/dev/null 2>&1 &&
+		fail "$1: select-layout succeeded (expected failure)"
+}
+
+# Whitespace between tokens is skipped. A number is scanned up to the ',', ']',
+# '}' or whitespace that ends it, so a space after a number is fine but one
+# inside it is not.
+check_json_ok 'Spaces between tokens' \
+	'{ "V" : 2 , "L" : { "t" : "p" , "w" : 80 , "h" : 24 , "x" : 0 , "y" : 0 , "i" : 0 , "I" : "'"$p0"'" } }'
+
+check_json_ok 'Newlines and tabs between tokens' "$(printf '{
+\t"V": 2,
+\t"L": {
+\t\t"t": "p",
+\t\t"w": 80,
+\t\t"h": 24,
+\t\t"x": 0,
+\t\t"y": 0,
+\t\t"i": 0,
+\t\t"I": "%s"
+\t}
+}' "$p0")"
+
+check_json_ok 'Carriage returns between tokens' \
+	"$(printf '{\r"V":2,\r"L":%s\r}' "$LEAF")"
+
+# A backslash makes the tokenizer consume the next character whatever it is, so
+# an escaped quote does not end the string. The key is not one that
+# layout-custom.c looks at, so all that is being checked is that the string
+# ended in the right place and the object still parsed.
+check_json_ok 'Escaped quote in a string' \
+	'{"V":2,"a\"b":0,"L":'"$LEAF"'}'
+
+# An escaped backslash immediately before the closing quote: the escape has to
+# be cleared again so that the quote after it does end the string.
+check_json_ok 'Escaped backslash before the closing quote' \
+	'{"V":2,"a\\":0,"L":'"$LEAF"'}'
+
+# Numbers and booleans, again on keys layout-custom.c ignores, so only json.c
+# decides whether they are accepted.
+check_json_ok 'Zero' '{"V":2,"n":0,"L":'"$LEAF"'}'
+check_json_ok 'Several digits' '{"V":2,"n":1234567,"L":'"$LEAF"'}'
+check_json_ok 'Negative number' '{"V":2,"n":-42,"L":'"$LEAF"'}'
+check_json_ok 'Booleans' '{"V":2,"b":true,"d":false,"L":'"$LEAF"'}'
+
+# Tokenizer failures. A value that runs to the end of the input has no
+# terminator, so it is the tokenizer rather than the parser that gives up. Both
+# the number scan and the string scan have to notice this, and with the closing
+# quote escaped there is no terminator left either.
+check_json_fail 'Unterminated number' '{"V":2'
+check_json_fail 'Unterminated string' '{"V":"x'
+check_json_fail 'Escaped closing quote' '{"V":2,"L":{"t":"p\"}}'
+
+# Something that is not a quoted string where a key belongs.
+check_json_fail 'Missing key' '{"V":2,,"L":'"$LEAF"'}'
+
+# A key not followed by ':'.
+check_json_fail 'Missing colon' '{"V","L":2}'
+
+# A bare word that is neither "true", "false" nor a number. This is where
+# "null" ends up.
+check_json_fail 'Unknown literal' '{"V":null,"L":'"$LEAF"'}'
+
+# A ':' with no value after it, so the token where the value belongs is one the
+# object parser has no case for.
+check_json_fail 'Missing value' '{"V":}'
+
+# A ',' with nothing after it, and a value with no ',' before the next key.
+check_json_fail 'Trailing comma in an object' '{"V":2,"L":'"$LEAF"',}'
+check_json_fail 'Missing comma in an object' '{"V":2 "L":'"$LEAF"'}'
+
+# Arrays hold objects and nothing else.
+check_json_fail 'Non-object in an array' \
+	'{"V":2,"L":{"t":"v","w":80,"h":24,"x":0,"y":0,"c":["x"]}}'
+check_json_fail 'Trailing comma in an array' \
+	'{"V":2,"L":{"t":"v","w":80,"h":24,"x":0,"y":0,"c":['"$LEAF"',]}}'
+
+# An empty string is two adjacent quotes with no value token between them,
+# which the string parser does not accept.
+check_json_fail 'Empty string' '{"V":2,"L":""}'
+
+# A number token that strtoll does not consume all of.
+check_json_fail 'Number with trailing characters' '{"V":8a,"L":'"$LEAF"'}'
+
+# Anything after the top level object.
+check_json_fail 'Data after the top level object' '{"V":2,"L":'"$LEAF"'}{}'
+
+# None of the rejections touched the layout.
+must_equal 'Layout after rejected parses' "$(layout L:one)" "$ONE"
+
+# ---------------------------------------------------------------------------
+# Dumping a split.
+
+check_ok new-window -d -t L:2 -n two
+q0=$($TMUX display-message -p -t L:two.0 '#{pane_id}')
+
+# -l 12 gives the new (bottom) pane 12 lines, leaving 11 for the top pane and
+# one for the border between them. With -d the top pane stays active.
+check_ok split-window -d -v -l 12 -t L:two.0
+q1=$($TMUX display-message -p -t L:two.1 '#{pane_id}')
+
+# Nothing has changed the active pane, so the last pane stack is still empty
+# and the bottom pane has neither "a" nor "l".
+must_equal 'Split layout' "$(layout L:two)" \
+	'{"V":2,"L":{"t":"v","w":80,"h":24,"x":0,"y":0,"c":[{"t":"p","w":80,"h":11,"x":0,"y":0,"a":true,"i":0,"I":"%N"},{"t":"p","w":80,"h":12,"x":0,"y":12,"i":1,"I":"%N"}]}}'
+
+# ---------------------------------------------------------------------------
+# The active and last pane keys.
+
+# Selecting the bottom pane makes it active and pushes the top pane onto the
+# last pane stack, where it is at index 0.
+check_ok select-pane -t "$q1"
+must_equal 'Layout after select-pane' "$(layout L:two)" \
+	'{"V":2,"L":{"t":"v","w":80,"h":24,"x":0,"y":0,"c":[{"t":"p","w":80,"h":11,"x":0,"y":0,"l":0,"i":0,"I":"%N"},{"t":"p","w":80,"h":12,"x":0,"y":12,"a":true,"i":1,"I":"%N"}]}}'
+
+# Selecting the top pane again swaps the two keys over. "i" and "I" do not
+# move: they are the pane's position in the window and its id.
+check_ok select-pane -t "$q0"
+SPLIT='{"V":2,"L":{"t":"v","w":80,"h":24,"x":0,"y":0,"c":[{"t":"p","w":80,"h":11,"x":0,"y":0,"a":true,"i":0,"I":"%N"},{"t":"p","w":80,"h":12,"x":0,"y":12,"l":0,"i":1,"I":"%N"}]}}'
+must_equal 'Layout after select-pane back' "$(layout L:two)" "$SPLIT"
+
+# ---------------------------------------------------------------------------
+# The visible layout.
+
+# With nothing zoomed the two layout formats agree.
+#
+# The zoomed case is deliberately not covered here. While a pane is zoomed
+# #{window_layout} dumps the saved (unzoomed) layout and
+# #{window_visible_layout} the zoomed one, but that depends on how zooming
+# stashes the layout root rather than on anything in layout-custom.c.
+must_equal 'Visible layout' "$(visible_layout L:two)" "$SPLIT"
+
+# ---------------------------------------------------------------------------
+# Round trip.
+
+# Make the two panes obviously uneven so that the layout applied in between
+# cannot be mistaken for the saved one. A resize shows up in the dump as the
+# new cell sizes and offsets.
+check_ok resize-pane -t "$q0" -y 5
+saved=$(raw_layout L:two)
+must_equal 'Resized layout' "$(layout L:two)" \
+	'{"V":2,"L":{"t":"v","w":80,"h":24,"x":0,"y":0,"c":[{"t":"p","w":80,"h":5,"x":0,"y":0,"a":true,"i":0,"I":"%N"},{"t":"p","w":80,"h":18,"x":0,"y":6,"l":0,"i":1,"I":"%N"}]}}'
+
+check_ok select-layout -t L:two even-vertical
+must_differ 'Layout after even-vertical' "$(raw_layout L:two)" "$saved"
+
+# Parsing a dump gives back exactly the same dump, pane ids included. The panes
+# go back into the cells that named them: the cells are ordered by "i" and then
+# given the window's panes in order, so a cell dumped with "i":k must come back
+# the k'th.
+check_ok select-layout -t L:two "$saved"
+must_equal 'Round tripped layout' "$(raw_layout L:two)" "$saved"
+
+# ---------------------------------------------------------------------------
+# Parsing a hand-written layout.
+
+# Laid out over several lines to keep it readable; that the whitespace is
+# skipped at all is json.c's business, what matters here is that the cells come
+# out of it in the right shape.
+#
+# "a" and "l" are given on the cells so that the active pane and the last pane
+# stack are pinned by the layout rather than left to whatever a layout that
+# names neither happens to produce.
+check_ok select-layout -t L:two "$(printf '{
+	"V": 2,
+	"L": {
+		"t": "h",
+		"w": 80,
+		"h": 24,
+		"x": 0,
+		"y": 0,
+		"c": [
+			{"t": "p", "w": 30, "h": 24, "x": 0, "y": 0, "a": true, "i": 0, "I": "%s"},
+			{"t": "p", "w": 49, "h": 24, "x": 31, "y": 0, "l": 0, "i": 1, "I": "%s"}
+		]
+	}
+}' "$q0" "$q1")"
+must_equal 'Hand-written layout' "$(layout L:two)" \
+	'{"V":2,"L":{"t":"h","w":80,"h":24,"x":0,"y":0,"c":[{"t":"p","w":30,"h":24,"x":0,"y":0,"a":true,"i":0,"I":"%N"},{"t":"p","w":49,"h":24,"x":31,"y":0,"l":0,"i":1,"I":"%N"}]}}'
+
+# The panes are assigned to the cells in order.
+must_equal 'First pane width' \
+	"$($TMUX display-message -p -t "$q0" '#{pane_width}')" '30'
+must_equal 'Second pane width' \
+	"$($TMUX display-message -p -t "$q1" '#{pane_width}')" '49'
+
+# ---------------------------------------------------------------------------
+# Field order.
+
+# Fields are looked up by key once the object has been parsed, so the order
+# they are written in must give the same layout. Here every object has its keys
+# reversed: "c" comes before "t" and "V" comes after "L", neither of which
+# changes the order they are read in - the cell type is always read before the
+# children and the version before the layout.
+check_ok select-layout -t L:two \
+	'{"L":{"c":[{"I":"'"$q0"'","i":0,"a":true,"y":0,"x":0,"h":8,"w":80,"t":"p"},{"I":"'"$q1"'","i":1,"l":0,"y":9,"x":0,"h":15,"w":80,"t":"p"}],"y":0,"x":0,"h":24,"w":80,"t":"v"},"V":2}'
+must_equal 'Reversed field order' "$(layout L:two)" \
+	'{"V":2,"L":{"t":"v","w":80,"h":24,"x":0,"y":0,"c":[{"t":"p","w":80,"h":8,"x":0,"y":0,"a":true,"i":0,"I":"%N"},{"t":"p","w":80,"h":15,"x":0,"y":9,"l":0,"i":1,"I":"%N"}]}}'
+
+# Keys interleaved rather than simply reversed, with "c" in the middle. This
+# time "a" is on the second cell, so the second pane becomes the active one:
+# which pane is active comes from the layout, while "i" and "I" still come from
+# the window. The first cell names neither "a" nor "l", so its pane is neither
+# active nor on the last pane stack and the dump gives it neither key.
+check_ok select-layout -t L:two \
+	'{"V":2,"L":{"h":24,"c":[{"w":40,"t":"p","y":0,"i":0,"h":24,"I":"'"$q0"'","x":0},{"a":true,"h":24,"I":"'"$q1"'","w":39,"y":0,"t":"p","i":1,"x":41}],"w":80,"y":0,"t":"h","x":0}}'
+must_equal 'Scrambled field order' "$(layout L:two)" \
+	'{"V":2,"L":{"t":"h","w":80,"h":24,"x":0,"y":0,"c":[{"t":"p","w":40,"h":24,"x":0,"y":0,"i":0,"I":"%N"},{"t":"p","w":39,"h":24,"x":41,"y":0,"a":true,"i":1,"I":"%N"}]}}'
+
+# ---------------------------------------------------------------------------
+# The legacy (v1) format.
+
+# The layout just applied, in v1: a left/right cell is written with braces and
+# a top/bottom cell with brackets, and each leaf carries its pane id without
+# the leading %.
+v1body="80x24,0,0{40x24,0,0,${q0#%},39x24,41,0,${q1#%}}"
+
+# A control client that has not asked for new layouts is dumped v1.
+must_equal 'v1 dump' "$(v1_layout L:two)" "$(v1 "$v1body")"
+
+# With the new-layouts flag the same client is dumped v2 instead. The flag is
+# set with "attach -f" rather than refresh-client because refresh-client needs
+# a current client, which a control client that has not attached has not got.
+got=$(printf "display-message -p -t L:two '#{window_layout}'\n" |
+	$TMUX -C attach -f new-layouts -t L 2>&1 | grep -v '^%')
+must_contain 'v2 dump for control client' "$got" '{"V":2,"L":'
+
+# A v1 layout with a correct checksum is parsed, and dumping v1 again gives
+# back the same string. That is the whole of what v1 carries: the cells take
+# the sizes and offsets from the body, and the panes are assigned to them in
+# order, which is what puts the same two ids back in the same two places. It is
+# checked in v1 rather than against a v2 dump so that nothing v1 has no opinion
+# on - the active pane, the last pane stack, the pane index - comes into it.
+v1vsplit="80x24,0,0[80x11,0,0,${q0#%},80x12,0,12,${q1#%}]"
+check_ok select-layout -t L:two "$(v1 "$v1vsplit")"
+must_equal 'v1 round trip' "$(v1_layout L:two)" "$(v1 "$v1vsplit")"
+
+# v1 names no active pane, last pane or z-index and must disturb none of them.
+# Applying the v1 form of the layout the window already has therefore leaves
+# even the v2 dump the same byte for byte, last pane stack included.
+check_ok select-pane -t "$q1"
+check_ok select-pane -t "$q0"
+before=$(raw_layout L:two)
+check_ok select-layout -t L:two "$(v1 "$v1vsplit")"
+must_equal 'v1 leaves the active and last panes alone' \
+	"$(raw_layout L:two)" "$before"
+
+# A v1 layout with more cells than the window has panes is trimmed like any
+# other: the bottom right cell is closed and the cell above it takes its eight
+# rows and the border between them, leaving 16. Pane ids in a v1 body are not
+# used to place panes, so the third cell can carry any id.
+v1three="80x24,0,0[80x7,0,0,${q0#%},80x7,0,8,${q1#%},80x8,0,16,999]"
+check_ok select-layout -t L:two "$(v1 "$v1three")"
+must_equal 'v1 layout trimmed' "$(v1_layout L:two)" \
+	"$(v1 "80x24,0,0[80x7,0,0,${q0#%},80x16,0,8,${q1#%}]")"
+
+# ---------------------------------------------------------------------------
+# Pane assignment order.
+
+# "i" is what decides which pane goes into which cell: the cells are ordered by
+# it and then handed the window's panes in order, so the cell with "i":0 takes
+# the first pane of the window wherever that cell sits in the layout. Here the
+# cells are written the other way round from their indexes - the first cell in
+# the string is "i":1 and the second "i":0 - so the first pane of the window
+# has to come out in the second cell.
+#
+# Every other layout above lists its cells in the same order as their indexes,
+# which is the order the tree is walked in, so this is the only check that can
+# tell the two apart.
+check_ok select-layout -t L:two \
+	'{"V":2,"L":{"t":"v","w":80,"h":24,"x":0,"y":0,"c":[{"t":"p","w":80,"h":8,"x":0,"y":0,"i":1,"I":"'"$q1"'"},{"t":"p","w":80,"h":15,"x":0,"y":9,"i":0,"I":"'"$q0"'"}]}}'
+must_equal 'First pane height' \
+	"$($TMUX display-message -p -t "$q0" '#{pane_height}')" '15'
+must_equal 'Second pane height' \
+	"$($TMUX display-message -p -t "$q1" '#{pane_height}')" '8'
+
+# So the dump carries the two ids the other way round from every dump above,
+# and with them their indexes, which are the panes' positions in the window and
+# have not moved. Neither cell named an active or last pane, so the pane that
+# was active still is - it is now the one in the second cell.
+swapped='{"V":2,"L":{"t":"v","w":80,"h":24,"x":0,"y":0,"c":[{"t":"p","w":80,"h":8,"x":0,"y":0,"i":1,"I":"'"$q1"'"},{"t":"p","w":80,"h":15,"x":0,"y":9,"a":true,"i":0,"I":"'"$q0"'"}]}}'
+must_equal 'Layout with the panes swapped' "$(raw_layout L:two)" "$swapped"
+
+# And that dump round trips, indexes out of order and all.
+check_ok select-layout -t L:two "$swapped"
+must_equal 'Round tripped swapped layout' "$(raw_layout L:two)" "$swapped"
+
+# ---------------------------------------------------------------------------
+# Cells that name no active or last pane.
+
+# "a" and "l" are the only things that decide which pane is active and what is
+# on the last pane stack, so a layout naming neither leaves the active pane
+# where it was and empties the stack. Here the first pane of the window is
+# active and the second is at index 0 of the stack beforehand; afterwards the
+# first pane is still active and the stack is empty, so the second pane has no
+# "l".
+check_ok select-pane -t "$q1"
+check_ok select-pane -t "$q0"
+check_ok select-layout -t L:two \
+	'{"V":2,"L":{"t":"v","w":80,"h":24,"x":0,"y":0,"c":[{"t":"p","w":80,"h":9,"x":0,"y":0,"i":0,"I":"'"$q0"'"},{"t":"p","w":80,"h":14,"x":0,"y":10,"i":1,"I":"'"$q1"'"}]}}'
+must_equal 'Layout naming no active pane' "$(layout L:two)" \
+	'{"V":2,"L":{"t":"v","w":80,"h":24,"x":0,"y":0,"c":[{"t":"p","w":80,"h":9,"x":0,"y":0,"a":true,"i":0,"I":"%N"},{"t":"p","w":80,"h":14,"x":0,"y":10,"i":1,"I":"%N"}]}}'
+
+# "a" may be given as false, which says the same as leaving it out: this pane
+# is not the active one. A layout where every cell says so names no active pane
+# at all and so leaves the active pane alone, exactly as the layout above did.
+check_ok select-layout -t L:two \
+	'{"V":2,"L":{"t":"v","w":80,"h":24,"x":0,"y":0,"c":[{"t":"p","w":80,"h":10,"x":0,"y":0,"a":false,"i":0,"I":"'"$q0"'"},{"t":"p","w":80,"h":13,"x":0,"y":11,"a":false,"i":1,"I":"'"$q1"'"}]}}'
+must_equal 'Layout with only false active panes' "$(layout L:two)" \
+	'{"V":2,"L":{"t":"v","w":80,"h":24,"x":0,"y":0,"c":[{"t":"p","w":80,"h":10,"x":0,"y":0,"a":true,"i":0,"I":"%N"},{"t":"p","w":80,"h":13,"x":0,"y":11,"i":1,"I":"%N"}]}}'
+
+# ---------------------------------------------------------------------------
+# Failures.
+#
+# Each of these is a different reason for a layout to be rejected, but only the
+# rejection itself is checked; the message that comes back with it is not.
+
+# check_layout_fail $layout
+#
+# select-layout must reject $layout.
+check_layout_fail()
+{
+	check_fail select-layout -t L:two "$1"
+}
+
+# A rejected layout must leave the window alone, whatever it was.
+unchanged=$(raw_layout L:two)
+
+# Not JSON and not a checksum.
+check_layout_fail 'garbage'
+
+# A v1 body with its checksum left off, and a string of nothing but hex digits.
+# A v1 header is four hex digits and a comma; neither of these has one, so there
+# is no header and nothing to check a body against.
+check_layout_fail '80x24,0,0'
+check_layout_fail 'ab'
+
+# A v1 header with the checksum of a different body.
+good=$(v1 '80x24,0,0')
+check_layout_fail "${good%%,*},80x24,0,1"
+
+# A correct checksum over a body that is not a layout: a cell with no offsets,
+# and a top to bottom cell closed with '}' instead of ']'. layout_construct_v1
+# returns NULL for both.
+check_layout_fail "$(v1 '80x24')"
+check_layout_fail "$(v1 '80x24,0,0[80x11,0,0,80x12,0,12}')"
+
+# Fewer cells than the window has panes; unlike the other way around this
+# cannot be fixed up.
+check_layout_fail '{"V":2,"L":{"t":"p","w":80,"h":24,"x":0,"y":0,"i":0,"I":"'"$q0"'"}}'
+
+# The children of a top to bottom cell must all be the width of their parent.
+check_layout_fail \
+	'{"V":2,"L":{"t":"v","w":80,"h":24,"x":0,"y":0,"c":[{"t":"p","w":80,"h":11,"x":0,"y":0,"i":0,"I":"'"$q0"'"},{"t":"p","w":40,"h":12,"x":0,"y":12,"i":1,"I":"'"$q1"'"}]}}'
+
+# The rest are valid JSON, so it is layout_parse_json() and
+# layout_parse_json_layout() doing the rejecting rather than json.c. Each of
+# them is a layout that would be applied but for the one thing being checked.
+
+# Two root cells.
+check_layout_fail \
+	'{"V":2,"L":{"t":"p","w":80,"h":24,"x":0,"y":0,"i":0,"I":"'"$q0"'"},"L":{"t":"p","w":80,"h":24,"x":0,"y":0,"i":0,"I":"'"$q0"'"}}'
+
+# A missing "y". A cell needs all four of "w", "h", "x" and "y".
+check_layout_fail '{"V":2,"L":{"t":"p","w":80,"h":24,"x":0,"i":0,"I":"'"$q0"'"}}'
+
+# Cell sizes are bounded below by one column or row and above by 10000 of
+# either. Both cases are otherwise complete two cell layouts, so the size is
+# the only thing wrong with them.
+check_layout_fail \
+	'{"V":2,"L":{"t":"v","w":80,"h":24,"x":0,"y":0,"c":[{"t":"p","w":80,"h":11,"x":0,"y":0,"i":0,"I":"'"$q0"'"},{"t":"p","w":0,"h":12,"x":0,"y":12,"i":1,"I":"'"$q1"'"}]}}'
+check_layout_fail \
+	'{"V":2,"L":{"t":"v","w":80,"h":24,"x":0,"y":0,"c":[{"t":"p","w":80,"h":11,"x":0,"y":0,"i":0,"I":"'"$q0"'"},{"t":"p","w":80,"h":10001,"x":0,"y":12,"i":1,"I":"'"$q1"'"}]}}'
+
+# An unknown cell type: only "h", "v" and "p" exist.
+check_layout_fail '{"V":2,"L":{"t":"q","w":80,"h":24,"x":0,"y":0}}'
+
+# A pane cell needs "i", its pane index. It is "i" that says which pane goes in
+# the cell; "I" is the pane id the cell was dumped with and is not read back.
+check_layout_fail '{"V":2,"L":{"t":"p","w":80,"h":24,"x":0,"y":0,"I":"'"$q0"'"}}'
+
+# A node cell must have more than one child and a leaf cell must have none. A
+# node is written with no "c" at all, with an empty one and with a single child.
+check_layout_fail '{"V":2,"L":{"t":"v","w":80,"h":24,"x":0,"y":0}}'
+check_layout_fail '{"V":2,"L":{"t":"v","w":80,"h":24,"x":0,"y":0,"c":[]}}'
+check_layout_fail \
+	'{"V":2,"L":{"t":"v","w":80,"h":24,"x":0,"y":0,"c":[{"t":"p","w":80,"h":24,"x":0,"y":0,"i":0,"I":"'"$q0"'"}]}}'
+check_layout_fail \
+	'{"V":2,"L":{"t":"p","w":80,"h":24,"x":0,"y":0,"i":0,"I":"'"$q0"'","c":[{"t":"p","w":80,"h":24,"x":0,"y":0,"i":1,"I":"'"$q1"'"}]}}'
+
+# Only one cell may be the active pane.
+check_layout_fail \
+	'{"V":2,"L":{"t":"v","w":80,"h":24,"x":0,"y":0,"c":[{"t":"p","w":80,"h":11,"x":0,"y":0,"a":true,"i":0,"I":"'"$q0"'"},{"t":"p","w":80,"h":12,"x":0,"y":12,"a":true,"i":1,"I":"'"$q1"'"}]}}'
+
+# The same rejections apply whatever order the fields are written in: a leaf
+# with children when "c" comes first, and a node with no children and a bad cell
+# type when "t" comes last.
+check_layout_fail \
+	'{"V":2,"L":{"c":[{"t":"p","w":80,"h":24,"x":0,"y":0,"i":1,"I":"'"$q1"'"}],"t":"p","w":80,"h":24,"x":0,"y":0,"i":0,"I":"'"$q0"'"}}'
+check_layout_fail '{"V":2,"L":{"w":80,"h":24,"x":0,"y":0,"t":"v"}}'
+check_layout_fail '{"V":2,"L":{"w":80,"h":24,"x":0,"y":0,"t":"q"}}'
+
+# A child that fails after a sibling has already been parsed and added to the
+# parent. This is the case the cleanup at the end of layout_parse_json_layout
+# exists for: the children built so far have to be freed along with the parent
+# that is never returned. The second child has no "y".
+check_layout_fail \
+	'{"V":2,"L":{"c":[{"t":"p","w":80,"h":11,"x":0,"y":0,"i":0,"I":"'"$q0"'"},{"t":"p","w":80,"h":12,"x":0,"i":1,"I":"'"$q1"'"}],"t":"v","w":80,"h":24,"x":0,"y":0}}'
+
+# No root cell at all. Every other rejection above comes from a cell that
+# failed to parse; this one is the check for "L" itself.
+check_layout_fail '{"V":2}'
+
+# The wrong version, with "V" before and after "L". Fields are looked up by
+# key, so the version is read before the layout either way and the position of
+# "V" in the string makes no difference.
+check_layout_fail '{"V":1,"L":{"t":"p","w":80,"h":24,"x":0,"y":0,"i":0,"I":"'"$q0"'"}}'
+check_layout_fail '{"L":{"t":"p","w":80,"h":24,"x":0,"y":0,"i":0,"I":"'"$q0"'"},"V":1}'
+
+# None of that touched the layout.
+must_equal 'Layout after failures' "$(raw_layout L:two)" "$unchanged"
+
+# ---------------------------------------------------------------------------
+# Floating panes.
+
+check_ok new-window -d -t L:3 -n float
+check_ok select-window -t L:float
+check_ok new-pane -d -x 20 -y 6 -X 8 -Y 3 'sleep 100'
+check_ok new-pane -d -x 30 -y 8 -X 30 -Y 10 'sleep 100'
+
+# The tiled pane and the two floating ones. A floating pane goes on the end of
+# the window's pane list, so the pane indexes are in the order the panes were
+# made whatever order their cells end up in.
+f0=$($TMUX display-message -p -t L:float.0 '#{pane_id}')
+fa=$($TMUX display-message -p -t L:float.1 '#{pane_id}')
+fb=$($TMUX display-message -p -t L:float.2 '#{pane_id}')
+
+# A floating cell is dumped with its z-index, which is what marks it as
+# floating when the layout is parsed back. Two of them, so that there is an
+# order between them to get wrong: the newer floating pane is in front, and a
+# cell's "z" is its place in that order counting from the front.
+floating=$(raw_layout L:float)
+must_contain 'Floating layout front z-index' "$floating" '"z":0'
+must_contain 'Floating layout back z-index' "$floating" '"z":1'
+
+# Each floating cell goes in after the cell of the pane that was current when
+# it was made, which is the tiled pane both times, so the newer floating cell
+# is written before the older one while its pane comes after in the window.
+# The dump therefore has its cells in one order and their indexes in another,
+# and only comes back the same if the panes go by index.
+check_ok select-layout -t L:float "$floating"
+must_equal 'Floating layout after round trip' "$(raw_layout L:float)" "$floating"
+
+# ---------------------------------------------------------------------------
+# Floating panes and the legacy (v1) format.
+#
+# v1 has no way to write a floating pane down, so the two formats cannot say the
+# same thing about a window that has one. Dumping v1 takes a copy of the layout,
+# deletes the floating cells from the copy and dumps what is left; parsing v1
+# rearranges the tiled panes and leaves the floating ones where they are. None
+# of this is reached above: every v1 check so far runs on a window that has no
+# floating panes, and every floating pane check so far is in v2.
+
+# float_state $target
+#
+# Everything about a floating pane that a v1 layout has no way to carry, so that
+# applying one can be checked against all of it at once.
+float_state()
+{
+	$TMUX display-message -p -t "$1" \
+		'#{pane_floating_flag} #{pane_width}x#{pane_height} #{pane_left},#{pane_top} #{pane_z}'
+}
+
+# Deleting both floating cells from the copy leaves the root node with a single
+# child, and a node with a single child collapses into it, so the root of the
+# copy is the tiled cell and the dump is that cell on its own filling the
+# window.
+must_equal 'v1 dump with floating panes' "$(v1_layout L:float)" \
+	"$(v1 "80x24,0,0,${f0#%}")"
+
+# The cells are deleted from the copy, so the window itself comes through a v1
+# dump untouched - floating panes, z-indexes and all.
+must_equal 'Layout after a v1 dump' "$(raw_layout L:float)" "$floating"
+
+# The same with a split, where deleting the floating cell still leaves two
+# children behind and the node it was in does not collapse.
+check_ok new-window -d -t L:4 -n mixed
+m0=$($TMUX display-message -p -t L:mixed.0 '#{pane_id}')
+check_ok split-window -d -v -l 12 -t L:mixed.0
+m1=$($TMUX display-message -p -t L:mixed.1 '#{pane_id}')
+check_ok new-pane -d -x 20 -y 6 -X 8 -Y 3 -t L:mixed.0 'sleep 100'
+mf=$($TMUX display-message -p -t L:mixed.2 '#{pane_id}')
+
+# A floating pane takes no space from the tiled layout, so the two tiled cells
+# are the same 11 and 12 rows the split gave them.
+must_equal 'v1 dump with a split and a floating pane' "$(v1_layout L:mixed)" \
+	"$(v1 "80x24,0,0[80x11,0,0,${m0#%},80x12,0,12,${m1#%}]")"
+
+# A v1 layout applied to a window that has a floating pane rearranges the tiled
+# panes and must leave the floating one exactly as it was: v1 names no floating
+# pane, so there is nothing in it for one to be changed by. The top pane goes
+# from 11 rows to 7 and the bottom one from 12 to 16.
+v1mixed="80x24,0,0[80x7,0,0,${m0#%},80x16,0,8,${m1#%}]"
+mfbefore=$(float_state "$mf")
+check_ok select-layout -t L:mixed "$(v1 "$v1mixed")"
+must_equal 'v1 layout with a floating pane' "$(v1_layout L:mixed)" \
+	"$(v1 "$v1mixed")"
+must_equal 'Floating pane after a v1 layout' "$(float_state "$mf")" "$mfbefore"
+must_equal 'Panes after a v1 layout' \
+	"$($TMUX display-message -p -t L:mixed '#{window_panes}')" '3'
+
+# When the tiled layout a v1 string names is a single cell there is no node in
+# the new layout for the floating cells to go back into, so one is made: the
+# root cell is replaced by a top to bottom node holding it and the floating
+# cells go on the end. Nothing else here reaches that.
+fabefore=$(float_state "$fa")
+fbbefore=$(float_state "$fb")
+check_ok select-layout -t L:float "$(v1 "80x24,0,0,${f0#%}")"
+must_equal 'v1 single cell layout with floating panes' "$(v1_layout L:float)" \
+	"$(v1 "80x24,0,0,${f0#%}")"
+must_equal 'Front floating pane after a v1 layout' "$(float_state "$fb")" \
+	"$fbbefore"
+must_equal 'Back floating pane after a v1 layout' "$(float_state "$fa")" \
+	"$fabefore"
+must_equal 'Panes after a v1 single cell layout' \
+	"$($TMUX display-message -p -t L:float '#{window_panes}')" '3'
+
+# Adjacent subtrees containing only floating panes used to be a distinct case:
+# dumping v1 made a copy of the v2 tree and deleted floating cells from the
+# copy, but deleting the last floating cell in the first subtree collapsed the
+# parent and could leave the outer traversal holding a stale pointer to the
+# second subtree.
+check_ok new-window -d -t L:5 -n nested
+n0=$($TMUX display-message -p -t L:nested.0 '#{pane_id}')
+check_ok split-window -d -v -l 12 -t L:nested.0
+n1=$($TMUX display-message -p -t L:nested.1 '#{pane_id}')
+check_ok split-window -d -v -l 6 -t L:nested.1
+n2=$($TMUX display-message -p -t L:nested.2 '#{pane_id}')
+check_ok split-window -d -v -l 3 -t L:nested.2
+n3=$($TMUX display-message -p -t L:nested.3 '#{pane_id}')
+check_ok split-window -d -v -l 2 -t L:nested.3
+n4=$($TMUX display-message -p -t L:nested.4 '#{pane_id}')
+check_ok select-layout -t L:nested \
+	'{"V":2,"L":{"t":"v","w":80,"h":24,"x":0,"y":0,"c":[{"t":"h","w":30,"h":10,"x":0,"y":0,"c":[{"t":"p","w":10,"h":5,"x":2,"y":2,"i":0,"z":0},{"t":"p","w":12,"h":6,"x":5,"y":5,"i":1,"z":1}]},{"t":"h","w":30,"h":10,"x":0,"y":0,"c":[{"t":"p","w":14,"h":7,"x":8,"y":8,"i":2,"z":2},{"t":"p","w":16,"h":8,"x":11,"y":11,"i":3,"z":3}]},{"t":"p","w":80,"h":24,"x":0,"y":0,"i":4}]}}'
+must_equal 'v1 dump with nested floating-only subtrees' \
+	"$(v1_layout L:nested)" "$(v1 "80x24,0,0,${n4#%}")"
+check_ok kill-window -t L:nested
+
+# ---------------------------------------------------------------------------
+# A window with no tiled panes.
+#
+# Killing the last tiled pane of a window that has floating panes does not kill
+# the window: that only happens when the pane being killed is the last one
+# counting the floating ones. What is left is a window whose layout root is
+# either a floating cell on its own, or a node holding nothing but floating
+# cells, depending on how many are left. v1 has no way to write either down, so
+# it must not try: a layout with no tiled panes in it produces no v1 dump at
+# all, and #{window_layout} comes back empty for a client being sent v1. What v2
+# makes of such a window is a separate question and is not checked here.
+#
+# A dead server dumps nothing either, so the checks below have to establish that
+# the server is still there before an empty dump is allowed to mean anything.
+
+# no_hang $cmd...
+#
+# Run a command whose result is not being checked, but which has to come back:
+# only the server surviving it is checked afterwards, and a server wedged rather
+# than killed would otherwise show up as the test never finishing.
+no_hang()
+{
+	if command -v timeout >/dev/null 2>&1; then
+		timeout 10 "$@" >/dev/null 2>&1
+	else
+		"$@" >/dev/null 2>&1
+	fi
+	return 0
+}
+
+# One floating pane left. The node it and the tiled cell were in is down to a
+# single child, so it collapses and the floating cell becomes the root.
+check_ok new-window -d -t L:5 -n gone1
+g0=$($TMUX display-message -p -t L:gone1.0 '#{pane_id}')
+check_ok new-pane -d -x 20 -y 6 -X 8 -Y 3 -t L:gone1.0 'sleep 100'
+check_ok kill-pane -t "$g0"
+must_equal 'Panes left with one floating pane' \
+	"$($TMUX display-message -p -t L:gone1 '#{window_panes}')" '1'
+
+# The floating cell is the root and there is nothing tiled under it, so there is
+# no v1 dump to make. In particular the floating cell must not be written out on
+# its own, which would be a layout claiming the window is the size and position
+# of the floating pane with no pane in it at all.
+got=$(v1_layout L:gone1)
+check_ok display-message -p alive
+must_equal 'v1 dump with one floating pane and no tiled panes' "$got" ''
+
+# Two floating panes left, so the node keeps two children, does not collapse,
+# and stays the root with nothing but floating cells in it.
+check_ok new-window -d -t L:6 -n gone2
+h0=$($TMUX display-message -p -t L:gone2.0 '#{pane_id}')
+check_ok new-pane -d -x 20 -y 6 -X 8 -Y 3 -t L:gone2.0 'sleep 100'
+check_ok new-pane -d -x 30 -y 8 -X 30 -Y 10 -t L:gone2.0 'sleep 100'
+check_ok kill-pane -t "$h0"
+must_equal 'Panes left with two floating panes' \
+	"$($TMUX display-message -p -t L:gone2 '#{window_panes}')" '2'
+
+# The node is the root this time rather than the floating cell, but it has no
+# tiled cell anywhere under it either, so there is still no v1 dump to make -
+# and making one must not take the server with it.
+got=$(v1_layout L:gone2)
+check_ok display-message -p alive
+must_equal 'v1 dump with two floating panes and no tiled panes' "$got" ''
+
+# Nor must parsing a v1 layout against it. There is no tiled pane for the
+# layout to name, so whether it is applied or rejected is the format's business;
+# it just has to be one of the two.
+no_hang $TMUX select-layout -t L:gone2 "$(v1 '80x24,0,0,999')"
+check_ok display-message -p alive
+
+check_ok kill-window -t L:gone1
+check_ok kill-window -t L:gone2
+
+# ---------------------------------------------------------------------------
+# Control mode notifications.
+#
+# %layout-change is what a control client actually reads a layout from, and it
+# carries both #{window_layout} and #{window_visible_layout}. Its template is
+# expanded once per client (control-notify.c), so two clients watching the same
+# window must be told about the same change in different formats: v1 for the
+# one that has not asked for new layouts, v2 for the one that has.
+#
+# The dumps above go through "-C display-message", which only ever reaches the
+# format callbacks for the client asking. This needs clients that stay
+# attached while something else changes the layout, so they go on the end of
+# fifos and the change is made from outside.
+
+DIR=$(mktemp -d) || fail 'Could not make a temporary directory'
+OLDIN="$DIR/old-in"
+OLDOUT="$DIR/old-out"
+NEWIN="$DIR/new-in"
+NEWOUT="$DIR/new-out"
+OLDPID=
+NEWPID=
+
+cleanup()
+{
+	[ -n "$OLDPID" ] && kill "$OLDPID" 2>/dev/null
+	[ -n "$NEWPID" ] && kill "$NEWPID" 2>/dev/null
+	$TMUX kill-server 2>/dev/null
+	rm -rf "$DIR"
+}
+trap cleanup EXIT
+
+# wait_for $file $text
+#
+# Wait for $text to appear in a control client's output.
+wait_for()
+{
+	i=0
+	while [ "$i" -lt 6 ]; do
+		grep -F -- "$2" "$1" >/dev/null 2>&1 && return 0
+		sleep 1
+		i=$((i + 1))
+	done
+	echo "missing from $1: $2" >&2
+	cat "$1" >&2
+	return 1
+}
+
+mkfifo "$OLDIN" "$NEWIN" || fail 'Could not make the control client fifos'
+: >"$OLDOUT"
+: >"$NEWOUT"
+
+$TMUX -C attach -t L <"$OLDIN" >"$OLDOUT" 2>&1 &
+OLDPID=$!
+exec 4>"$OLDIN"
+$TMUX -C attach -f new-layouts -t L <"$NEWIN" >"$NEWOUT" 2>&1 &
+NEWPID=$!
+exec 5>"$NEWIN"
+
+# Both clients have to be attached before the layout changes, or they miss the
+# notification entirely.
+printf 'display-message -p ready\n' >&4
+printf 'display-message -p ready\n' >&5
+wait_for "$OLDOUT" ready || fail 'Control client without new-layouts did not attach'
+wait_for "$NEWOUT" ready || fail 'Control client with new-layouts did not attach'
+
+wid=$($TMUX display-message -p -t L:two '#{window_id}')
+
+# One layout change, made by a third client so that neither of the two is the
+# one running the command. 8 lines for the top pane leaves 15 for the bottom
+# and one for the border.
+check_ok resize-pane -t "$q0" -y 8
+
+# Nothing is zoomed, so both fields of the notification carry the same layout.
+# The v2 one is compared against the dump rather than a literal so that it is
+# the two formats being checked and not the geometry again.
+v2now=$(raw_layout L:two)
+v1now=$(v1 "80x24,0,0[80x8,0,0,${q0#%},80x15,0,9,${q1#%}]")
+wait_for "$NEWOUT" "%layout-change $wid $v2now $v2now " ||
+	fail 'No v2 %layout-change for the client with new-layouts'
+wait_for "$OLDOUT" "%layout-change $wid $v1now $v1now " ||
+	fail 'No v1 %layout-change for the client without new-layouts'
+
+# How many notifications one layout change produces, which differs by format
+# on purpose. cmd_select_layout_exec() fires window-layout-changed for any
+# layout it applies, and layout_parse() fires it again for a v1 one, so v1
+# arrives twice - which is what master does for every layout, and what control
+# clients written against it expect. v2 is new and has no such clients, so it
+# gets the single notification. Counting the delta rather than the total, with
+# a settle in between, keeps this independent of what has already been sent.
+n1=$(grep -c "%layout-change $wid " "$OLDOUT")
+check_ok select-layout -t L:two \
+	'{"V":2,"L":{"t":"v","w":80,"h":24,"x":0,"y":0,"c":[{"t":"p","w":80,"h":9,"x":0,"y":0,"i":0,"I":"'"$q0"'"},{"t":"p","w":80,"h":14,"x":0,"y":10,"i":1,"I":"'"$q1"'"}]}}'
+sleep 2
+n2=$(grep -c "%layout-change $wid " "$OLDOUT")
+must_equal 'Notifications for a v2 layout' "$((n2 - n1))" '1'
+
+check_ok select-layout -t L:two "$(v1 "$v1vsplit")"
+sleep 2
+n3=$(grep -c "%layout-change $wid " "$OLDOUT")
+must_equal 'Notifications for a v1 layout' "$((n3 - n2))" '2'
+
+# And the client that did not ask for new layouts must never have been sent
+# one, in that notification or any other.
+grep -F '{"V":2,' "$OLDOUT" >/dev/null 2>&1 &&
+	fail 'Control client without new-layouts was sent a v2 layout'
+
+if [ "$($TMUX display-message -p alive 2>&1)" != "alive" ]; then
+	echo "Server died." >&2
+	exit 1
+fi
+
+$TMUX kill-server 2>/dev/null
+exit 0

regress/layout-nesting-limit.sh

@@ -0,0 +1,77 @@
+#!/bin/sh
+
+# Version 1 layouts must reject excessive nesting without losing the session or
+# changing its layout. Check both split types and the depth limit boundary.
+
+PATH=/bin:/usr/bin
+TERM=screen
+export PATH TERM
+
+[ -z "$TEST_TMUX" ] && TEST_TMUX=$(readlink -f ../tmux)
+DIR=$(mktemp -d) || exit 1
+TMUX="$TEST_TMUX -S$DIR/socket -f/dev/null"
+
+fail()
+{
+	echo "$*" >&2
+	exit 1
+}
+
+cleanup()
+{
+	$TMUX kill-server 2>/dev/null
+	rm -rf "$DIR"
+}
+trap cleanup 0
+trap 'exit 1' 1 2 15
+
+# Generate a checksum-valid v1 layout with one child in every nested group.
+layout()
+{
+	awk -v depth="$1" -v open="$2" 'BEGIN {
+		closing = (open == "{" ? "}" : "]")
+		body = ""
+		for (i = 0; i < depth; i++)
+			body = body "1x1,0,0" open
+		body = body "1x1,0,0"
+		for (i = 0; i < depth; i++)
+			body = body closing
+
+		ord["0"] = 48; ord["1"] = 49; ord["x"] = 120
+		ord[","] = 44; ord["{"] = 123; ord["}"] = 125
+		ord["["] = 91; ord["]"] = 93
+		csum = 0
+		for (i = 1; i <= length(body); i++) {
+			c = substr(body, i, 1)
+			bit = csum % 2
+			csum = int(csum / 2) + bit * 32768
+			csum = (csum + ord[c]) % 65536
+		}
+		printf "%04x,%s", csum, body
+	}'
+}
+
+$TMUX new-session -d -s deep -x80 -y24 'exec sleep 100' || exit 1
+
+for open in '{' '['; do
+	# A valid checksum and nesting up to the limit must still be accepted.
+	value=$(layout 1000 "$open") || fail "could not generate layout"
+	$TMUX select-layout -t deep "$value" ||
+		fail "layout at the depth limit was rejected ($open)"
+	before=$($TMUX display-message -p -t deep \
+	    '#{pane_id} #{pane_width} #{pane_height} #{window_layout}') || exit 1
+
+	for depth in 1001 1500; do
+		value=$(layout "$depth" "$open") || fail "could not generate layout"
+		$TMUX select-layout -t deep "$value" >/dev/null 2>&1 &&
+			fail "excessive nesting was accepted ($open, $depth)"
+		$TMUX has-session -t deep ||
+			fail "server died on excessive nesting ($open, $depth)"
+		after=$($TMUX display-message -p -t deep \
+		    '#{pane_id} #{pane_width} #{pane_height} #{window_layout}') || exit 1
+		[ "$before" = "$after" ] ||
+			fail "pane or layout changed after rejection ($open, $depth)"
+	done
+done
+
+exit 0

regress/layout-set.sh

@@ -0,0 +1,126 @@
+#!/bin/sh
+
+# Exercise every predefined layout, next/previous cycling, lookup and restore
+# paths, one-pane early returns, minimum-size handling and floating panes.
+
+PATH=/bin:/usr/bin
+TERM=screen
+export PATH TERM
+
+[ -z "$TEST_TMUX" ] && TEST_TMUX=$(readlink -f ../tmux)
+DIR=$(mktemp -d) || exit 1
+TMUX_TMPDIR=$DIR
+export TMUX_TMPDIR
+TMUX="$TEST_TMUX -Ltest$$ -f/dev/null"
+SEEN="$DIR/layouts"
+
+fail()
+{
+	echo "$*" >&2
+	exit 1
+}
+
+cleanup()
+{
+	$TMUX kill-server 2>/dev/null
+	rm -rf "$DIR"
+}
+trap cleanup 0 1 15
+
+layout()
+{
+	$TMUX display-message -p -t layouts:many '#{window_layout}'
+}
+
+check_layout()
+{
+	name=$1
+	$TMUX select-layout -t layouts:many "$name" ||
+		fail "select-layout $name failed"
+	value=$(layout)
+	[ -n "$value" ] || fail "$name produced an empty layout"
+	if grep -Fxq "$value" "$SEEN"; then
+		fail "$name produced the same layout as an earlier preset"
+	fi
+	printf '%s\n' "$value" >>"$SEEN"
+	[ "$($TMUX list-panes -t layouts:many -F x | wc -l)" -eq 5 ] ||
+		fail "$name lost a pane"
+	[ "$($TMUX list-panes -t layouts:many -F '#{pane_floating_flag}' | \
+	    grep -c '^1$')" -eq 1 ] || fail "$name did not preserve the floating pane"
+}
+
+$TMUX new-session -d -s layouts -n many -x100 -y40 'exec sleep 100' || exit 1
+$TMUX set-option -g window-size manual || exit 1
+$TMUX split-window -d -h -t layouts:many 'exec sleep 100' || exit 1
+$TMUX split-window -d -v -t layouts:many 'exec sleep 100' || exit 1
+$TMUX split-window -d -h -t layouts:many 'exec sleep 100' || exit 1
+floating=$($TMUX new-pane -dP -F '#{pane_id}' -t layouts:many \
+    -x20 -y8 -X10 -Y5 'exec sleep 100') || exit 1
+: >"$SEEN"
+
+# Options exercise percentage and explicit secondary-size calculations.
+$TMUX set-option -w -t layouts:many main-pane-height 30% || exit 1
+$TMUX set-option -w -t layouts:many other-pane-height 12 || exit 1
+$TMUX set-option -w -t layouts:many main-pane-width 35% || exit 1
+$TMUX set-option -w -t layouts:many other-pane-width 20 || exit 1
+
+for name in even-horizontal even-vertical main-horizontal \
+    main-horizontal-mirrored main-vertical main-vertical-mirrored tiled; do
+	check_layout "$name"
+done
+
+# Exact and unique-prefix lookup work; ambiguous and invalid names fail.
+$TMUX select-layout -t layouts:many even-h || fail "unique layout prefix failed"
+$TMUX select-layout -t layouts:many main >/dev/null 2>&1 &&
+	fail "ambiguous layout prefix succeeded"
+$TMUX select-layout -t layouts:many no-such-layout >/dev/null 2>&1 &&
+	fail "invalid layout name succeeded"
+
+# Cycle through all layouts in both directions, including wraparound. The
+# aliases and select-layout flags share layout_set_next/previous.
+first=$(layout)
+i=0
+while [ "$i" -lt 7 ]; do
+	$TMUX next-layout -t layouts:many || exit 1
+	i=$((i + 1))
+done
+[ "$(layout)" = "$first" ] || fail "next-layout did not wrap"
+i=0
+while [ "$i" -lt 7 ]; do
+	$TMUX previous-layout -t layouts:many || exit 1
+	i=$((i + 1))
+done
+[ "$(layout)" = "$first" ] || fail "previous-layout did not wrap"
+$TMUX select-layout -t layouts:many -n || exit 1
+$TMUX select-layout -t layouts:many -p || exit 1
+
+# No argument reapplies the last preset; -o restores the previous layout; -E
+# spreads the current cell without changing the pane set.
+$TMUX kill-pane -t "$floating" || exit 1
+$TMUX select-layout -t layouts:many tiled || exit 1
+tiled=$(layout)
+$TMUX select-layout -t layouts:many even-horizontal || exit 1
+$TMUX select-layout -t layouts:many -o || exit 1
+[ "$(layout)" = "$tiled" ] || fail "select-layout -o did not restore layout"
+$TMUX select-layout -t layouts:many || exit 1
+$TMUX select-layout -t layouts:many -E || exit 1
+
+# Each arranger has a deliberate one-pane early return.
+$TMUX new-window -d -t layouts: -n one 'exec sleep 100' || exit 1
+one=$($TMUX display-message -p -t layouts:one '#{window_layout}')
+for name in even-horizontal even-vertical main-horizontal \
+    main-horizontal-mirrored main-vertical main-vertical-mirrored tiled; do
+	$TMUX select-layout -t layouts:one "$name" || exit 1
+	[ "$($TMUX display-message -p -t layouts:one '#{window_layout}')" = "$one" ] ||
+		fail "$name changed a one-pane layout"
+done
+
+# Force the minimum-size paths without requiring a terminal client.
+$TMUX resize-window -t layouts:many -x10 -y6 || exit 1
+for name in even-horizontal even-vertical main-horizontal \
+    main-horizontal-mirrored main-vertical main-vertical-mirrored tiled; do
+	$TMUX select-layout -t layouts:many "$name" || exit 1
+done
+
+$TMUX has-session -t layouts || fail "server died during layout tests"
+exit 0

regress/list-commands.sh

@@ -0,0 +1,46 @@
+#!/bin/sh
+
+# Exercise list-commands for the full table, a single command, aliases, custom
+# and empty formats, and lookup errors.
+
+PATH=/bin:/usr/bin
+TERM=screen
+export PATH TERM
+
+[ -z "$TEST_TMUX" ] && TEST_TMUX=$(readlink -f ../tmux)
+DIR=$(mktemp -d) || exit 1
+TMUX_TMPDIR=$DIR
+export TMUX_TMPDIR
+TMUX="$TEST_TMUX -Ltest$$ -f/dev/null"
+
+cleanup()
+{
+	$TMUX kill-server 2>/dev/null
+	rm -rf "$DIR"
+}
+trap cleanup 0 1 15
+
+# Keep a server alive across commands. Otherwise a STARTSERVER-only command
+# may exit between invocations and leave a short socket-cleanup race.
+$TMUX new-session -d -s list-commands 'exec sleep 100' || exit 1
+
+all=$($TMUX list-commands) || exit 1
+printf '%s\n' "$all" | grep -q '^attach-session (attach)' || exit 1
+printf '%s\n' "$all" | grep -q '^list-commands (lscm)' || exit 1
+
+one=$($TMUX list-commands -F \
+    '#{command_list_name}|#{command_list_alias}|#{command_list_usage}' \
+    list-commands) || exit 1
+case "$one" in
+'list-commands|lscm|'*) ;;
+*) exit 1 ;;
+esac
+
+# Aliases resolve to their command, while an empty expansion prints no line.
+[ "$($TMUX list-commands -F '#{command_list_name}' lscm)" = list-commands ] ||
+	exit 1
+[ -z "$($TMUX list-commands -F '' list-commands)" ] || exit 1
+
+$TMUX list-commands tmux-no-command-$$ >/dev/null 2>&1 && exit 1
+$TMUX list-commands list >/dev/null 2>&1 && exit 1
+exit 0

regress/modal-pane.sh

@@ -105,6 +105,24 @@ drag()
 	sleep 1
 }
 
+meta_drag()
+{
+	scol="$1"
+	srow="$2"
+	ecol="$3"
+	erow="$4"
+
+	seq=$(printf '\033[<8;%s;%sM' "$scol" "$srow")
+	$TMUX2 send-keys -t "$OUTER" -l "$seq" 2>/dev/null
+	sleep 0.2
+	seq=$(printf '\033[<40;%s;%sM' "$ecol" "$erow")
+	$TMUX2 send-keys -t "$OUTER" -l "$seq" 2>/dev/null
+	sleep 0.2
+	seq=$(printf '\033[<8;%s;%sm' "$ecol" "$erow")
+	$TMUX2 send-keys -t "$OUTER" -l "$seq" 2>/dev/null
+	sleep 1
+}
+
 cleanup
 
 check_ok new-session -d -s modal -x 80 -y 24 'cat'
@@ -127,12 +145,16 @@ case "$(fmt "$modal" '#{pane_flags}')" in
 *O*) ;;
 *) fail "modal pane flags do not include O" ;;
 esac
+case "$(fmt "$modal" '#{pane_flags}')" in
+*A*) ;;
+*) fail "modal pane flags do not include A" ;;
+esac
 case "$(fmt modal:0 '#{window_flags}')" in
 *O*) ;;
 *) fail "modal window flags do not include O" ;;
 esac
 must_equal "$(fmt modal:0 '#{window_modal_pane}')" "$modal"
-must_equal "$(fmt modal:0 '#{window_zoomed_flag}')" 0
+must_equal "$(fmt modal:0 '#{window_zoomed_flag}')" 1
 
 check_fail "window already has a modal pane" \
 	new-pane -O -x 10 -y 4 'cat'
@@ -159,12 +181,14 @@ under=$($TMUX split-window -PF '#{pane_id}' -t "$p0" 'cat') ||
 sleep 1
 must_equal "$(fmt modal:0 '#{pane_id}')" "$modal"
 must_equal "$(fmt "$under" '#{pane_active}')" 0
+must_equal "$(fmt modal:0 '#{window_zoomed_flag}')" 1
 
 float=$($TMUX new-pane -PF '#{pane_id}' -x 10 -y 4 -X 5 -Y 3 'cat') ||
 	fail "new floating pane under modal failed"
 sleep 1
 must_equal "$(fmt modal:0 '#{pane_id}')" "$modal"
 must_equal "$(fmt "$float" '#{pane_active}')" 0
+must_equal "$(fmt modal:0 '#{window_zoomed_flag}')" 1
 
 check_ok new-window -d -t modal: -n other 'cat'
 check_ok select-window -t modal:other
@@ -303,6 +327,205 @@ check_ok kill-pane -t "$modal"
 sleep 1
 must_equal "$(fmt modal:0 '#{window_modal_pane}')" ''
 must_equal "$(fmt modal:0 '#{pane_id}')" "$p0"
+must_equal "$(fmt "$p0" '#{window_zoomed_flag}:#{pane_zoomed_flag}')" 0:0
+
+ignored=$($TMUX new-pane -KdPF '#{pane_id}' -t "$p0" 'cat') ||
+	fail "new-pane -K without -O failed"
+check_ok kill-pane -t "$ignored"
+
+$TMUX set -g @modal-prefix no
+$TMUX set -g @modal-root no
+$TMUX bind -n z set -g @modal-root yes
+
+modal=$($TMUX new-pane -ODKPF '#{pane_id}' -t "$p0" \
+    -x 20 -y 5 -X 20 -Y 10 'cat') ||
+	fail "new-pane -ODK failed"
+sleep 1
+$TMUX2 send-keys -t "$OUTER" C-b x z Enter
+sleep 1
+must_equal "$($TMUX show -gv @modal-prefix)" no
+must_equal "$($TMUX show -gv @modal-root)" no
+case "$($TMUX capture-pane -pt "$modal")" in
+*xz*) ;;
+*) fail "keys did not reach key-capturing modal pane" ;;
+esac
+left=$(fmt "$modal" '#{pane_left}')
+top=$(fmt "$modal" '#{pane_top}')
+meta_drag $((left + 2)) $((top + 2)) $((left + 7)) $((top + 4))
+new_left=$(fmt "$modal" '#{pane_left}')
+new_top=$(fmt "$modal" '#{pane_top}')
+[ "$new_left" -gt "$left" ] || [ "$new_top" -gt "$top" ] ||
+	fail "key-capturing modal pane did not move"
+$TMUX2 send-keys -t "$OUTER" Escape
+sleep 1
+must_equal "$(fmt modal:0 '#{window_modal_pane}')" ''
+
+modal=$($TMUX new-pane -ODKPF '#{pane_id}' -t "$p0" \
+    -x 20 -y 5 -X 20 -Y 10 'trap "" INT; exec cat') ||
+	fail "new-pane -ODK failed"
+sleep 1
+$TMUX2 send-keys -t "$OUTER" C-c
+sleep 1
+must_equal "$(fmt modal:0 '#{window_modal_pane}')" ''
+
+# A dead modal does not close on Escape or C-c without -D.
+modal=$($TMUX new-pane -OPF '#{pane_id}' -t "$p0" \
+    -x 20 -y 5 -X 20 -Y 10 'sleep 1') ||
+	fail "new-pane -O failed"
+check_ok set-option -p -t "$modal" remain-on-exit on
+sleep 2
+must_equal "$(fmt "$modal" '#{pane_dead}:#{pane_modal_flag}')" 1:1
+$TMUX2 send-keys -t "$OUTER" Escape
+sleep 1
+must_equal "$(fmt modal:0 '#{window_modal_pane}')" "$modal"
+check_ok kill-pane -t "$modal"
+sleep 1
+
+# failed-key closes successful panes and retains failed panes until a key.
+modal=$($TMUX new-pane -OPF '#{pane_id}' -t "$p0" \
+    -x 20 -y 5 -X 20 -Y 10 'sleep 1') ||
+	fail "new-pane -O failed"
+check_ok set-option -p -t "$modal" remain-on-exit failed-key
+sleep 2
+must_equal "$(fmt modal:0 '#{window_modal_pane}')" ''
+
+modal=$($TMUX new-pane -OPF '#{pane_id}' -t "$p0" \
+    -x 20 -y 5 -X 20 -Y 10 'sleep 1; exit 1') ||
+	fail "new-pane -O failed"
+check_ok set-option -p -t "$modal" remain-on-exit failed-key
+sleep 2
+must_equal "$(fmt "$modal" '#{pane_dead}:#{pane_modal_flag}')" 1:1
+must_equal "$($TMUX show-options -pv -t "$modal" remain-on-exit)" failed-key
+$TMUX2 send-keys -t "$OUTER" a
+sleep 1
+must_equal "$(fmt modal:0 '#{window_modal_pane}')" ''
+
+# A nonmodal floating pane may remain above zoom, and switching between it and
+# the zoomed tiled pane must not unzoom the window.
+check_ok new-window -d -t modal: -n float-over-zoom 'cat'
+base=$(fmt modal:float-over-zoom '#{pane_id}')
+check_ok split-window -dh -t "$base" 'cat'
+check_ok resize-pane -Z -t "$base"
+over=$($TMUX new-pane -APF '#{pane_id}' -t "$base" \
+    -x 20 -y 5 -X 20 -Y 10 'cat') ||
+	fail "new-pane -A failed"
+must_equal "$(fmt "$over" '#{pane_floating_flag}:#{pane_active}')" 1:1
+case "$(fmt "$over" '#{pane_flags}')" in
+*A*) ;;
+*) fail "float-over-zoom pane flags do not include A" ;;
+esac
+must_equal "$(fmt "$base" '#{window_zoomed_flag}:#{pane_zoomed_flag}')" 1:1
+check_ok select-pane -t "$base"
+must_equal "$(fmt "$base" '#{window_zoomed_flag}:#{pane_active}')" 1:1
+check_ok select-pane -t "$over"
+must_equal "$(fmt "$over" '#{window_zoomed_flag}:#{pane_active}')" 1:1
+client=$($TMUX list-clients -F '#{client_name}' | head -1)
+[ -n "$client" ] || fail "no client for switch-client test"
+check_ok switch-client -c "$client" -t "$base"
+must_equal "$(fmt "$base" '#{window_zoomed_flag}:#{pane_active}')" 1:1
+check_ok switch-client -c "$client" -t "$over"
+must_equal "$(fmt "$over" '#{window_zoomed_flag}:#{pane_active}')" 1:1
+check_ok kill-pane -t "$over"
+must_equal "$(fmt "$base" '#{window_zoomed_flag}:#{pane_zoomed_flag}')" 1:1
+check_ok resize-pane -Z -t "$base"
+
+ignored=$($TMUX new-pane -ALdPF '#{pane_id}' -t "$base" 'cat') ||
+	fail "new-pane -A -L failed"
+case "$(fmt "$ignored" '#{pane_flags}')" in
+*A*) fail "tiled pane flags include A" ;;
+*) ;;
+esac
+
+# Existing floating panes are filtered when zoom begins: -A panes remain in the
+# visible layout and ordinary floating panes do not.
+check_ok new-window -d -t modal: -n existing-over-zoom 'cat'
+base=$(fmt modal:existing-over-zoom '#{pane_id}')
+check_ok split-window -dh -t "$base" 'cat'
+over=$($TMUX new-pane -AdPF '#{pane_id}' -t "$base" \
+    -x 20 -y 5 -X 20 -Y 10 'cat') ||
+	fail "pre-existing new-pane -A failed"
+under=$($TMUX new-pane -dPF '#{pane_id}' -t "$base" \
+    -x 15 -y 4 -X 2 -Y 2 'cat') ||
+	fail "pre-existing ordinary new-pane failed"
+check_ok select-window -t modal:existing-over-zoom
+check_ok select-pane -t "$base"
+check_ok resize-pane -Z -t "$base"
+must_equal "$(fmt "$over" '#{pane_floating_flag}')" 1
+must_equal "$(fmt "$under" '#{pane_floating_flag}')" 0
+must_equal "$(fmt "$base" '#{window_zoomed_flag}:#{pane_zoomed_flag}')" 1:1
+
+# Geometry changed in the visible zoom layout is copied back when unzooming.
+check_ok select-pane -t "$over"
+left=$(fmt "$over" '#{pane_left}')
+top=$(fmt "$over" '#{pane_top}')
+meta_drag $((left + 2)) $((top + 2)) $((left + 7)) $((top + 4))
+new_left=$(fmt "$over" '#{pane_left}')
+new_top=$(fmt "$over" '#{pane_top}')
+[ "$new_left" -gt "$left" ] || [ "$new_top" -gt "$top" ] ||
+	fail "float-over-zoom pane did not move"
+must_equal "$(fmt "$base" '#{window_zoomed_flag}:#{pane_zoomed_flag}')" 1:1
+check_ok resize-pane -Z -t "$base"
+must_equal "$(fmt "$over" '#{pane_left}:#{pane_top}')" \
+    "$new_left:$new_top"
+must_equal "$(fmt "$under" '#{pane_floating_flag}')" 1
+
+# Resizing with the over-zoom pane active restores the original zoom target.
+check_ok resize-pane -Z -t "$base"
+check_ok select-pane -t "$over"
+check_ok resize-window -t modal:existing-over-zoom -x 90 -y 30
+must_equal "$(fmt "$base" \
+    '#{window_width}x#{window_height}:#{window_zoomed_flag}:#{pane_zoomed_flag}')" \
+    90x30:1:1
+must_equal "$(fmt "$over" '#{pane_floating_flag}:#{pane_active}')" 1:1
+
+# Natural pane exit uses a different removal path from kill-pane and must also
+# preserve zoom.
+dying=$($TMUX new-pane -AdPF '#{pane_id}' -t "$base" \
+    -x 12 -y 4 -X 4 -Y 3 'true') ||
+	fail "short-lived new-pane -A failed"
+i=0
+while $TMUX list-panes -a -F '#{pane_id}' | grep -qx "$dying"; do
+    i=$((i + 1))
+    [ $i -gt 50 ] && fail "short-lived float-over-zoom pane did not exit"
+    sleep 0.1
+done
+must_equal "$(fmt "$base" '#{window_zoomed_flag}:#{pane_zoomed_flag}')" 1:1
+
+# A pane with -A is also above a zoom target which was itself floating. The
+# temporary tiled target must sit behind retained floating panes, then return
+# to the normal floating z order when unzoomed.
+check_ok new-window -d -t modal: -n floating-zoom-target 'cat'
+base=$(fmt modal:floating-zoom-target '#{pane_id}')
+check_ok split-window -dh -t "$base" 'cat'
+target=$($TMUX new-pane -dPF '#{pane_id}' -t "$base" \
+    -x 30 -y 10 -X 10 -Y 5 'cat') ||
+	fail "floating zoom target creation failed"
+over=$($TMUX new-pane -AdPF '#{pane_id}' -t "$base" \
+    -x 15 -y 5 -X 15 -Y 8 'cat') ||
+	fail "float-over-zoom pane creation failed"
+check_ok select-window -t modal:floating-zoom-target
+check_ok select-pane -t "$target"
+must_equal "$(fmt "$target" '#{pane_z}')" 0
+must_equal "$(fmt "$over" '#{pane_z}')" 1
+
+check_ok resize-pane -Z -t "$target"
+must_equal "$(fmt "$target" \
+    '#{window_zoomed_flag}:#{pane_zoomed_flag}:#{pane_floating_flag}:#{pane_z}')" \
+    1:1:0:2
+must_equal "$(fmt "$over" '#{pane_floating_flag}:#{pane_z}')" 1:0
+check_ok select-pane -t "$over"
+must_equal "$(fmt "$over" '#{window_zoomed_flag}:#{pane_active}')" 1:1
+check_ok resize-pane -Z -t "$target"
+must_equal "$(fmt "$over" '#{pane_active}:#{pane_z}')" 1:0
+must_equal "$(fmt "$target" '#{pane_floating_flag}:#{pane_z}')" 1:1
+
+# If the target remains active, it returns to the front on unzoom.
+check_ok select-pane -t "$target"
+check_ok resize-pane -Z -t "$target"
+must_equal "$(fmt "$over" '#{pane_floating_flag}:#{pane_z}')" 1:0
+check_ok resize-pane -Z -t "$target"
+must_equal "$(fmt "$target" '#{pane_active}:#{pane_z}')" 1:0
+must_equal "$(fmt "$over" '#{pane_z}')" 1
 
 cleanup
 exit 0

regress/options-values.sh

@@ -86,6 +86,11 @@ check_value "-gv status-keys" "vi"
 check_fail "unknown value: bogus" set -g status-keys bogus
 check_value "-gv status-keys" "vi"
 
+# pane-border-lines accepts rounded as a pane border style.
+check_ok set -gw pane-border-lines rounded
+check_value "-gwv pane-border-lines" "rounded"
+check_ok set -gw pane-border-lines single
+
 # --- flag options ---------------------------------------------------------
 #
 # focus-events is an on/off flag.  Setting with no value toggles it; explicit

regress/output-commands.sh

@@ -0,0 +1,115 @@
+#!/bin/sh
+
+PATH=/bin:/usr/bin
+TERM=screen
+
+[ -z "$TEST_TMUX" ] && TEST_TMUX=$(readlink -f ../tmux)
+TMUX="$TEST_TMUX -L${TEST_SOCKET:-testO$$} -f/dev/null"
+OUT=/tmp/tmux-output-commands-$$
+EXPECTED=$(printf 'one\ntwo')
+
+cleanup()
+{
+	$TMUX kill-server 2>/dev/null
+	rm -f "$OUT"
+}
+trap cleanup EXIT HUP INT TERM
+
+$TMUX kill-server 2>/dev/null
+$TMUX new-session -d -x80 -y20 "sh -c 'printf \"\\033]133;A\\007p\\$ \\033]133;B\\007echo\\n\\033]133;C\\007one\\ntwo\\n\\033]133;D;0\\007separator\\n\\033]133;A\\007p\\$ \\033]133;B\\007broken\\n\\033]133;C\\007unfinished\"; exec sleep 100'" || exit 1
+sleep 1
+
+$TMUX copy-mode || exit 1
+$TMUX send-keys -X copy-output || exit 1
+[ "$($TMUX show-buffer)" = unfinished ] || exit 1
+
+$TMUX send-keys -X pipe-output "wc -c >$OUT" || exit 1
+sleep 1
+[ "$(cat "$OUT")" = 10 ] || exit 1
+
+$TMUX send-keys -X copy-pipe-output "wc -c >$OUT" output || exit 1
+sleep 1
+[ "$(cat "$OUT")" = 10 ] || exit 1
+[ "$($TMUX show-buffer)" = unfinished ] || exit 1
+
+$TMUX send-keys -X select-output || exit 1
+$TMUX send-keys -X copy-selection || exit 1
+[ "$($TMUX show-buffer)" = unfinished ] || exit 1
+$TMUX send-keys -X cancel || exit 1
+
+$TMUX copy-mode || exit 1
+$TMUX send-keys -X select-output || exit 1
+$TMUX send-keys -X pipe-selection "wc -c >$OUT" || exit 1
+sleep 1
+[ "$(cat "$OUT")" = 10 ] || exit 1
+$TMUX send-keys -X cancel || exit 1
+
+$TMUX copy-mode || exit 1
+$TMUX send-keys -X search-backward separator || exit 1
+$TMUX send-keys -X copy-output || exit 1
+[ "$($TMUX show-buffer)" = "$EXPECTED" ] || exit 1
+$TMUX send-keys -X cancel || exit 1
+
+$TMUX copy-mode || exit 1
+$TMUX send-keys -X search-backward one || exit 1
+$TMUX send-keys -X copy-output || exit 1
+[ "$($TMUX show-buffer)" = "$EXPECTED" ] || exit 1
+$TMUX send-keys -X cancel || exit 1
+
+$TMUX new-window -d -n plain "printf 'alpha\\nbeta\\n'; exec sleep 100" || exit 1
+sleep 1
+$TMUX copy-mode -t :plain || exit 1
+$TMUX send-keys -t :plain.0 -X copy-output -a || exit 1
+all=$($TMUX show-buffer)
+case "$all" in
+*alpha*beta*) ;;
+*) exit 1 ;;
+esac
+$TMUX send-keys -t :plain.0 -X cancel || exit 1
+
+$TMUX set-buffer -b keep unchanged || exit 1
+$TMUX copy-mode -t :plain || exit 1
+$TMUX send-keys -t :plain.0 -X copy-output || exit 1
+[ "$($TMUX show-buffer -b keep)" = unchanged ] || exit 1
+$TMUX send-keys -t :plain.0 -X cancel || exit 1
+
+$TMUX new-window -d -n empty "printf '\\033]133;A\\007p\\$ \\033]133;B\\007echo\\033]133;C\\007one\\n\\033]133;D;0\\007\\033]133;A\\007p\\$ \\033]133;B\\007true\\033]133;C\\033]133;D;0\\007'; exec sleep 100" || exit 1
+sleep 1
+$TMUX copy-mode -t :empty || exit 1
+$TMUX send-keys -t :empty.0 -X copy-output || exit 1
+[ "$($TMUX show-buffer)" = one ] || exit 1
+$TMUX send-keys -t :empty.0 -X cancel || exit 1
+
+$TMUX new-window -d -n prompt "printf '\\033]133;A\\007p\\$ \\033]133;B\\007echo\\033]133;C\\007one\\n\\033]133;D;0\\007\\033]133;A\\007p\\$ \\033]133;B\\007'; exec sleep 100" || exit 1
+sleep 1
+$TMUX copy-mode -t :prompt || exit 1
+$TMUX send-keys -t :prompt.0 -X copy-output || exit 1
+[ "$($TMUX show-buffer)" = one ] || exit 1
+$TMUX send-keys -t :prompt.0 -X cancel || exit 1
+
+$TMUX copy-mode -t :prompt || exit 1
+$TMUX send-keys -t :prompt.0 -X -N 100 cursor-down || exit 1
+$TMUX send-keys -t :prompt.0 C-o || exit 1
+[ "$($TMUX display-message -p -t :prompt.0 '#{selection_present}')" = 1 ] || exit 1
+$TMUX send-keys -t :prompt.0 -X copy-selection || exit 1
+[ "$($TMUX show-buffer)" = one ] || exit 1
+$TMUX send-keys -t :prompt.0 -X cancel || exit 1
+
+$TMUX new-window -d -n same "printf '\\033]133;A\\007p\\$ \\033]133;B\\007echo\\n\\033]133;C\\007one\\033]133;D;0\\007\\033]133;A\\007p\\$ \\033]133;B\\007'; exec sleep 100" || exit 1
+sleep 1
+$TMUX copy-mode -t :same || exit 1
+$TMUX send-keys -t :same.0 -X search-backward one || exit 1
+$TMUX send-keys -t :same.0 -X select-output || exit 1
+$TMUX send-keys -t :same.0 -X copy-selection || exit 1
+[ "$($TMUX show-buffer)" = one ] || exit 1
+$TMUX send-keys -t :same.0 -X cancel || exit 1
+
+$TMUX new-window -d -n clear "printf 'old1\\nold2\\nold3\\nold4\\nold5\\nold6\\n\\033]133;A\\007p\\$ \\033]133;B\\007echo 1; clear; ps\\n\\033]133;C\\0071\\n\\033[H\\033[2JPID TTY\\n1 pts/0\\n\\033]133;D;0\\007separator\\n\\033]133;A\\007p\\$ \\033]133;B\\007'; exec sleep 100" || exit 1
+sleep 1
+$TMUX copy-mode -t :clear || exit 1
+$TMUX send-keys -t :clear.0 C-o || exit 1
+$TMUX send-keys -t :clear.0 -X copy-selection || exit 1
+[ "$($TMUX show-buffer)" = "$(printf 'PID TTY\n1 pts/0')" ] || exit 1
+$TMUX send-keys -t :clear.0 -X cancel || exit 1
+
+exit 0

regress/pane-ops.sh

@@ -19,7 +19,10 @@
 # - respawn-pane/respawn-window refusing a live pane without -k, working on a
 #   dead pane (remain-on-exit) and killing with -k;
 # - resize-pane -x/-y in cells and percent, -L/-R/-U/-D adjustments and -Z
-#   zoom/unzoom (including implicit unzoom on split).
+#   zoom/unzoom, layout round trips, zoom target selection, pane removal,
+#   window resizing and implicit unzoom on layout changes;
+# - swap-pane preserving one or two zoomed windows, including cross-window
+#   swaps of hidden panes and zoom targets.
 #
 # window-ops.sh covers window-level commands and buffers.sh paste buffers.
 
@@ -101,6 +104,25 @@ assert_alive()
 	fi
 }
 
+# Compare layout geometry and pane ordering, ignoring the active pane and
+# last-pane history in the JSON layout. Selection is checked separately.
+pane_layout()
+{
+	$TMUX display-message -p -t "$1" '#{window_layout}' |
+		sed 's/,"a":true//g; s/,"l":[0-9][0-9]*//g'
+}
+
+check_layout()
+{
+	out=$(pane_layout "$1")
+	if [ "$out" != "$2" ]; then
+		echo "Layout for '$1' wrong."
+		echo "Expected: '$2'"
+		echo "But got:  '$out'"
+		exit 1
+	fi
+}
+
 # ---------------------------------------------------------------------------
 # split-window geometry.
 
@@ -144,7 +166,8 @@ check_panes P:0 "0:$p3 1:$p0 2:$p2 3:$p1"
 # break-pane and join-pane.
 
 # break-pane moves a pane to a new window; -P -F prints where it went and -n
-# names the new window.
+# names the new window. Moving a pane out of a zoomed window unzooms it first.
+check_ok resize-pane -Z -t "$p0"
 out=$($TMUX break-pane -d -P -F '#{window_index}:#{pane_id}' -n broken \
 	-s "$p1" -t P:)
 if [ "$out" != "1:$p1" ]; then
@@ -153,10 +176,14 @@ if [ "$out" != "1:$p1" ]; then
 fi
 check_fmt 'P:1' '#{window_name}:#{window_panes}' 'broken:1'
 check_fmt 'P:0' '#{window_panes}' '3'
+check_fmt 'P:0' '#{window_zoomed_flag}' '0'
 
-# join-pane -v moves it back (the source window, left empty, is destroyed).
+# join-pane -v moves it back (the source window, left empty, is destroyed) and
+# also unzooms the destination before changing its layout.
+check_ok resize-pane -Z -t "$p0"
 check_ok join-pane -d -v -s P:broken.0 -t "$p2"
 check_fmt 'P:0' '#{window_panes}' '4'
+check_fmt 'P:0' '#{window_zoomed_flag}' '0'
 if $TMUX has-session -t P:broken 2>/dev/null; then
 	echo "Window 'broken' still exists after join-pane."
 	exit 1
@@ -299,6 +326,122 @@ check_fmt 'P:0' '#{window_panes}' '5'
 p6=$($TMUX display-message -p -t P:0.2 '#{pane_id}')
 check_ok kill-pane -t "$p6"
 
+# Zoom and unzoom preserve the exact tiled layout. Selecting another pane
+# without -Z unzooms, while -Z transfers zoom to the selected pane.
+layout=$(pane_layout P:0)
+check_ok select-pane -t "$p0"
+check_ok resize-pane -Z -t "$p0"
+check_ok select-pane -t "$p2"
+check_fmt "$p2" '#{window_zoomed_flag}:#{pane_active}' '0:1'
+check_layout P:0 "$layout"
+
+check_ok select-pane -t "$p0"
+check_ok resize-pane -Z -t "$p0"
+check_ok select-pane -Z -t "$p2"
+check_fmt "$p2" '#{window_zoomed_flag}:#{pane_zoomed_flag}:#{pane_active}' \
+	'1:1:1'
+check_ok resize-pane -Z -t "$p2"
+check_layout P:0 "$layout"
+
+# Directional selection temporarily restores the full layout to find its
+# neighbour, then follows the same unzoom or -Z transfer rules.
+check_ok select-pane -t "$p0"
+check_ok resize-pane -Z -t "$p0"
+check_ok select-pane -t "$p0"
+check_fmt "$p0" '#{window_zoomed_flag}:#{pane_zoomed_flag}:#{pane_active}' \
+	'1:1:1'
+check_ok select-pane -D -t "$p0"
+check_fmt "$p2" '#{window_zoomed_flag}:#{pane_active}' '0:1'
+
+check_ok select-pane -t "$p0"
+check_ok resize-pane -Z -t "$p0"
+check_ok select-pane -D -Z -t "$p0"
+check_fmt "$p2" '#{window_zoomed_flag}:#{pane_zoomed_flag}:#{pane_active}' \
+	'1:1:1'
+check_ok resize-pane -Z -t "$p2"
+check_layout P:0 "$layout"
+
+# The last-pane path has separate zoom handling, both with and without -Z.
+check_ok select-pane -t "$p0"
+check_ok select-pane -t "$p2"
+check_ok resize-pane -Z -t "$p2"
+check_ok select-pane -l -t P:0
+check_fmt "$p0" '#{window_zoomed_flag}:#{pane_zoomed_flag}:#{pane_active}' \
+	'0:0:1'
+
+check_ok select-pane -t "$p0"
+check_ok select-pane -t "$p2"
+check_ok resize-pane -Z -t "$p2"
+check_ok select-pane -l -Z -t P:0
+check_fmt "$p0" '#{window_zoomed_flag}:#{pane_zoomed_flag}:#{pane_active}' \
+	'1:1:1'
+check_ok resize-pane -Z -t "$p0"
+check_layout P:0 "$layout"
+
+# Killing either a hidden ordinary pane or the zoom target unzooms.
+check_ok new-window -d -t P:12 -n zoom-kill 'cat'
+zk0=$($TMUX display-message -p -t P:12.0 '#{pane_id}')
+zk1=$($TMUX split-window -d -P -F '#{pane_id}' -t P:12.0 'cat')
+zk2=$($TMUX split-window -d -P -F '#{pane_id}' -t P:12.0 'cat')
+check_ok resize-pane -Z -t "$zk0"
+check_ok kill-pane -t "$zk1"
+check_fmt "$zk0" '#{window_panes}:#{window_zoomed_flag}:#{pane_zoomed_flag}' \
+	'2:0:0'
+check_ok resize-pane -Z -t "$zk0"
+check_ok kill-pane -t "$zk0"
+check_fmt "$zk2" '#{window_panes}:#{window_zoomed_flag}:#{pane_zoomed_flag}' \
+	'1:0:0'
+check_ok kill-window -t P:12
+
+# The same cases through natural process exit exercise server_destroy_pane.
+check_ok new-window -d -t P:13 -n zoom-exit 'cat'
+ze0=$($TMUX display-message -p -t P:13.0 '#{pane_id}')
+ze1=$($TMUX split-window -d -P -F '#{pane_id}' -t P:13.0 'cat')
+ze2=$($TMUX split-window -d -P -F '#{pane_id}' -t P:13.0 'cat')
+check_ok resize-pane -Z -t "$ze0"
+check_ok send-keys -t "$ze1" C-d
+i=0
+while [ "$($TMUX display-message -p -t P:13 '#{window_panes}')" != 2 ]; do
+	i=$((i + 1))
+	[ $i -gt 50 ] && { echo "Hidden pane did not exit."; exit 1; }
+	sleep 0.1
+done
+check_fmt "$ze0" '#{window_zoomed_flag}:#{pane_zoomed_flag}' '0:0'
+check_ok resize-pane -Z -t "$ze2"
+check_ok send-keys -t "$ze2" C-d
+i=0
+while [ "$($TMUX display-message -p -t P:13 '#{window_panes}')" != 1 ]; do
+	i=$((i + 1))
+	[ $i -gt 50 ] && { echo "Zoomed pane did not exit."; exit 1; }
+	sleep 0.1
+done
+check_fmt "$ze0" '#{window_zoomed_flag}:#{pane_zoomed_flag}' '0:0'
+check_ok kill-window -t P:13
+
+# resize-window restores both tiled and floating zoom targets after rebuilding
+# the layout at the new size.
+check_ok new-window -d -t P:14 -n zoom-resize 'cat'
+zr0=$($TMUX display-message -p -t P:14.0 '#{pane_id}')
+check_ok split-window -d -t P:14.0 'cat'
+check_ok resize-pane -Z -t "$zr0"
+check_ok resize-window -t P:14 -x 90 -y 30
+check_fmt "$zr0" \
+	'#{window_width}x#{window_height}:#{window_zoomed_flag}:#{pane_zoomed_flag}' \
+	'90x30:1:1'
+check_ok resize-pane -Z -t "$zr0"
+zrf=$($TMUX new-pane -dP -F '#{pane_id}' -t P:14 -x 20 -y 6 'cat')
+zrf_size=$($TMUX display-message -p -t "$zrf" \
+	'#{pane_width}x#{pane_height}')
+check_ok resize-pane -Z -t "$zrf"
+check_ok resize-window -t P:14 -x 100 -y 32
+check_fmt "$zrf" \
+	'#{window_width}x#{window_height}:#{window_zoomed_flag}:#{pane_zoomed_flag}' \
+	'100x32:1:1'
+check_ok resize-pane -Z -t "$zrf"
+check_fmt "$zrf" '#{pane_floating_flag}:#{pane_width}x#{pane_height}' \
+	"1:$zrf_size"
+check_ok kill-window -t P:14
+
 # ---------------------------------------------------------------------------
 # kill-pane.
 
@@ -307,8 +450,10 @@ check_ok kill-pane -t "$p3"
 check_panes P:0 "0:$p0 1:$p2 2:$p1"
 
 # -a kills every pane except the target.
+check_ok resize-pane -Z -t "$p0"
 check_ok kill-pane -a -t "$p0"
 check_panes P:0 "0:$p0"
+check_fmt "$p0" '#{window_zoomed_flag}:#{pane_zoomed_flag}' '0:0'
 
 # Killing the last pane in a window kills the window.
 check_ok new-window -d -t P:7 -n goner
@@ -516,6 +661,10 @@ check_panes P:3 "0:$r0 1:$r1 2:$r2"
 # Swapping a pane with itself quietly does nothing.
 check_ok swap-pane -d -s "$r1" -t "$r1"
 check_panes P:3 "0:$r0 1:$r1 2:$r2"
+check_ok resize-pane -Z -t "$r1"
+check_ok swap-pane -d -Z -s "$r1" -t "$r1"
+check_fmt "$r1" '#{window_zoomed_flag}:#{pane_zoomed_flag}' '1:1'
+check_ok resize-pane -Z -t "$r1"
 
 # Panes can be swapped between different windows.
 check_ok swap-pane -d -s "$o0" -t "$r1"
@@ -525,10 +674,38 @@ check_ok swap-pane -d -s "$r1" -t "$o0"
 check_panes P:3 "0:$r0 1:$r1 2:$r2"
 check_panes P:5 "0:$o0"
 
+# With both windows zoomed, -Z preserves each window's zoom when hidden panes
+# are exchanged and when the zoom targets themselves are exchanged.
+o1=$($TMUX split-window -dP -F '#{pane_id}' -t P:5.0)
+check_ok resize-pane -Z -t "$r0"
+check_ok resize-pane -Z -t "$o0"
+check_ok swap-pane -d -Z -s "$r1" -t "$o1"
+check_fmt "$r0" \
+	'#{window_name}:#{window_zoomed_flag}:#{pane_zoomed_flag}' 'swaps:1:1'
+check_fmt "$o0" \
+	'#{window_name}:#{window_zoomed_flag}:#{pane_zoomed_flag}' 'other:1:1'
+check_fmt "$r1" '#{window_name}' 'other'
+check_fmt "$o1" '#{window_name}' 'swaps'
+
+check_ok swap-pane -d -Z -s "$r0" -t "$o0"
+check_fmt "$o0" \
+	'#{window_name}:#{window_zoomed_flag}:#{pane_zoomed_flag}' 'swaps:1:1'
+check_fmt "$r0" \
+	'#{window_name}:#{window_zoomed_flag}:#{pane_zoomed_flag}' 'other:1:1'
+check_ok resize-pane -Z -t "$o0"
+check_ok resize-pane -Z -t "$r0"
+
+# Restore the original panes before the remaining swap tests.
+check_ok swap-pane -d -s "$r0" -t "$o0"
+check_ok swap-pane -d -s "$r1" -t "$o1"
+check_ok kill-pane -t "$o1"
+check_panes P:3 "0:$r0 1:$r1 2:$r2"
+check_panes P:5 "0:$o0"
+
 # -Z keeps the window zoomed across the swap.
 check_ok resize-pane -Z -t "$r0"
 check_ok swap-pane -d -Z -s "$r0" -t "$r1"
-check_fmt 'P:3' '#{window_zoomed_flag}' '1'
+check_fmt "$r0" '#{window_zoomed_flag}:#{pane_zoomed_flag}' '1:1'
 check_ok resize-pane -Z -t P:3
 check_panes P:3 "0:$r1 1:$r0 2:$r2"
 

regress/prompt-keys.sh

@@ -217,7 +217,36 @@ $OUT send-keys M-r || exit 1
 settle
 status_line | grep -q '>' || fail "status-line prompt not drawn on the status line"
 
-# --- 11. emacs cursor-marker edit, accept recovers the exact buffer. ---
+# --- 11. Invalid UTF-8 input must not desynchronize the prompt buffer. ---
+$OUT send-keys -H e6 85 5f || exit 1	# invalid UTF-8, then "_"
+settle
+$IN display-message -p '#{version}' >/dev/null 2>&1 || \
+	fail "invalid UTF-8 append killed inner tmux"
+status_line | grep -qF "> _" || \
+	fail "invalid UTF-8 append did not keep prompt usable (got '$(status_line)')"
+$OUT send-keys Enter || exit 1
+settle
+[ "$($IN show -gv @r)" = "_" ] || \
+	fail "invalid UTF-8 append recovered '$($IN show -gv @r)', wanted '_'"
+
+$IN set -g @r "SENTINEL" || exit 1
+$OUT send-keys M-r || exit 1
+settle
+$OUT send-keys -H e6 85 04 || exit 1	# invalid UTF-8, then C-d
+settle
+$IN display-message -p '#{version}' >/dev/null 2>&1 || \
+	fail "invalid UTF-8 delete killed inner tmux"
+status_line | grep -q '>' || \
+	fail "invalid UTF-8 delete closed the prompt (got '$(status_line)')"
+$OUT send-keys Escape || exit 1
+settle
+[ "$($IN show -gv @r)" = "SENTINEL" ] || \
+	fail "invalid UTF-8 delete accepted the prompt"
+
+# --- 12. emacs cursor-marker edit, accept recovers the exact buffer. ---
+$IN set -g @r "" || exit 1
+$OUT send-keys M-r || exit 1
+settle
 $OUT send-keys -l "abc" || exit 1
 $OUT send-keys Home || exit 1
 $OUT send-keys -l "X" || exit 1
@@ -229,7 +258,7 @@ settle
 [ "$($IN show -gv @r)" = "Xabc" ] || \
 	fail "status-line accept recovered '$($IN show -gv @r)', wanted 'Xabc'"
 
-# --- 12. Unicode on the status line: insert, move, delete wide char. ---
+# --- 13. Unicode on the status line: insert, move, delete wide char. ---
 $IN set -g @r "" || exit 1
 $OUT send-keys M-r || exit 1
 settle
@@ -249,7 +278,7 @@ settle
 [ "$($IN show -gv @r)" = "Za" ] || \
 	fail "status-line wide edit recovered '$($IN show -gv @r)', wanted 'Za'"
 
-# --- 13. Overflow: more text than fits stays within the line and is kept. ---
+# --- 14. Overflow: more text than fits stays within the line and is kept. ---
 big="0123456789012345678901234567890123456789012345678901234567890123456789ABCDEFGHIJ"
 $IN set -g @r "" || exit 1
 $OUT send-keys M-r || exit 1
@@ -264,7 +293,7 @@ settle
 # The whole buffer was kept despite only part being visible.
 [ "$($IN show -gv @r)" = "$big" ] || fail "overflowing prompt lost buffer content"
 
-# --- 14. Escape closes the status-line prompt cleanly. ---
+# --- 15. Escape closes the status-line prompt cleanly. ---
 $IN set -g @r "SENTINEL" || exit 1
 $OUT send-keys M-r || exit 1
 settle

regress/prompt-words-history.sh

@@ -0,0 +1,165 @@
+#!/bin/sh
+
+# Cover prompt word movement in emacs and vi modes, ambiguous inline command
+# completion, and the show/clear-prompt-history command surface.
+
+PATH=/bin:/usr/bin
+TERM=screen
+LC_ALL=C.UTF-8
+export PATH TERM LC_ALL
+
+[ -z "$TEST_TMUX" ] && TEST_TMUX=$(readlink -f ../tmux)
+DIR=$(mktemp -d) || exit 1
+TMUX_TMPDIR=$DIR
+export TMUX_TMPDIR
+INNER="$TEST_TMUX -LtestI$$ -f/dev/null"
+OUTER="$TEST_TMUX -LtestO$$ -f/dev/null"
+
+fail()
+{
+	echo "$*" >&2
+	exit 1
+}
+
+cleanup()
+{
+	$OUTER kill-server 2>/dev/null
+	$INNER kill-server 2>/dev/null
+	rm -rf "$DIR"
+}
+trap cleanup 0 1 15
+
+capture()
+{
+	$OUTER capture-pane -p -t outer:0.0 2>/dev/null
+}
+
+wait_result()
+{
+	want=$1
+	i=0
+	while [ "$i" -lt 50 ]; do
+		got=$($INNER show-option -gqv @result 2>/dev/null)
+		[ "$got" = "$want" ] && return 0
+		sleep 0.1
+		i=$((i + 1))
+	done
+	fail "prompt result is '$got', expected '$want'"
+}
+
+bind_prompt()
+{
+	initial=$1
+	$INNER bind-key -n M-r command-prompt -I "$initial" -p '(word)' \
+		"set-option -g @result '%%'" || exit 1
+}
+
+run_prompt()
+{
+	want=$1
+	shift
+	$INNER set-option -g @result sentinel || exit 1
+	$OUTER send-keys M-r || exit 1
+	sleep 0.2
+	$OUTER send-keys "$@" || exit 1
+	$OUTER send-keys Enter || exit 1
+	wait_result "$want"
+}
+
+run_vi_prompt()
+{
+	want=$1
+	shift
+	$INNER set-option -g @result sentinel || exit 1
+	$OUTER send-keys M-r || exit 1
+	sleep 0.2
+	# Send Escape separately so the terminal's escape-time handling does not
+	# combine it with the first vi command as a Meta key.
+	$OUTER send-keys Escape || exit 1
+	# The inner client must see Escape as a complete key, not the prefix of a
+	# Meta sequence (the default escape-time is 500 milliseconds).
+	sleep 0.7
+	$OUTER send-keys "$@" || exit 1
+	$OUTER send-keys Enter || exit 1
+	wait_result "$want"
+}
+
+$INNER new-session -d -s prompt -x80 -y24 'exec sleep 100' || exit 1
+$INNER set-option -g status on || exit 1
+$INNER set-option -g status-position bottom || exit 1
+$INNER set-option -g window-size manual || exit 1
+$OUTER new-session -d -s outer -x80 -y24 "$INNER attach -t prompt" || exit 1
+$OUTER set-option -g status off || exit 1
+$OUTER set-option -g window-size manual || exit 1
+sleep 1
+
+# Emacs Meta-f stops after the first word; Meta-b returns to the start of the
+# previous word. Inserting a marker makes the cursor position observable.
+$INNER set-option -g status-keys emacs || exit 1
+bind_prompt 'one two'
+run_prompt 'oneX two' Home M-f X
+bind_prompt 'one two'
+run_prompt 'one Xtwo' M-b X
+
+# Vi translation and the distinct separator-aware and WORD motions.
+$INNER set-option -g status-keys vi || exit 1
+bind_prompt 'one-two three'
+run_vi_prompt 'one-two Xthree' b i X
+bind_prompt 'one-two three'
+run_vi_prompt 'one-two Xthree' B i X
+bind_prompt 'one-two three'
+run_vi_prompt 'oneX-two three' 0 w i X
+bind_prompt 'one-two three'
+run_vi_prompt 'one-two Xthree' 0 W i X
+bind_prompt 'one-two three'
+run_vi_prompt 'oneX-two three' 0 e a X
+bind_prompt 'one-two three'
+run_vi_prompt 'one-twoX three' 0 E a X
+
+# "show-" has several command matches and no longer common prefix. Tab keeps
+# the input and draws the sorted candidates inline.
+$INNER set-option -g status-keys emacs || exit 1
+bind_prompt ''
+$OUTER send-keys M-r || exit 1
+sleep 0.2
+$OUTER send-keys -l 'show-' || exit 1
+$OUTER send-keys Tab || exit 1
+sleep 0.2
+captured=$(capture)
+printf '%s\n' "$captured" | grep -Fq 'show-buffer' ||
+	fail "ambiguous completion list was not drawn"
+printf '%s\n' "$captured" | grep -Fq 'show-environment' ||
+	fail "ambiguous completion list was incomplete"
+$OUTER send-keys Escape || exit 1
+
+# Add entries to both history rings through real prompts.
+bind_prompt 'history-command'
+run_prompt 'history-command'
+$INNER bind-key -n M-s command-prompt -T search -I history-search \
+	-p '(search-history)' "set-option -g @result '%%'" || exit 1
+$OUTER send-keys M-s || exit 1
+$OUTER send-keys Enter || exit 1
+wait_result history-search
+
+command_history=$($INNER show-prompt-history -T command) || exit 1
+printf '%s\n' "$command_history" | grep -Fq 'history-command' ||
+	fail "command history entry missing"
+search_history=$($INNER show-prompt-history -T search) || exit 1
+printf '%s\n' "$search_history" | grep -Fq 'history-search' ||
+	fail "search history entry missing"
+all_history=$($INNER show-prompt-history) || exit 1
+printf '%s\n' "$all_history" | grep -Fq 'History for command:' || exit 1
+printf '%s\n' "$all_history" | grep -Fq 'History for search:' || exit 1
+
+$INNER show-prompt-history -T invalid >/dev/null 2>&1 &&
+	fail "invalid show history type succeeded"
+$INNER clear-prompt-history -T invalid >/dev/null 2>&1 &&
+	fail "invalid clear history type succeeded"
+$INNER clear-prompt-history -T command || exit 1
+$INNER show-prompt-history -T command | grep -Fq history-command &&
+	fail "type-specific history clear failed"
+$INNER clear-prompt-history || exit 1
+$INNER show-prompt-history | grep -Fq history-search &&
+	fail "all-history clear failed"
+
+exit 0

regress/respawn-pane-control-lag.sh

@@ -0,0 +1,87 @@
+#!/bin/sh
+
+# respawn-pane frees the pane's buffer and creates an empty one. The pane
+# offsets and each control client's offsets used to keep pointing into the old
+# buffer, so if an attached control client had not caught up on the pane's
+# output, the next read from the new process ran off the end of the new buffer
+# and the server crashed in input_parse.
+#
+# Two ways for a client to be behind are tested: a control client whose output
+# goes down a fifo that is never read (a second, healthy control client keeps
+# the pane being read), and a healthy control client viewing a session that
+# the pane's window has been moved out of.
+
+PATH=/bin:/usr/bin
+TERM=screen
+
+[ -z "$TEST_TMUX" ] && TEST_TMUX=$(readlink -f ../tmux)
+TMUX="$TEST_TMUX -Ltest"
+$TMUX kill-server 2>/dev/null
+
+DIR=$(mktemp -d)
+FIFO=$DIR/fifo
+SERVER=
+
+mkfifo "$FIFO" || exit 1
+
+cleanup() {
+	[ -n "$SERVER" ] && kill -9 "$SERVER" 2>/dev/null
+	$TMUX kill-server 2>/dev/null
+	exec 8<&- 2>/dev/null
+	rm -rf "$DIR"
+}
+trap cleanup 0 1 15
+
+alive() {
+	if ! kill -0 "$SERVER" 2>/dev/null; then
+		SERVER=
+		echo "server died after $1"
+		exit 1
+	fi
+	$TMUX has -t rt || exit 1
+}
+
+wait_clients() {
+	n=0
+	while [ $n -lt 50 ]; do
+		[ "$($TMUX lsc 2>/dev/null | wc -l)" -ge $1 ] && return
+		sleep 0.1
+		n=$((n + 1))
+	done
+	echo "control clients did not attach"; exit 1
+}
+
+# A detached session with a pane that writes a line every 10 milliseconds.
+$TMUX -f/dev/null new -d -x 80 -y 24 -s rt \
+	'while :; do echo xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx; sleep 0.01; done' ||
+	exit 1
+SERVER=$($TMUX display -pt rt '#{pid}')
+
+# One control client with output down the unread fifo and one reading
+# normally; stdin of both held open by sleep so they stay attached.
+( sleep 60 ) | $TMUX -f/dev/null -C attach -t rt >"$FIFO" 2>&1 &
+exec 8<"$FIFO"
+( sleep 60 ) | $TMUX -f/dev/null -C attach -t rt >/dev/null 2>&1 &
+wait_clients 2
+
+# Let the first client fall behind, then respawn the pane. The new process
+# writes at once and the server must survive reading it.
+sleep 3
+$TMUX respawn-pane -k -t rt:0 'echo respawned; sleep 60' || exit 1
+sleep 1
+alive "respawn-pane with a lagging control client"
+
+# Now a pane whose window is moved out of the session both clients view: their
+# offsets for it stop advancing, so they fall behind until it is respawned.
+$TMUX neww -d -t rt \
+	'while :; do echo yyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy; sleep 0.01; done' ||
+	exit 1
+sleep 1
+$TMUX new -d -s other || exit 1
+$TMUX movew -d -s rt:1 -t other: || exit 1
+sleep 2
+$TMUX respawn-pane -k -t other:1 'echo respawned; sleep 60' || exit 1
+sleep 1
+alive "respawn-pane on a window moved out of the clients' session"
+
+exit 0

regress/screen-redraw-floating.sh

@@ -107,6 +107,12 @@ $TMUX2 new-pane -x28 -y8 -X4 -Y1 -B double \
 	"sh -c 'printf FLOAT; exec sleep 100'" || exit 1
 compare floating-border-double
 
+# Larger floating pane with rounded border lines.
+new_scene 40 12
+$TMUX2 new-pane -x28 -y8 -X4 -Y1 -B rounded \
+	"sh -c 'printf FLOAT; exec sleep 100'" || exit 1
+compare floating-border-rounded
+
 # Floating pane with no border lines: redraw_mark_pane_borders returns early so
 # the float has no border at all, only its (clipped) content over the base pane.
 new_scene 40 12

regress/screen-redraw-outside.sh

@@ -93,6 +93,15 @@ $TMUX2 splitw -v "$C" || exit 1
 $TMUX2 select-layout tiled || exit 1
 compare outside-both-2x2
 
+# Top pane status supplies internal horizontal borders, but there is no pane
+# below the window to supply its bottom edge.
+new_scene 28 9
+$TMUX2 setw pane-border-status top || exit 1
+$TMUX2 setw pane-border-format "" || exit 1
+compare outside-both-status-top-single
+$TMUX2 splitw -v "$C" || exit 1
+compare outside-both-status-top-split
+
 # Window BIGGER than the client: only part of the window is viewed and the view
 # can be panned (refresh-client). This exercises a non-zero scene offset.
 # A 2x2 grid in a 60x20 window viewed through the 40x14 client.

regress/screen-redraw-results/floating-border-rounded.result

@@ -0,0 +1,12 @@
+base
+    ╭──────────────────────────╮
+    │FLOAT                     │
+    │                          │
+    │                          │
+    │                          │
+    │                          │
+    │                          │
+    ╰──────────────────────────╯
+
+
+

regress/screen-redraw-results/outside-both-status-top-single.result

@@ -0,0 +1,14 @@
+────────────────────────────┐···········
+OUT01 abcdefghij            │···········
+OUT02 abcdefghij            │···········
+OUT03 abcdefghij            │···········
+OUT04 abcdefghij            │···········
+OUT05 abcdefghij            │···········
+OUT06 abcdefghij            │···········
+OUT07 abcdefghij            │···········
+                            │···········
+────────────────────────────┘···········
+········································
+········································
+········································
+········································

regress/screen-redraw-results/outside-both-status-top-split.result

@@ -0,0 +1,14 @@
+────────────────────────────┐···········
+OUT06 abcdefghij            │···········
+OUT07 abcdefghij            │···········
+                            │···········
+────────────────────────────┤···········
+PAN05 abcdefghij            │···········
+PAN06 abcdefghij            │···········
+PAN07 abcdefghij            │···········
+                            │···········
+────────────────────────────┘···········
+········································
+········································
+········································
+········································

regress/screen-redraw-scrollbars-auto-hide.sh

@@ -0,0 +1,96 @@
+#!/bin/sh
+
+# Auto-hide scrollbars appear on activity or pointer hover, then disappear
+# after pane-scrollbars-timeout. Compare captures of the same copy-mode view so
+# only the overlay scrollbar changes.
+
+PATH=/bin:/usr/bin
+TERM=screen
+LC_ALL=C.UTF-8
+export PATH TERM LC_ALL
+
+[ -z "$TEST_TMUX" ] && TEST_TMUX=$(readlink -f ../tmux)
+OUTER="$TEST_TMUX -LtestA$$ -f/dev/null"
+INNER="$TEST_TMUX -LtestB$$ -f/dev/null"
+DIR=$(mktemp -d) || exit 1
+HIDDEN=$DIR/hidden
+VISIBLE=$DIR/visible
+AFTER=$DIR/after
+
+fail()
+{
+	echo "$*" >&2
+	exit 1
+}
+
+cleanup()
+{
+	$OUTER kill-server 2>/dev/null
+	$INNER kill-server 2>/dev/null
+	rm -rf "$DIR"
+}
+trap cleanup 0 1 15
+
+capture()
+{
+	$OUTER capture-pane -pe -t outer:0.0 >"$1" || exit 1
+}
+
+wait_for_client()
+{
+	i=0
+	while [ "$i" -lt 50 ]; do
+		$INNER list-clients 2>/dev/null | grep -q . && return 0
+		sleep 0.1
+		i=$((i + 1))
+	done
+	fail "inner client did not attach"
+}
+
+$INNER new-session -d -s inner -x40 -y12 \
+	"sh -c 'seq 50; exec sleep 100'" || exit 1
+$INNER set-option -g status off || exit 1
+$INNER set-option -g window-size manual || exit 1
+$INNER set-option -g mouse on || exit 1
+$INNER set-window-option pane-scrollbars auto-hide || exit 1
+$INNER set-window-option pane-scrollbars-timeout 3000 || exit 1
+$INNER set-window-option pane-scrollbars-style \
+	'bg=colour196,fg=colour231,width=1,pad=0' || exit 1
+
+$OUTER new-session -d -s outer -x40 -y12 "$INNER attach -t inner" || exit 1
+$OUTER set-option -g status off || exit 1
+$OUTER set-option -g window-size manual || exit 1
+wait_for_client
+
+# Enter copy mode and choose a stable view. The initial show timer is allowed
+# to expire before taking the hidden reference capture.
+$INNER copy-mode -H || exit 1
+$INNER send-keys -X history-top || exit 1
+sleep 3.5
+capture "$HIDDEN"
+
+# A copy-mode page movement shows the overlay and starts its timer. Capture
+# that view immediately, then again after the timeout without moving it.
+$INNER send-keys -X page-down || exit 1
+sleep 0.1
+capture "$VISIBLE"
+sleep 3.5
+capture "$AFTER"
+cmp -s "$VISIBLE" "$AFTER" && fail "scrollbar did not hide after timeout"
+
+# Use the post-movement hidden scene as the reference for pointer hover. SGR
+# mouse column 40 is the right-hand scrollbar; moving to column 5 restarts the
+# timer without changing the copy-mode view.
+cp "$AFTER" "$HIDDEN"
+hover=$(printf '\033[<35;40;5M')
+$OUTER send-keys -l "$hover" || exit 1
+sleep 0.1
+capture "$VISIBLE"
+cmp -s "$HIDDEN" "$VISIBLE" && fail "scrollbar did not appear on hover"
+away=$(printf '\033[<35;5;5M')
+$OUTER send-keys -l "$away" || exit 1
+sleep 3.5
+capture "$AFTER"
+cmp -s "$HIDDEN" "$AFTER" || fail "scrollbar did not hide after hover"
+
+exit 0

regress/server-access.sh

@@ -0,0 +1,112 @@
+#!/bin/sh
+
+# Exercise the unprivileged server-access surface: user and group ACL entries,
+# read-only/writable transitions, listing, removal, implied addition, and
+# command errors. Actual connections from another UID require privileges and
+# deliberately do not form part of this test.
+
+PATH=/bin:/usr/bin
+TERM=screen
+export PATH TERM
+
+[ -z "$TEST_TMUX" ] && TEST_TMUX=$(readlink -f ../tmux)
+TMUX="$TEST_TMUX -LtestA$$ -f/dev/null"
+OUT=$(mktemp) || exit 1
+
+fail()
+{
+	echo "$*" >&2
+	exit 1
+}
+
+cleanup()
+{
+	$TMUX kill-server 2>/dev/null
+	rm -f "$OUT"
+}
+trap cleanup 0 1 15
+
+expect_fail()
+{
+	message=$1
+	shift
+	if $TMUX "$@" >"$OUT" 2>&1; then
+		fail "$message: command unexpectedly succeeded"
+	fi
+}
+
+assert_entry()
+{
+	entry=$1
+	$TMUX server-access -l >"$OUT" || exit 1
+	grep -Fxq "$entry" "$OUT" ||
+		fail "missing ACL entry '$entry'"
+}
+
+assert_no_entry()
+{
+	entry=$1
+	$TMUX server-access -l >"$OUT" || exit 1
+	if grep -Fxq "$entry" "$OUT"; then
+		fail "unexpected ACL entry '$entry'"
+	fi
+}
+
+owner_uid=$(id -u)
+owner_name=$(id -un)
+
+# nobody is the non-owner test identity. Derive its primary group rather than
+# assuming whether the system calls it nobody, nogroup, or something else.
+acl_user=nobody
+acl_group=$(id -gn "$acl_user" 2>/dev/null) ||
+	fail "the nobody account is unavailable"
+[ "$owner_name" != "$acl_user" ] || fail "test cannot run as nobody"
+
+$TMUX new-session -d -s access 'exec sleep 100' || exit 1
+
+# The owner is installed as writable at server startup (root is intentionally
+# omitted from display output).
+if [ "$owner_uid" != 0 ]; then
+	assert_entry "$owner_name (U,W)"
+fi
+
+# User ACL lifecycle, including duplicate and missing-entry errors.
+$TMUX server-access -a "$acl_user" || exit 1
+assert_entry "$acl_user (U,W)"
+expect_fail "duplicate user addition" server-access -a "$acl_user"
+$TMUX server-access -r "$acl_user" || exit 1
+assert_entry "$acl_user (U,R)"
+$TMUX server-access -w "$acl_user" || exit 1
+assert_entry "$acl_user (U,W)"
+$TMUX server-access -d "$acl_user" || exit 1
+assert_no_entry "$acl_user (U,W)"
+expect_fail "removing absent user" server-access -d "$acl_user"
+
+# -r and -w imply -a when an entry is absent.
+$TMUX server-access -r "$acl_user" || exit 1
+assert_entry "$acl_user (U,R)"
+$TMUX server-access -d "$acl_user" || exit 1
+
+# The same lifecycle for a group exercises the separate ACL key space.
+$TMUX server-access -g -a -r "$acl_group" || exit 1
+assert_entry "$acl_group (G,R)"
+$TMUX server-access -g -w "$acl_group" || exit 1
+assert_entry "$acl_group (G,W)"
+expect_fail "duplicate group addition" server-access -g -a "$acl_group"
+$TMUX server-access -g -d "$acl_group" || exit 1
+assert_no_entry "$acl_group (G,W)"
+expect_fail "removing absent group" server-access -g -d "$acl_group"
+
+# Parser and lookup errors, plus the immutable owner/root entries.
+expect_fail "missing ACL subject" server-access -a
+expect_fail "unknown user" server-access -a "tmux-no-user-$$"
+expect_fail "unknown group" server-access -g -a "tmux-no-group-$$"
+expect_fail "conflicting add/delete" server-access -a -d "$acl_user"
+expect_fail "conflicting read/write" server-access -r -w "$acl_user"
+expect_fail "changing server owner" server-access -r "$owner_name"
+if [ "$owner_name" != root ]; then
+	expect_fail "changing root access" server-access -a root
+fi
+
+$TMUX has-session -t access || fail "server exited during ACL updates"
+exit 0

regress/switch-mode.sh

@@ -0,0 +1,203 @@
+#!/bin/sh
+
+# Exercise switch-mode's session and window lists with a real attached client:
+# fuzzy filtering, movement and selection, the default and custom commands,
+# no-match cancellation, resize, zoom restoration, and -k mode teardown.
+
+PATH=/bin:/usr/bin
+TERM=screen
+LC_ALL=C.UTF-8
+export PATH TERM LC_ALL
+
+[ -z "$TEST_TMUX" ] && TEST_TMUX=$(readlink -f ../tmux)
+DIR=$(mktemp -d) || exit 1
+TMUX_TMPDIR=$DIR
+export TMUX_TMPDIR
+INNER="$TEST_TMUX -LtestI$$ -f/dev/null"
+OUTER="$TEST_TMUX -LtestO$$ -f/dev/null"
+
+fail()
+{
+	echo "$*" >&2
+	exit 1
+}
+
+cleanup()
+{
+	$OUTER kill-server 2>/dev/null
+	$INNER kill-server 2>/dev/null
+	rm -rf "$DIR"
+}
+trap cleanup 0 1 15
+
+capture()
+{
+	$OUTER capture-pane -p -t outer:0.0 2>/dev/null
+}
+
+wait_capture()
+{
+	marker=$1
+	i=0
+	while [ "$i" -lt 50 ]; do
+		captured=$(capture)
+		printf '%s\n' "$captured" | grep -Fq "$marker" && return 0
+		sleep 0.1
+		i=$((i + 1))
+	done
+	fail "timed out waiting for '$marker'"
+}
+
+wait_count()
+{
+	marker=$1
+	want=$2
+	i=0
+	while [ "$i" -lt 50 ]; do
+		captured=$(capture)
+		count=$(printf '%s\n' "$captured" | grep -Fc "$marker")
+		[ "$count" -eq "$want" ] && return 0
+		sleep 0.1
+		i=$((i + 1))
+	done
+	fail "found $count '$marker' rows, expected $want"
+}
+
+wait_format()
+{
+	target=$1
+	format=$2
+	want=$3
+	i=0
+	while [ "$i" -lt 50 ]; do
+		got=$($INNER display-message -p -t "$target" "$format" \
+		    2>/dev/null)
+		[ "$got" = "$want" ] && return 0
+		sleep 0.1
+		i=$((i + 1))
+	done
+	fail "$target format $format is '$got', expected '$want'"
+}
+
+wait_client_session()
+{
+	want=$1
+	i=0
+	while [ "$i" -lt 50 ]; do
+		got=$($INNER list-clients -F '#{client_session}' 2>/dev/null)
+		[ "$got" = "$want" ] && return 0
+		sleep 0.1
+		i=$((i + 1))
+	done
+	fail "client session is '$got', expected '$want'"
+}
+
+# Three alphabetically ordered sessions. alpha:main has two panes so -Z can be
+# observed; the two pick-* windows make a deterministic two-row window filter.
+$INNER new-session -d -s alpha -n main -x60 -y15 'exec sleep 100' || exit 1
+$INNER split-window -d -h -t alpha:main 'exec sleep 100' || exit 1
+$INNER new-window -d -t alpha: -n pick-one 'exec sleep 100' || exit 1
+$INNER new-session -d -s bravo -n pick-two -x60 -y15 \
+	'exec sleep 100' || exit 1
+$INNER new-session -d -s charlie -n last -x60 -y15 \
+	'exec sleep 100' || exit 1
+$INNER set-option -g status off || exit 1
+$INNER set-option -g window-size manual || exit 1
+$INNER select-window -t alpha:main || exit 1
+
+$OUTER new-session -d -s outer -x60 -y15 "$INNER attach -t alpha" || exit 1
+$OUTER set-option -g status off || exit 1
+$OUTER set-option -g window-size manual || exit 1
+wait_client_session alpha
+
+# Session rows are sorted alpha, bravo, charlie. Up from the first row wraps to
+# charlie; Enter runs a custom command with the selected session target.
+$INNER set-option -g @picked '' || exit 1
+$INNER switch-mode -s -t alpha:main.0 -F 'SESSION #{session_name}' \
+	"set-option -g @picked '%%'" || exit 1
+wait_count 'SESSION ' 3
+$INNER send-keys -t alpha:main.0 Up Enter || exit 1
+wait_format alpha:main.0 '#{@picked}' '=charlie:'
+wait_format alpha:main.0 '#{pane_in_mode}' 0
+
+# Fuzzy filtering keeps only bravo for "brv". The default command switches the
+# real client to that session and closes the mode.
+$INNER switch-mode -s -t alpha:main.0 -F 'SESSION #{session_name}' || exit 1
+wait_count 'SESSION ' 3
+$INNER send-keys -t alpha:main.0 -l brv || exit 1
+wait_count 'SESSION ' 1
+printf '%s\n' "$captured" | grep -Fq 'SESSION bravo' ||
+	fail "fuzzy session filter did not select bravo"
+$INNER send-keys -t alpha:main.0 Enter || exit 1
+wait_client_session bravo
+client=$($INNER list-clients -F '#{client_name}')
+$INNER switch-client -c "$client" -t alpha || exit 1
+wait_client_session alpha
+
+# Window mode sees pick-one then pick-two for the "pick" filter. Down selects
+# the second row, and the custom command receives its window target.
+$INNER set-option -g @picked '' || exit 1
+$INNER switch-mode -w -t alpha:main.0 -F \
+	'WINDOW #{session_name}:#{window_name}' \
+	"set-option -g @picked '%%'" || exit 1
+wait_capture 'WINDOW '
+$INNER send-keys -t alpha:main.0 -l pick || exit 1
+wait_count 'WINDOW ' 2
+$INNER send-keys -t alpha:main.0 Down Enter || exit 1
+picked=$($INNER show-option -gv @picked)
+case "$picked" in
+=bravo:0.) ;;
+*) fail "window selection produced '$picked', expected '=bravo:0.'" ;;
+esac
+
+# Navigation with an empty result set must be harmless, and Escape cancels
+# without running the custom command.
+$INNER set-option -g @picked unchanged || exit 1
+$INNER switch-mode -s -t alpha:main.0 -F 'NONE #{session_name}' \
+	"set-option -g @picked '%%'" || exit 1
+wait_capture 'NONE '
+$INNER send-keys -t alpha:main.0 -l no-such-session || exit 1
+wait_count 'NONE ' 0
+$INNER send-keys -t alpha:main.0 Up Down PPage NPage Home End || exit 1
+wait_format alpha:main.0 '#{pane_mode}' switch-mode
+$INNER send-keys -t alpha:main.0 Escape || exit 1
+wait_format alpha:main.0 '#{pane_in_mode}' 0
+[ "$($INNER show-option -gv @picked)" = unchanged ] ||
+	fail "cancelled switch-mode ran its command"
+
+# -Z temporarily zooms an unzoomed window. Resizing while the mode is open
+# rebuilds and redraws it; exiting restores the original unzoomed state.
+$INNER switch-mode -Zs -t alpha:main.0 -F 'RESIZE #{session_name}' || exit 1
+wait_capture 'RESIZE alpha'
+wait_format alpha:main.0 '#{window_zoomed_flag}' 1
+$INNER resize-window -t alpha:main -x50 -y12 || exit 1
+wait_format alpha:main.0 '#{window_width}x#{window_height}' 50x12
+wait_format alpha:main.0 '#{pane_mode}' switch-mode
+$INNER send-keys -t alpha:main.0 Escape || exit 1
+wait_format alpha:main.0 '#{window_zoomed_flag}' 0
+
+# If the window was already zoomed, leaving -Z mode must keep it zoomed.
+$INNER resize-pane -Z -t alpha:main.0 || exit 1
+$INNER switch-mode -Zs -t alpha:main.0 -F 'ZOOMED #{session_name}' || exit 1
+wait_capture 'ZOOMED alpha'
+$INNER send-keys -t alpha:main.0 Escape || exit 1
+wait_format alpha:main.0 '#{window_zoomed_flag}' 1
+$INNER resize-pane -Z -t alpha:main.0 || exit 1
+
+# -k uses the shared mode teardown flag. Put it on a disposable pane and make
+# sure exiting the mode removes that pane.
+kill_pane=$($INNER split-window -d -P -F '#{pane_id}' -t alpha:main \
+	'exec sleep 100') || exit 1
+$INNER switch-mode -ks -t "$kill_pane" -F 'KILL #{session_name}' || exit 1
+wait_format "$kill_pane" '#{pane_mode}' switch-mode
+$INNER send-keys -t "$kill_pane" Escape || exit 1
+i=0
+while [ "$i" -lt 50 ]; do
+	$INNER list-panes -s -t alpha -F '#{pane_id}' 2>/dev/null | \
+	    grep -q -x "$kill_pane" || break
+	sleep 0.1
+	i=$((i + 1))
+done
+[ "$i" -lt 50 ] || fail "switch-mode -k did not kill its pane"
+
+exit 0

regress/sync-output-atomic.sh

@@ -14,8 +14,8 @@ DIR=$(mktemp -d) || exit 1
 TMUX_TMPDIR=$DIR
 export TMUX_TMPDIR
 
-INNER="$TEST_TMUX -Lsync-output-inner-$$ -f/dev/null"
-OUTER="$TEST_TMUX -Lsync-output-outer-$$ -f/dev/null"
+INNER="$TEST_TMUX -Li$$ -f/dev/null"
+OUTER="$TEST_TMUX -Lo$$ -f/dev/null"
 CLIENT_BYTES=$DIR/client-bytes
 CONTROL=$DIR/control
 EMITTER=$DIR/emitter.pl
@@ -112,7 +112,7 @@ $INNER set-option -g window-size manual || exit 1
 $INNER set-option -as terminal-features '*:sync' || exit 1
 
 $OUTER new-session -d -s outer -x 80 -y 24 \
-    "$TEST_TMUX -Lsync-output-inner-$$ -f/dev/null attach-session -t inner" ||
+    "$TEST_TMUX -Li$$ -f/dev/null attach-session -t inner" ||
     exit 1
 $OUTER set-option -g status off || exit 1
 $OUTER set-option -g window-size manual || exit 1

regress/sync-output-cursor.sh

@@ -0,0 +1,160 @@
+#!/bin/sh
+
+# A synchronized update elsewhere in the pane must not hide a stationary
+# cursor while tmux waits for the end of the update.
+
+PATH=/bin:/usr/bin
+TERM=screen
+LC_ALL=C.UTF-8
+export PATH TERM LC_ALL
+
+[ -z "$TEST_TMUX" ] && TEST_TMUX=$(readlink -f ../tmux)
+
+if [ "$#" -eq 0 ]; then
+	TEST_TMUX="$TEST_TMUX" sh "$0" pane || exit 1
+	TEST_TMUX="$TEST_TMUX" sh "$0" prompt || exit 1
+	exit 0
+fi
+case $1 in
+pane|prompt) MODE=$1 ;;
+*) echo "usage: $0 [pane|prompt]" >&2; exit 1 ;;
+esac
+
+DIR=$(mktemp -d) || exit 1
+TMUX_TMPDIR=$DIR
+export TMUX_TMPDIR
+
+INNER="$TEST_TMUX -Li$$ -f/dev/null"
+OUTER="$TEST_TMUX -Lo$$ -f/dev/null"
+CLIENT_BYTES=$DIR/client-bytes
+CONTROL=$DIR/control
+EMITTER=$DIR/emitter.pl
+ASSERT=$DIR/assert-cursor.pl
+
+fail()
+{
+	echo "$*" >&2
+	exit 1
+}
+
+cleanup()
+{
+	$OUTER kill-server 2>/dev/null
+	$INNER kill-server 2>/dev/null
+	rm -rf "$DIR"
+}
+trap cleanup 0 1 15
+
+wait_for_client()
+{
+	i=0
+	while [ "$i" -lt 50 ]; do
+		$INNER list-clients -F '#{client_termfeatures}' 2>/dev/null |
+		    grep -q 'sync' && return 0
+		sleep 0.1
+		i=$((i + 1))
+	done
+	fail "sync-capable client did not attach"
+}
+
+cat >"$EMITTER" <<'PERL'
+use strict;
+use warnings;
+
+my $control = $ENV{CONTROL};
+(my $dir = $control) =~ s{/[^/]+$}{};
+
+# Draw a prompt and leave its cursor stationary on the last line.
+syswrite STDOUT, "\e[2J\e[HWorking .\e[24;1H> ";
+open my $ready, '>', "$dir/ready" or die "$dir/ready: $!\n";
+close $ready;
+while (!-e $control) {
+	select undef, undef, undef, 0.01;
+}
+
+# Deliberately split BSU, content, and ESU across pane reads. This mirrors an
+# animation producer which begins a frame before it has finished rendering it.
+for my $spinner (qw(| / - \\)) {
+	syswrite STDOUT, "\e[?2026h";
+	select undef, undef, undef, 0.05;
+	syswrite STDOUT, "\e[1;9H$spinner\e[24;3H";
+	select undef, undef, undef, 0.01;
+	syswrite STDOUT, "\e[?2026l";
+	select undef, undef, undef, 0.15;
+}
+select undef, undef, undef, 5;
+PERL
+
+cat >"$ASSERT" <<'PERL'
+use strict;
+use warnings;
+
+my $path = shift;
+open my $fh, '<:raw', $path or die "$path: $!\n";
+local $/;
+my $bytes = <$fh>;
+my ($bsu, $esu, $hide, $show) =
+    ("\e[?2026h", "\e[?2026l", "\e[?25l", "\e[?25h");
+my ($sync, $outside, $hides, $shows) = (0, 0, 0, 0);
+
+for (my $i = 0; $i < length($bytes);) {
+	if (substr($bytes, $i, length($bsu)) eq $bsu) {
+		$sync++;
+		$i += length($bsu);
+		next;
+	}
+	if (substr($bytes, $i, length($esu)) eq $esu) {
+		$sync-- if $sync;
+		$i += length($esu);
+		next;
+	}
+	if (substr($bytes, $i, length($hide)) eq $hide) {
+		$hides++;
+		$outside++ unless $sync;
+		$i += length($hide);
+		next;
+	}
+	if (substr($bytes, $i, length($show)) eq $show) {
+		$shows++;
+		$outside++ unless $sync;
+		$i += length($show);
+		next;
+	}
+	$i++;
+}
+
+printf "%s cursor hides: %d; cursor shows: %d; changes outside sync: %d\n",
+    $ENV{MODE}, $hides, $shows, $outside;
+die "stationary cursor changed outside synchronized output\n" if $outside;
+PERL
+
+$INNER new-session -d -s inner -x 80 -y 24 \
+    "CONTROL='$CONTROL' perl '$EMITTER'" || exit 1
+$INNER set-option -g status off || exit 1
+$INNER set-option -g window-size manual || exit 1
+$INNER set-option -as terminal-features '*:sync' || exit 1
+
+$OUTER new-session -d -s outer -x 80 -y 24 \
+    "$TEST_TMUX -Li$$ -f/dev/null attach-session -t inner" || exit 1
+$OUTER set-option -g status off || exit 1
+$OUTER set-option -g window-size manual || exit 1
+wait_for_client
+
+if [ "$MODE" = prompt ]; then
+	$OUTER send-keys -t outer:0.0 C-b : || exit 1
+	sleep 0.2
+fi
+
+i=0
+while [ "$i" -lt 50 ] && [ ! -e "$DIR/ready" ]; do
+	sleep 0.1
+	i=$((i + 1))
+done
+[ -e "$DIR/ready" ] || fail "application emitter did not become ready"
+
+$OUTER pipe-pane -O -t outer:0.0 "cat >'$CLIENT_BYTES'" || exit 1
+: >"$CONTROL"
+sleep 2
+$OUTER pipe-pane -t outer:0.0 || exit 1
+
+MODE=$MODE perl "$ASSERT" "$CLIENT_BYTES"

regress/targets-panes.sh

@@ -97,6 +97,10 @@ check "p:.{top-left}" "%0"
 check_ok select-pane -t p:0.%0
 check "p:0.+" "1" '#{pane_index}'	# next pane
 check "p:0.-" "3" '#{pane_index}'	# previous pane (wraps)
+check_fail "can't find pane: +0" "p:0.+0"
+check_fail "can't find pane: +foo" "p:0.+foo"
+check_fail "can't find pane: -0" "p:0.-0"
+check_fail "can't find pane: -foo" "p:0.-foo"
 
 # --- last pane (!) --------------------------------------------------------
 check_ok select-pane -t p:0.%2

regress/targets.sh

@@ -154,6 +154,13 @@ check "alpha:{previous}" "3"
 check "alpha:!" "2"		# last window
 check "alpha:{last}" "2"
 
+# Malformed relative offsets must fail rather than silently selecting the
+# current window.
+check_fail "can't find window: +0" "alpha:+0"
+check_fail "can't find window: +foo" "alpha:+foo"
+check_fail "can't find window: -0" "alpha:-0"
+check_fail "can't find window: -foo" "alpha:-foo"
+
 # --- combined and empty forms ---------------------------------------------
 #
 # Empty targets use the current pane from TMUX_PANE when there is no client.

regress/terminal-feature-utf8.sh

@@ -0,0 +1,58 @@
+#!/bin/sh
+
+# The utf8 terminal feature must mark an attached client as UTF-8 even when
+# neither its environment nor -u does so. It must also be reported by the
+# client terminal-feature format lookup.
+
+PATH=/bin:/usr/bin
+TERM=screen
+LC_ALL=C.UTF-8
+export PATH TERM LC_ALL
+
+[ -z "$TEST_TMUX" ] && TEST_TMUX=$(readlink -f ../tmux)
+INNER="$TEST_TMUX -LtestI$$ -f/dev/null"
+OUTER="$TEST_TMUX -LtestO$$ -f/dev/null"
+
+fail()
+{
+	echo "$*" >&2
+	exit 1
+}
+
+cleanup()
+{
+	$OUTER kill-server 2>/dev/null
+	$INNER kill-server 2>/dev/null
+}
+trap cleanup 0 1 15
+
+cleanup
+$INNER new-session -d -s inner -x40 -y10 'exec sleep 100' || exit 1
+$INNER set-option -g status off || exit 1
+
+# A clean C-locale environment avoids the ordinary UTF-8 detection paths.
+# -T utf8 is therefore solely responsible for setting client_utf8.
+client_command="env -i PATH=/bin:/usr/bin TERM=screen LC_ALL=C $TEST_TMUX -T utf8 -LtestI$$ -f/dev/null attach-session -t inner"
+$OUTER new-session -d -s outer -x40 -y10 "$client_command" || exit 1
+$OUTER set-option -g status off || exit 1
+
+i=0
+while [ "$i" -lt 50 ]; do
+	client=$($INNER list-clients -F '#{client_name}' 2>/dev/null)
+	utf8=$($INNER list-clients -F '#{client_utf8}' 2>/dev/null)
+	[ -n "$client" ] && [ "$utf8" = 1 ] && break
+	sleep 0.1
+	i=$((i + 1))
+done
+[ "$i" -lt 50 ] || fail "utf8 terminal feature did not set client_utf8"
+
+features=$($INNER list-clients -F '#{client_termfeatures}')
+case ",$features," in
+*,utf8,*) ;;
+*) fail "utf8 is missing from client_termfeatures: $features" ;;
+esac
+
+present=$($INNER display-message -c "$client" -p '#{I/f:utf8}')
+[ "$present" = 1 ] || fail "utf8 terminal feature lookup returned '$present'"
+
+exit 0

regress/tty-draw-line.sh

@@ -105,6 +105,21 @@ sleep 1
 CLIENT=$($TMUX2 list-clients -F '#{client_name}' | head -1)
 [ -n "$CLIENT" ] || fail "no inner client"
 
+# A variation selector which widens the previous character must use window
+# coordinates when checking visibility in a pane with a nonzero x offset.
+$TMUX2 set -s variation-selector-always-wide on || exit 1
+WINDOW=$($TMUX2 neww -dPF '#{window_id}' "exec sleep 100") || exit 1
+PANE=$($TMUX2 splitw -dhPF '#{pane_id}' -t "$WINDOW" \
+	"exec sleep 100") || exit 1
+$TMUX2 selectw -t "$WINDOW" || exit 1
+$TMUX2 respawnp -k -t "$PANE" \
+	"printf '\nA\342\234\217\357\270\217B'; exec sleep 100" || exit 1
+sleep 1
+$TMUX2 capturep -p -t "$PANE" >$TMP || exit 1
+EXPECTED=$(printf 'A\342\234\217\357\270\217B')
+check_line 2 "$EXPECTED"
+$TMUX2 killw -t "$WINDOW" || exit 1
+
 # Long line, then short line: default cells after cellsize must clear stale text.
 capture
 check_line 1 "abcdefghijklmnopqrst"

regress/window-ops.sh

@@ -8,7 +8,7 @@
 # This exercises:
 # - new-window placement: next free index, explicit index, index in use with
 #   and without -k, -a (after) and -b (before) insertion with shuffling, and
-#   -S selecting an existing window by name instead of creating;
+#   -S selecting an existing window by name or target instead of creating;
 # - move-window to a free index, to an occupied index with and without -k,
 #   -a insertion and -r renumbering (including base-index);
 # - renumber-windows closing gaps;
@@ -17,7 +17,8 @@
 #   unlink the last link without -k;
 # - swap-window within and between sessions, -d keeping the active window,
 #   and the grouped-sessions error;
-# - rotate-window -U/-D rotating pane positions;
+# - rotate-window -U/-D rotating pane positions, with and without preserving
+#   zoom using -Z;
 # - kill-window switching to the last (previously current) window, kill-window
 #   -a killing all other windows and the "-f only valid with -a" guard.
 #
@@ -139,6 +140,36 @@ check_ok new-window -S -t W: -n w3
 check_windows W '0:wB 1:w0 2:w1 3:wA 4:w2 5:w3 9:w9k'
 check_fmt 'W:' '#{window_index}:#{window_name}' '5:w3'
 
+# -S with a target-window that already exists selects it directly, ignoring
+# -n (with -d it does not switch).
+check_ok select-window -t W:0
+check_ok new-window -S -t W:9 -n ignored
+check_windows W '0:wB 1:w0 2:w1 3:wA 4:w2 5:w3 9:w9k'
+check_fmt 'W:' '#{window_index}:#{window_name}' '9:w9k'
+check_ok select-window -t W:0
+check_ok new-window -S -d -t W:9 -n ignored
+check_windows W '0:wB 1:w0 2:w1 3:wA 4:w2 5:w3 9:w9k'
+check_fmt 'W:' '#{window_index}:#{window_name}' '0:wB'
+
+# -S with a target-window that does not yet exist still creates it normally.
+check_ok new-window -S -t W:20 -n w20
+check_windows W '0:wB 1:w0 2:w1 3:wA 4:w2 5:w3 9:w9k 20:w20'
+check_fmt 'W:' '#{window_index}:#{window_name}' '20:w20'
+check_ok kill-window -t W:20
+
+# -S also works with a relative target-window (+N): selects the window at
+# that offset if it exists, or creates it there if not.
+check_ok select-window -t W:0
+check_ok new-window -S -t W:+1
+check_fmt 'W:' '#{window_index}:#{window_name}' '1:w0'
+check_windows W '0:wB 1:w0 2:w1 3:wA 4:w2 5:w3 9:w9k'
+
+check_ok select-window -t W:0
+check_ok new-window -S -t W:+6 -n rel6
+check_fmt 'W:' '#{window_index}:#{window_name}' '6:rel6'
+check_windows W '0:wB 1:w0 2:w1 3:wA 4:w2 5:w3 6:rel6 9:w9k'
+check_ok kill-window -t W:6
+
 # Clean up to a known arrangement.
 check_ok kill-window -t W:wB
 check_ok kill-window -t W:wA
@@ -306,6 +337,24 @@ check_fmt 'R:0' '#{pane_index}:#{pane_id}' "0:$p1"
 check_ok rotate-window -D -t R:0
 check_fmt 'R:0' '#{pane_index}:#{pane_id}' "0:$p0"
 
+# Rotation without -Z unzooms. With -Z it preserves zoom and transfers it to
+# the pane which arrives at the active position.
+layout=$($TMUX display-message -p -t R:0 '#{window_layout}')
+check_ok resize-pane -Z -t "$p0"
+check_ok rotate-window -U -t R:0
+check_fmt "$p1" '#{window_zoomed_flag}:#{pane_zoomed_flag}:#{pane_active}' \
+	'0:0:1'
+check_ok rotate-window -D -t R:0
+check_fmt 'R:0' '#{window_layout}' "$layout"
+
+check_ok resize-pane -Z -t "$p0"
+check_ok rotate-window -U -Z -t R:0
+check_fmt "$p1" '#{window_zoomed_flag}:#{pane_zoomed_flag}:#{pane_active}' \
+	'1:1:1'
+check_ok resize-pane -Z -t "$p1"
+check_ok rotate-window -D -t R:0
+check_fmt 'R:0' '#{window_layout}' "$layout"
+
 # ---------------------------------------------------------------------------
 # kill-window.
 

resize.c

@@ -1,4 +1,4 @@
-/* $OpenBSD: resize.c,v 1.58 2026/07/17 08:37:29 nicm Exp $ */
+/* $OpenBSD: resize.c,v 1.59 2026/08/20 09:19:24 nicm Exp $ */
 
 /*
  * Copyright (c) 2007 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -42,8 +42,8 @@ resize_fire_window_resized(struct window *w, u_int old_sx, u_int old_sy)
 void
 resize_window(struct window *w, u_int sx, u_int sy, int xpixel, int ypixel)
 {
-	u_int	old_sx = w->sx, old_sy = w->sy;
-	int	zoomed;
+	struct window_pane	*zwp;
+	u_int			 old_sx = w->sx, old_sy = w->sy;
 
 	/* Check size limits. */
 	if (sx < WINDOW_MINIMUM)
@@ -56,8 +56,8 @@ resize_window(struct window *w, u_int sx, u_int sy, int xpixel, int ypixel)
 		sy = WINDOW_MAXIMUM;
 
 	/* If the window is zoomed, unzoom. */
-	zoomed = w->flags & WINDOW_ZOOMED;
-	if (zoomed)
+	zwp = window_zoomed_pane(w);
+	if (zwp != NULL)
 		window_unzoom(w, 1);
 
 	/* Resize the layout first. */
@@ -73,8 +73,8 @@ resize_window(struct window *w, u_int sx, u_int sy, int xpixel, int ypixel)
 	    sx, sy, w->layout_root->g.sx, w->layout_root->g.sy);
 
 	/* Restore the window zoom state. */
-	if (zoomed)
-		window_zoom(w->active);
+	if (zwp != NULL && window_has_pane(w, zwp))
+		window_zoom(zwp);
 
 	tty_update_window_offset(w);
 	server_redraw_window(w);
@@ -386,12 +386,10 @@ recalculate_size(struct window *w, int now)
 	 * got a resize scheduled, then use the new size; otherwise the old.
 	 */
 	if (w->flags & WINDOW_RESIZE) {
-		if (!now && changed && w->new_sx == sx && w->new_sy == sy &&
-		    w->new_xpixel == xpixel && w->new_ypixel == ypixel)
+		if (!now && changed && w->new_sx == sx && w->new_sy == sy)
 			changed = 0;
 	} else {
-		if (!now && changed && w->sx == sx && w->sy == sy &&
-		    w->xpixel == xpixel && w->ypixel == ypixel)
+		if (!now && changed && w->sx == sx && w->sy == sy)
 			changed = 0;
 	}