Update CHANGES and tests.

whinging about not supporting it, GitHub issue 5626 from Pete Dietl.

.github/workflows/lock.yml

@@ -16,8 +16,10 @@ concurrency:
 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

@@ -16,7 +16,8 @@ jobs:
   regress:
     name: ${{ matrix.name }}
     runs-on: ${{ matrix.runner }}
-    timeout-minutes: 45
+    if: github.repository == 'tmux/tmux'
+    timeout-minutes: 300
 
     strategy:
       fail-fast: false
@@ -37,7 +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'
@@ -76,11 +79,11 @@ jobs:
       - name: test
         run: |
           cd regress
-          ${{ matrix.make }}
+          ${{ matrix.make }} -j"$(getconf _NPROCESSORS_ONLN)"
 
       - 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

@@ -1,7 +1,4 @@
-CHANGES FROM 3.7b TO 3.8
+CHANGES FROM 3.7c TO 3.8
-
-* Build with jemalloc on macOS to avoid what appears to be a bug in the system
-  calloc(3) (issue 5385).
 
 * Many improvements to floating panes:
 
@@ -12,7 +9,12 @@ CHANGES FROM 3.7b 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. -D closes the modal pane with
+    Escape or C-c. 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;
@@ -27,10 +29,18 @@ CHANGES FROM 3.7b 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
+  - command-prompt -P opens a prompt inside a pane rather than on the status
-    default bindings under C-b g for common move and resize operations;
+    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 remain-on-exit failed-key to keep a pane open after a failed command
+  until a key is pressed.
 
 * Add support for themes and improve default colours:
 
@@ -77,7 +87,7 @@ CHANGES FROM 3.7b 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.
@@ -90,10 +100,29 @@ CHANGES FROM 3.7b 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
+* Add a clear-on-attach server option. When disabled, tmux does not enter the
-  changed.
+  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 an appesc terminal feature for mintty's application escape key mode,
+  avoiding unsupported sequences on other terminals (Pete Dietl, issue 5626).
+
+* Preserve existing Ss and Se terminfo capabilities for cursor styles and
+  restoring the default cursor (issue 5476).
 
 * Add a #{A/count:frames} modifier to show a series of frames as an animation
   in the status line (issue 5412 from Fernando Daciuk).
@@ -108,6 +137,12 @@ CHANGES FROM 3.7b 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).
@@ -121,7 +156,12 @@ CHANGES FROM 3.7b TO 3.8
 * Copy mode no longer exits at the bottom while a selection is in progress
   (issue 5349).
 
-* Fix scrollbar initial state so scrollbars appear on new windows (issue 5339).
+* 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).
@@ -133,7 +173,9 @@ CHANGES FROM 3.7b 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.
@@ -145,15 +187,34 @@ CHANGES FROM 3.7b 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), and
+  fix a collision between the output discard and bracketed paste flags (issue
+  5622).
 
 * Fix grouped sessions sometimes being left as unusable command targets while
-  they are being killed (Bryce Miller, issue 5180).
+  they are being killed (Bryce Miller, issue 5180), and prevent reuse of a
+  session with no windows while detaching (Heon Jeong, issue 5620).
+
+* Free wait-for clients when they disconnect and do not run their remaining
+  queued commands (issue 5614).
+
+* Expand formats in run-shell -c like other start-directory flags (reported by
+  Saul Nogueras).
+
+* Fix session alert flag formats to check all windows (issue 5599).
+
+* Do not clear the marked pane when clicking on a pane border.
 
 * Fix choose mode filtering when more than one pane exists (issue 5326), and
   fix an infinite loop in customize mode when a filter does not match.
@@ -164,12 +225,30 @@ CHANGES FROM 3.7b TO 3.8
   status lines, menus, popups, wide characters and floating panes. This
   includes fixes for flicker with alternate screen applications and scrollbars
   (Michael Grant, issue 5351; Noam Stolero, issue 5350; Aung Myo Kyaw, issue
-  5098).
+  5098), and misplaced wrapped lines during partial redraws (Ben Maurer, issue
+  5625).
 
 * Do not crash looking for the next or previous session (issue 5344), or when
   no client is available.
 
-* Check time periodically in loops rather than for every item (issue 5367).
+* Fix crashes when destroying a zoomed pane (Romain Francoise, issue 5591),
+  copying from a blank source pane (Kaixuan Li), or opening a mode prompt when
+  the client is offset into the window.
+
+* Avoid an infinite loop when assigning a width to WCHAR_MAX (issue 5602).
+
+CHANGES FROM 3.7b TO 3.7c
+
+* Build with jemalloc on macOS to avoid what appears to be a bug in calloc
+  (issue 5385).
+
+* Fix scrollbar initial state so they appear on new windows (issue 5339).
+
+* Check time periodically in loops rather than every one (issue 5367).
+
+* Use message-style again as default for message-format.
+
+* Unzoom before creating floating panes to avoid a crash.
 
 CHANGES FROM 3.7a TO 3.7b
 

Makefile.am

@@ -174,6 +174,7 @@ dist_tmux_SOURCES = \
 	input-keys.c \
 	input.c \
 	job.c \
+	json.c \
 	key-bindings.c \
 	key-string.c \
 	layout-custom.c \

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));
 	}
 

cfg.c

@@ -1,4 +1,4 @@
-/* $OpenBSD: cfg.c,v 1.90 2026/07/14 17:17:17 nicm Exp $ */
+/* $OpenBSD: cfg.c,v 1.91 2026/08/03 13:38:42 nicm Exp $ */
 
 /*
  * Copyright (c) 2008 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -223,13 +223,15 @@ cfg_print_causes(struct cmdq_item *item)
 {
 	struct client	*c = cmdq_get_client(item);
 	u_int		 i;
+	char		*cause;
 
 	for (i = 0; i < cfg_ncauses; i++) {
+		cause = cfg_causes[i];
 		if (c != NULL && (c->flags & CLIENT_CONTROL))
-			control_write(c, "%%config-error %s", cfg_causes[i]);
+			control_notify_write(c, "%%config-error %s", cause);
 		else
-			cmdq_print(item, "%s", cfg_causes[i]);
+			cmdq_print(item, "%s", cause);
-		free(cfg_causes[i]);
+		free(cause);
 	}
 
 	free(cfg_causes);
@@ -244,14 +246,16 @@ cfg_show_causes(struct session *s)
 	struct window_pane		*wp;
 	struct window_mode_entry	*wme;
 	u_int				 i;
+	char				*cause;
 
 	if (cfg_ncauses == 0)
 		return;
 
 	if (c != NULL && (c->flags & CLIENT_CONTROL)) {
 		for (i = 0; i < cfg_ncauses; i++) {
-			control_write(c, "%%config-error %s", cfg_causes[i]);
+			cause = cfg_causes[i];
-			free(cfg_causes[i]);
+			control_notify_write(c, "%%config-error %s", cause);
+			free(cause);
 		}
 		goto out;
 	}

client.c

@@ -1,4 +1,4 @@
-/* $OpenBSD: client.c,v 1.166 2026/07/10 15:45:11 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>
@@ -276,7 +276,7 @@ client_main(struct event_base *base, int argc, char **argv, uint64_t flags,
 	proc_set_signals(client_proc, client_signal);
 
 	/* Save the flags. */
-	client_flags = flags;
+	client_flags = flags|CLIENT_WRITE_ACK;
 	log_debug("flags are %#llx", (unsigned long long)client_flags);
 
 	/* Initialize the client socket and start the server. */
@@ -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-break-pane.c

@@ -1,4 +1,4 @@
-/* $OpenBSD: cmd-break-pane.c,v 1.75 2026/07/23 09:38:27 nicm Exp $ */
+/* $OpenBSD: cmd-break-pane.c,v 1.76 2026/08/17 07:04:45 nicm Exp $ */
 
 /*
  * Copyright (c) 2009 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -174,13 +174,14 @@ cmd_break_pane_exec(struct cmd *self, struct cmdq_item *item)
 	}
 	window_set_fill_cells(w);
 
+	if (idx == -1)
+		idx = -1 - options_get_number(dst_s->options, "base-index");
+	wl = session_attach(dst_s, w, idx, &cause); /* can't fail */
+
 	layout_init(w, wp);
 	wp->flags |= PANE_CHANGED;
 	colour_palette_from_option(&wp->palette, wp->options);
 
-	if (idx == -1)
-		idx = -1 - options_get_number(dst_s->options, "base-index");
-	wl = session_attach(dst_s, w, idx, &cause); /* can't fail */
 	window_remove_ref(w, __func__);
 	events_fire_window("window-created", w);
 	window_fire_pane_moved(wp, old_w, old_idx, w, wl->idx);

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 },
+	.args = { "ab:CeE:FHIJLMNpPqRS:Tt:", 0, 0, NULL },
-	.usage = "[-aCeFHJLMNpPqRT] " CMD_BUFFER_USAGE " [-E end-line] "
+	.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 },
+	.args = { "aCc:d:jlINpt:F:v", 0, 1, NULL },
-	.usage = "[-aCIlNpv] [-c target-client] [-d delay] [-F format] "
+	.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')
+		if (window[1] != '\0') {
-			n = strtonum(window + 1, 1, INT_MAX, NULL);
+			n = strtonum(window + 1, 1, INT_MAX, &errstr);
-		else
+			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')
+		if (pane[1] != '\0') {
-			n = strtonum(pane + 1, 1, INT_MAX, NULL);
+			n = strtonum(pane + 1, 1, INT_MAX, &errstr);
-		else
+			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-join-pane.c

@@ -1,4 +1,4 @@
-/* $OpenBSD: cmd-join-pane.c,v 1.73 2026/07/17 15:24:30 nicm Exp $ */
+/* $OpenBSD: cmd-join-pane.c,v 1.75 2026/09/21 10:33:16 nicm Exp $ */
 
 /*
  * Copyright (c) 2011 George Nachman <tmux@georgester.com>
@@ -133,7 +133,7 @@ cmd_join_pane_place(struct cmdq_item *item, struct winlink *wl,
 	} else if (strcmp(position, "back") == 0) {
 		TAILQ_REMOVE(&w->z_index, wp, zentry);
 		TAILQ_FOREACH(owp, &w->z_index, zentry) {
-			if (!window_pane_is_floating(owp))
+			if (!window_pane_is_floating_with_hidden(owp))
 				break;
 		}
 		if (owp != NULL)
@@ -142,24 +142,30 @@ cmd_join_pane_place(struct cmdq_item *item, struct winlink *wl,
 			TAILQ_INSERT_TAIL(&w->z_index, wp, zentry);
 	} else if (strcmp(position, "forward") == 0) {
 		owp = TAILQ_PREV(wp, window_panes_zindex, zentry);
+		while (owp != NULL && owp->layout_cell == NULL)
+			owp = TAILQ_PREV(owp, window_panes_zindex, zentry);
 		if (owp != NULL) {
 			TAILQ_REMOVE(&w->z_index, wp, zentry);
 			TAILQ_INSERT_BEFORE(owp, wp, zentry);
 		}
 	} else if (strcmp(position, "backward") == 0) {
 		owp = TAILQ_NEXT(wp, zentry);
+		while (owp != NULL && owp->layout_cell == NULL)
+			owp = TAILQ_NEXT(owp, zentry);
 		if (owp != NULL && window_pane_is_floating(owp)) {
 			TAILQ_REMOVE(&w->z_index, wp, zentry);
 			TAILQ_INSERT_AFTER(&w->z_index, owp, wp, zentry);
 		}
 	} else if (strcmp(position, "forward-loop") == 0) {
 		owp = TAILQ_PREV(wp, window_panes_zindex, zentry);
+		while (owp != NULL && owp->layout_cell == NULL)
+			owp = TAILQ_PREV(owp, window_panes_zindex, zentry);
 		TAILQ_REMOVE(&w->z_index, wp, zentry);
 		if (owp != NULL)
 			TAILQ_INSERT_BEFORE(owp, wp, zentry);
 		else {
 			TAILQ_FOREACH(owp, &w->z_index, zentry) {
-				if (!window_pane_is_floating(owp))
+				if (!window_pane_is_floating_with_hidden(owp))
 					break;
 			}
 			if (owp != NULL)
@@ -169,6 +175,8 @@ cmd_join_pane_place(struct cmdq_item *item, struct winlink *wl,
 		}
 	} else if (strcmp(position, "backward-loop") == 0) {
 		owp = TAILQ_NEXT(wp, zentry);
+		while (owp != NULL && owp->layout_cell == NULL)
+			owp = TAILQ_NEXT(owp, zentry);
 		if (owp != NULL && window_pane_is_floating(owp)) {
 			TAILQ_REMOVE(&w->z_index, wp, zentry);
 			TAILQ_INSERT_AFTER(&w->z_index, owp, wp, zentry);
@@ -347,8 +355,10 @@ cmd_join_pane_zindex(struct cmdq_item *item, struct winlink *wl,
 
 	n = 0;
 	TAILQ_FOREACH(owp, &w->z_index, zentry) {
-		if (!window_pane_is_floating(owp))
+		if (!window_pane_is_floating_with_hidden(owp))
 			break;
+		if (owp->layout_cell == NULL)
+			continue;
 		if (n >= z)
 			break;
 		n++;
@@ -431,25 +441,22 @@ cmd_join_pane_exec(struct cmd *self, struct cmdq_item *item)
 	if (cmd_get_entry(self) == &cmd_move_pane_entry) {
 		if (args_has(args, 'M'))
 			return (cmd_join_pane_mouse_update(item));
-		if (!window_pane_is_floating(dst_wp)) {
+		if (args_has(args, 'P') ||
-			cmdq_error(item, "pane is not floating");
+		    args_has(args, 'z') ||
-			return (CMD_RETURN_ERROR);
+		    args_has(args, 'X') ||
-		}
-		if ((s = args_get(args, 'P')) != NULL) {
-			server_unzoom_window(dst_w);
-			return (cmd_join_pane_place(item, dst_wl, dst_wp, s));
-		}
-		if ((s = args_get(args, 'z')) != NULL) {
-			server_unzoom_window(dst_w);
-			return (cmd_join_pane_zindex(item, dst_wl, dst_wp, s));
-		}
-		if (args_has(args, 'X') ||
 		    args_has(args, 'Y') ||
 		    args_has(args, 'U') ||
 		    args_has(args, 'D') ||
 		    args_has(args, 'L') ||
 		    args_has(args, 'R')) {
-			server_unzoom_window(dst_w);
+			if (!window_pane_is_floating(dst_wp)) {
+				cmdq_error(item, "pane is not floating");
+				return (CMD_RETURN_ERROR);
+			}
+			if ((s = args_get(args, 'P')) != NULL)
+				return (cmd_join_pane_place(item, dst_wl, dst_wp, s));
+			if ((s = args_get(args, 'z')) != NULL)
+				return (cmd_join_pane_zindex(item, dst_wl, dst_wp, s));
 			return (cmd_join_pane_move(item, args, dst_wl, dst_wp));
 		}
 	}

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
+	 * If -S is given, select an existing window instead of creating a
-	 * name already exists, select it.
+	 * 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) {
@@ -88,7 +91,10 @@ 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) {
+	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)
@@ -97,12 +103,17 @@ cmd_new_window_exec(struct cmd *self, struct cmdq_item *item)
 					new_wl = wl;
 					continue;
 				}
-			cmdq_error(item, "multiple windows named %s", wname);
+				cmdq_error(item, "multiple windows named %s",
+				    wname);
 				free(wname);
 				free(expanded);
 				return (CMD_RETURN_ERROR);
 			}
 			free(expanded);
+		}
+	}
+
+	/* Found an existing window to select instead of creating a new one. */
 	if (new_wl != NULL) {
 		free(wname);
 		if (args_has(args, 'd'))
@@ -114,7 +125,6 @@ cmd_new_window_exec(struct cmd *self, struct cmdq_item *item)
 		recalculate_sizes();
 		return (CMD_RETURN_NORMAL);
 	}
-	}
 
 	before = args_has(args, 'b');
 	if (args_has(args, 'a') || before) {

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 1.121 2026/07/14 17:17:17 nicm Exp $ */
+/* $OpenBSD: cmd-queue.c,v 1.124 2026/09/22 06:46:50 nicm Exp $ */
 
 /*
  * Copyright (c) 2013 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -580,6 +580,9 @@ cmdq_fire_command(struct cmdq_item *item)
 	int			 flags, quiet = 0;
 	char			*tmp;
 
+	if (item->client != NULL && (item->client->flags & CLIENT_DEAD))
+		return (CMD_RETURN_ERROR);
+
 	if (cfg_finished)
 		cmdq_add_message(item);
 	if (log_get_level() > 1) {
@@ -802,7 +805,7 @@ cmdq_guard(struct cmdq_item *item, const char *guard, int flags)
 	u_int		 number = item->number;
 
 	if (c != NULL && (c->flags & CLIENT_CONTROL))
-		control_write(c, "%%%s %ld %u %d", guard, t, number, flags);
+		control_write_guard(c, guard, t, number, flags);
 }
 
 /* Show message from command. */
@@ -850,7 +853,18 @@ cmdq_error(struct cmdq_item *item, const char *fmt, ...)
 
 	if (c == NULL) {
 		cmd_get_source(cmd, &file, &line);
+		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 1.69 2026/09/21 10:33:16 nicm Exp $ */
 
 /*
  * Copyright (c) 2009 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -91,7 +91,9 @@ cmd_resize_pane_exec(struct cmd *self, struct cmdq_item *item)
 		server_redraw_window(w);
 		return (CMD_RETURN_NORMAL);
 	}
+	if (!window_pane_is_floating(wp))
 		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 1.95 2026/09/20 07:59:55 nicm Exp $ */
 
 /*
  * Copyright (c) 2009 Tiago Cunha <me@tiagocunha.org>
@@ -164,7 +164,7 @@ cmd_run_shell_exec(struct cmd *self, struct cmdq_item *item)
 	if (cdata->client != NULL)
 		cdata->client->references++;
 	if (args_has(args, 'c'))
-		cdata->cwd = xstrdup(args_get(args, 'c'));
+		cdata->cwd = format_single_from_target(item, args_get(args, 'c'));
 	else
 		cdata->cwd = xstrdup(server_client_get_cwd(c, s));
 
@@ -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;
+	char			*oldlayout, *cause = NULL;
-	int			 next, previous, layout;
+	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
+static void
-cmd_source_file_complete_cb(struct cmdq_item *item, __unused void *data)
+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 (!cfg_finished) {
+		cmd_source_file_free_data(cdata);
+		return;
+	}
+
 	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);
+	new_item = cmdq_get_callback(cmd_source_file_complete_cb, cdata);
 	cmdq_insert_after(cdata->after, new_item);
 }
 
-	for (i = 0; i < cdata->nfiles; i++)
-		free(cdata->files[i]);
-	free(cdata->files);
-	free(cdata);
-}
-
 static void
-cmd_source_file_done(struct client *c, const char *path, int error,
+cmd_source_file_done(__unused struct client *oc, const char *path,
-    int closed, struct evbuffer *buffer, void *data)
+    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 1.146 2026/07/21 12:28:43 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 },
+	.args = { "AbB:Cc:Dde:EfF:hIkl:KLMm:Op:PR:s:S:t:T:vWx:X:y:Y:Z", 0, -1, NULL },
-	.usage = "[-bCdefhIklMOPvWZ] [-B border-lines] "
+	.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;
@@ -96,9 +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 {
+		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;
 	}
@@ -132,7 +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'))
@@ -168,6 +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);
 	}
 
@@ -201,8 +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) {
@@ -270,7 +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);
 	}
@@ -321,8 +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) {

cmd-wait-for.c

@@ -1,4 +1,4 @@
-/* $OpenBSD: cmd-wait-for.c,v 1.23 2026/07/10 13:38:45 nicm Exp $ */
+/* $OpenBSD: cmd-wait-for.c,v 1.24 2026/09/22 06:46:50 nicm Exp $ */
 
 /*
  * Copyright (c) 2013 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -480,6 +480,40 @@ cmd_wait_for_unlock(struct cmdq_item *item, const char *name,
 	return (CMD_RETURN_NORMAL);
 }
 
+void
+cmd_wait_for_client_lost(struct client *c)
+{
+	struct wait_channel	*wc, *wc1;
+	struct wait_item	*wi, *wi1;
+	struct wait_event_item	*wei, *wei1;
+
+	TAILQ_FOREACH_SAFE(wei, &wait_event_items, entry, wei1) {
+		if (cmdq_get_client(wei->item) == c) {
+			TAILQ_REMOVE(&wait_event_items, wei, entry);
+			cmdq_continue(wei->item);
+			cmd_wait_for_event_free(wei);
+		}
+	}
+
+	RB_FOREACH_SAFE(wc, wait_channels, &wait_channels, wc1) {
+		TAILQ_FOREACH_SAFE(wi, &wc->waiters, entry, wi1) {
+			if (cmdq_get_client(wi->item) == c) {
+				cmdq_continue(wi->item);
+				TAILQ_REMOVE(&wc->waiters, wi, entry);
+				free(wi);
+			}
+		}
+		TAILQ_FOREACH_SAFE(wi, &wc->lockers, entry, wi1) {
+			if (cmdq_get_client(wi->item) == c) {
+				cmdq_continue(wi->item);
+				TAILQ_REMOVE(&wc->lockers, wi, entry);
+				free(wi);
+			}
+		}
+		cmd_wait_for_remove_empty(wc);
+	}
+}
+
 void
 cmd_wait_for_flush(void)
 {

compat/getpeereid.c

@@ -31,7 +31,7 @@ getpeereid(int s, uid_t *uid, gid_t *gid)
 {
 #ifdef HAVE_SO_PEERCRED
 	struct ucred	uc;
-	int		len = sizeof uc;
+	socklen_t	len = sizeof uc;
 
 	if (getsockopt(s, SOL_SOCKET, SO_PEERCRED, &uc, &len) == -1)
 		return (-1);

configure.ac

@@ -1,6 +1,6 @@
 # configure.ac
 
-AC_INIT([tmux], next-3.8)
+AC_INIT([tmux], 3.8-rc2)
 AC_PREREQ([2.60])
 
 AC_CONFIG_AUX_DIR(etc)

control-notify.c

@@ -1,4 +1,4 @@
-/* $OpenBSD: control-notify.c,v 1.37 2026/07/10 13:38:45 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>
@@ -44,7 +44,8 @@ control_pane_mode_changed_cb(__unused const char *name,
 		TAILQ_FOREACH(c, &clients, entry) {
 			if (!CONTROL_SHOULD_NOTIFY_CLIENT(c))
 				continue;
-			control_write(c, "%%pane-mode-changed %%%u", wp->id);
+			control_notify_write(c, "%%pane-mode-changed %%%u",
+			    wp->id);
 		}
 		return;
 	}
@@ -53,8 +54,9 @@ control_pane_mode_changed_cb(__unused const char *name,
 	if (value == NULL)
 		return;
 	TAILQ_FOREACH(c, &clients, entry) {
-		if (CONTROL_SHOULD_NOTIFY_CLIENT(c))
+		if (!CONTROL_SHOULD_NOTIFY_CLIENT(c))
-			control_write(c, "%%pane-mode-changed %s", value);
+			continue;
+		control_notify_write(c, "%%pane-mode-changed %s", value);
 	}
 	free(value);
 }
@@ -68,6 +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;
 
@@ -82,20 +85,26 @@ 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 (TAILQ_FIRST(&w->winlinks) == NULL || w->layout_root == NULL)
-	if (wl == 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)
+		wl = winlink_find_by_window_id(&s->windows, w->id);
-			control_write(c, "%s", cp);
+		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);
 	}
+}
 
 /* Notify control clients that window pane changed. */
 static void
@@ -111,7 +120,7 @@ control_window_pane_changed_cb(__unused const char *name,
 		if (!CONTROL_SHOULD_NOTIFY_CLIENT(c))
 			continue;
 
-		control_write(c, "%%window-pane-changed @%u %%%u", w->id,
+		control_notify_write(c, "%%window-pane-changed @%u %%%u", w->id,
 		    w->active->id);
 	}
 }
@@ -133,9 +142,11 @@ control_window_unlinked_cb(__unused const char *name, struct event_payload *ep,
 		cs = c->session;
 
 		if (winlink_find_by_window_id(&cs->windows, w->id) != NULL)
-			control_write(c, "%%window-close @%u", w->id);
+			control_notify_write(c, "%%window-close @%u", w->id);
-		else
+		else {
-			control_write(c, "%%unlinked-window-close @%u", w->id);
+			control_notify_write(c, "%%unlinked-window-close @%u",
+			    w->id);
+		}
 	}
 }
 
@@ -156,9 +167,11 @@ control_window_linked_cb(__unused const char *name, struct event_payload *ep,
 		cs = c->session;
 
 		if (winlink_find_by_window_id(&cs->windows, w->id) != NULL)
-			control_write(c, "%%window-add @%u", w->id);
+			control_notify_write(c, "%%window-add @%u", w->id);
-		else
+		else {
-			control_write(c, "%%unlinked-window-add @%u", w->id);
+			control_notify_write(c, "%%unlinked-window-add @%u",
+			    w->id);
+		}
 	}
 }
 
@@ -179,11 +192,11 @@ control_window_renamed_cb(__unused const char *name, struct event_payload *ep,
 		cs = c->session;
 
 		if (winlink_find_by_window_id(&cs->windows, w->id) != NULL) {
-			control_write(c, "%%window-renamed @%u %s", w->id,
+			control_notify_write(c, "%%window-renamed @%u %s",
-			    w->name);
-		} else {
-			control_write(c, "%%unlinked-window-renamed @%u %s",
 			    w->id, w->name);
+		} else {
+			control_notify_write(c,
+			    "%%unlinked-window-renamed @%u %s", w->id, w->name);
 		}
 	}
 }
@@ -206,11 +219,12 @@ control_client_session_changed_cb(__unused const char *name,
 			continue;
 
 		if (cc == c) {
-			control_write(c, "%%session-changed $%u %s", s->id,
+			control_notify_write(c, "%%session-changed $%u %s",
-			    s->name);
+			    s->id, s->name);
 		} else {
-			control_write(c, "%%client-session-changed %s $%u %s",
+			control_notify_write(c,
-			    cc->name, s->id, s->name);
+			    "%%client-session-changed %s $%u %s", cc->name,
+			    s->id, s->name);
 		}
 	}
 }
@@ -226,8 +240,9 @@ control_client_detached_cb(__unused const char *name, struct event_payload *ep,
 	if (cc == NULL)
 		return;
 	TAILQ_FOREACH(c, &clients, entry) {
-		if (CONTROL_SHOULD_NOTIFY_CLIENT(c))
+		if (!CONTROL_SHOULD_NOTIFY_CLIENT(c))
-			control_write(c, "%%client-detached %s", cc->name);
+			continue;
+		control_notify_write(c, "%%client-detached %s", cc->name);
 	}
 }
 
@@ -244,8 +259,8 @@ control_session_renamed_cb(__unused const char *name, struct event_payload *ep,
 	TAILQ_FOREACH(c, &clients, entry) {
 		if (!CONTROL_SHOULD_NOTIFY_CLIENT(c))
 			continue;
-
+		control_notify_write(c, "%%session-renamed $%u %s", s->id,
-		control_write(c, "%%session-renamed $%u %s", s->id, s->name);
+		    s->name);
 	}
 }
 
@@ -259,8 +274,7 @@ control_session_created_cb(__unused const char *name,
 	TAILQ_FOREACH(c, &clients, entry) {
 		if (!CONTROL_SHOULD_NOTIFY_CLIENT(c))
 			continue;
-
+		control_notify_write(c, "%%sessions-changed");
-		control_write(c, "%%sessions-changed");
 	}
 }
 
@@ -274,8 +288,7 @@ control_session_closed_cb(__unused const char *name,
 	TAILQ_FOREACH(c, &clients, entry) {
 		if (!CONTROL_SHOULD_NOTIFY_CLIENT(c))
 			continue;
-
+		control_notify_write(c, "%%sessions-changed");
-		control_write(c, "%%sessions-changed");
 	}
 }
 
@@ -298,9 +311,8 @@ control_session_window_changed_cb(__unused const char *name,
 	TAILQ_FOREACH(c, &clients, entry) {
 		if (!CONTROL_SHOULD_NOTIFY_CLIENT(c))
 			continue;
-
+		control_notify_write(c, "%%session-window-changed $%u @%u",
-		control_write(c, "%%session-window-changed $%u @%u", s->id,
+		    s->id, s->curw->window->id);
-		    s->curw->window->id);
 	}
 }
 
@@ -317,8 +329,7 @@ control_paste_buffer_changed_cb(__unused const char *name,
 	TAILQ_FOREACH(c, &clients, entry) {
 		if (!CONTROL_SHOULD_NOTIFY_CLIENT(c))
 			continue;
-
+		control_notify_write(c, "%%paste-buffer-changed %s", pbname);
-		control_write(c, "%%paste-buffer-changed %s", pbname);
 	}
 }
 
@@ -335,8 +346,7 @@ control_paste_buffer_deleted_cb(__unused const char *name,
 	TAILQ_FOREACH(c, &clients, entry) {
 		if (!CONTROL_SHOULD_NOTIFY_CLIENT(c))
 			continue;
-
+		control_notify_write(c, "%%paste-buffer-deleted %s", pbname);
-		control_write(c, "%%paste-buffer-deleted %s", pbname);
 	}
 }
 

control.c

@@ -1,4 +1,4 @@
-/* $OpenBSD: control.c,v 1.62 2026/07/17 08:37:29 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>
@@ -53,6 +53,17 @@ struct control_block {
 	TAILQ_ENTRY(control_block)	 all_entry;
 };
 
+/*
+ * A notification line deferred because it was generated while a command's
+ * %begin/%end guard block was open. Notifications must never appear inside a
+ * guard block, so they are held here and flushed once the block closes.
+ */
+struct control_line {
+	char				*line;
+
+	TAILQ_ENTRY(control_line)	 entry;
+};
+
 /* Control client pane. */
 struct control_pane {
 	u_int				 pane;
@@ -97,11 +108,19 @@ 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;
 
 	struct monitor_set		*subs;
+
+	/*
+	 * Depth of open %begin/%end guard blocks and notifications deferred
+	 * until the outermost block closes.
+	 */
+	int				 guard_depth;
+	TAILQ_HEAD(, control_line)	 deferred;
 };
 
 /* Low and high watermarks. */
@@ -114,6 +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| \
@@ -147,6 +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);
@@ -352,7 +383,7 @@ control_continue_pane(struct client *c, struct window_pane *wp)
 		cp->flags &= ~CONTROL_PANE_PAUSED;
 		memcpy(&cp->offset, &wp->offset, sizeof cp->offset);
 		memcpy(&cp->queued, &wp->offset, sizeof cp->queued);
-		control_write(c, "%%continue %%%u", wp->id);
+		control_notify_write(c, "%%continue %%%u", wp->id);
 	}
 }
 
@@ -366,52 +397,186 @@ control_pause_pane(struct client *c, struct window_pane *wp)
 	if (~cp->flags & CONTROL_PANE_PAUSED) {
 		cp->flags |= CONTROL_PANE_PAUSED;
 		control_discard_pane(c, cp);
-		control_write(c, "%%pause %%%u", wp->id);
+		control_notify_write(c, "%%pause %%%u", wp->id);
 	}
 }
 
-/* Write a line. */
+/*
-static void printflike(2, 0)
+ * Reset a pane after its buffer has been replaced: drop any output still
-control_vwrite(struct client *c, const char *fmt, va_list ap)
+ * 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;
-	char			*s;
+	size_t			 size;
 
-	xvasprintf(&s, fmt, ap);
+	if (c->flags & CLIENT_CONTROL_DISCARD)
-	log_debug("%s: %s: writing line: %s", __func__, c->name, s);
+		return (1);
+	size = EVBUFFER_LENGTH(cs->write_event->output);
+	size += cs->queued_reply_bytes;
+	size += added;
+	if (size < CONTROL_MAXIMUM_REPLY_BUFFER)
+		return (0);
 
-	bufferevent_write(cs->write_event, s, strlen(s));
+	log_debug("%s: %s: %zu bytes of replies buffered", __func__, c->name,
-	bufferevent_write(cs->write_event, "\n", 1);
+	    size);
-
+	if (~c->flags & CLIENT_EXIT) {
-	bufferevent_enable(cs->write_event, EV_WRITE);
+		c->exit_message = xstrdup("too far behind");
-	free(s);
+		c->flags |= CLIENT_EXIT;
+		control_discard(c);
+	}
+	c->flags |= CLIENT_CONTROL_DISCARD;
+	return (1);
 }
 
-/* Write a line. */
+/* Write an already-formatted line, queueing it behind %output if needed. */
-void
+static void
-control_write(struct client *c, const char *fmt, ...)
+control_write_line(struct client *c, char *line)
 {
 	struct control_state	*cs = c->control_state;
 	struct control_block	*cb;
-	va_list			 ap;
+	size_t			 size = strlen(line) + 1;
 
-	va_start(ap, fmt);
+	if (control_check_reply_buffer(c, size)) {
+		free(line);
+		return;
+	}
 
 	if (TAILQ_EMPTY(&cs->all_blocks)) {
-		control_vwrite(c, fmt, ap);
+		log_debug("%s: %s: writing line: %s", __func__, c->name, line);
-		va_end(ap);
+		bufferevent_write(cs->write_event, line, size - 1);
+		bufferevent_write(cs->write_event, "\n", 1);
+		bufferevent_enable(cs->write_event, EV_WRITE);
+		free(line);
 		return;
 	}
 
 	cb = xcalloc(1, sizeof *cb);
-	xvasprintf(&cb->line, fmt, ap);
+	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);
 	bufferevent_enable(cs->write_event, EV_WRITE);
+}
 
+/* Flush notifications that were deferred while a guard block was open. */
+static void
+control_flush_deferred(struct client *c)
+{
+	struct control_state	*cs = c->control_state;
+	struct control_line	*cl, *cl1;
+
+	TAILQ_FOREACH_SAFE(cl, &cs->deferred, entry, cl1) {
+		TAILQ_REMOVE(&cs->deferred, cl, entry);
+		control_write_line(c, cl->line);
+		free(cl);
+	}
+}
+
+/*
+ * Write a line of command output or error text. This is a sink for arbitrary
+ * user-controlled text (command output, capture-pane, error messages), so it
+ * must never try to interpret the content: guard tracking is done only in
+ * control_write_guard.
+ */
+void
+control_write(struct client *c, const char *fmt, ...)
+{
+	struct control_state	*cs = c->control_state;
+	char			*line;
+	va_list			 ap;
+
+	if (cs == NULL)
+		return;
+
+	va_start(ap, fmt);
+	xvasprintf(&line, fmt, ap);
 	va_end(ap);
+
+	control_write_line(c, line);
+}
+
+/*
+ * Write a %begin, %end or %error guard around a command's output. This is the
+ * only place guard lines are produced, so the block depth is maintained here;
+ * when the outermost block closes any deferred notifications are flushed after
+ * it. "guard" is always one of the fixed strings from cmdq_guard, never user
+ * text.
+ */
+void
+control_write_guard(struct client *c, const char *guard, long t, u_int number,
+    int flags)
+{
+	struct control_state	*cs = c->control_state;
+	char			*line;
+
+	if (cs == NULL)
+		return;
+
+	if (strcmp(guard, "begin") == 0)
+		cs->guard_depth++;
+
+	xasprintf(&line, "%%%s %ld %u %d", guard, t, number, flags);
+	control_write_line(c, line);
+
+	if (strcmp(guard, "begin") != 0 && cs->guard_depth > 0 &&
+	    --cs->guard_depth == 0)
+		control_flush_deferred(c);
+}
+
+/*
+ * Write a notification line. Notifications must never appear inside a command's
+ * %begin/%end guard block, so if one is open the line is deferred until it
+ * closes.
+ */
+void
+control_notify_write(struct client *c, const char *fmt, ...)
+{
+	struct control_state	*cs = c->control_state;
+	struct control_line	*cl;
+	va_list			 ap;
+	char			*line;
+
+	if (cs == NULL)
+		return;
+
+	va_start(ap, fmt);
+	xvasprintf(&line, fmt, ap);
+	va_end(ap);
+
+	if (cs->guard_depth == 0) {
+		control_write_line(c, line);
+		return;
+	}
+
+	log_debug("%s: %s: deferring notification: %s", __func__, c->name,
+	    line);
+	cl = xcalloc(1, sizeof *cl);
+	cl->line = line;
+	TAILQ_INSERT_TAIL(&cs->deferred, cl, entry);
 }
 
 /* Check age for this pane. */
@@ -438,7 +603,7 @@ control_check_age(struct client *c, struct window_pane *wp,
 			return (0);
 		cp->flags |= CONTROL_PANE_PAUSED;
 		control_discard_pane(c, cp);
-		control_write(c, "%%pause %%%u", wp->id);
+		control_notify_write(c, "%%pause %%%u", wp->id);
 	} else {
 		if (age < CONTROL_MAXIMUM_AGE)
 			return (0);
@@ -805,14 +970,17 @@ control_sub_change(struct monitor_change *change, __unused void *data)
 
 	if (wp != NULL) {
 		w = wp->window;
-		control_write(c, "%%subscription-changed %s $%u @%u %u %%%u : %s",
+		control_notify_write(c,
+		    "%%subscription-changed %s $%u @%u %u %%%u : %s",
 		    change->name, s->id, w->id, wl->idx, wp->id, change->value);
 	} else if (wl != NULL) {
 		w = wl->window;
-		control_write(c, "%%subscription-changed %s $%u @%u %u - : %s",
+		control_notify_write(c,
+		    "%%subscription-changed %s $%u @%u %u - : %s",
 		    change->name, s->id, w->id, wl->idx, change->value);
 	} else {
-		control_write(c, "%%subscription-changed %s $%u - - - : %s",
+		control_notify_write(c,
+		    "%%subscription-changed %s $%u - - - : %s",
 		    change->name, s->id, change->value);
 	}
 }
@@ -835,6 +1003,7 @@ control_start(struct client *c)
 	RB_INIT(&cs->windows);
 	TAILQ_INIT(&cs->pending_list);
 	TAILQ_INIT(&cs->all_blocks);
+	TAILQ_INIT(&cs->deferred);
 	cs->subs = monitor_create_client(c, control_sub_change, NULL);
 
 	cs->read_event = bufferevent_new(c->fd, control_read_callback,
@@ -878,6 +1047,20 @@ control_discard(struct client *c)
 	bufferevent_disable(cs->read_event, EV_READ);
 }
 
+/* Discard all tmux-owned queued control blocks and stop writing. */
+void
+control_discard_all(struct client *c)
+{
+	struct control_state	*cs = c->control_state;
+	struct control_block	*cb, *cb1;
+
+	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);
+}
+
 /* Stop control mode. */
 void
 control_stop(struct client *c)
@@ -885,12 +1068,19 @@ control_stop(struct client *c)
 	struct control_state	*cs = c->control_state;
 	struct control_block	*cb, *cb1;
 	struct control_window	*cw, *cw1;
+	struct control_line	*cl, *cl1;
 
 	if (cs == NULL)
 		return;
 
 	monitor_destroy(cs->subs);
 
+	TAILQ_FOREACH_SAFE(cl, &cs->deferred, entry, cl1) {
+		TAILQ_REMOVE(&cs->deferred, cl, entry);
+		free(cl->line);
+		free(cl);
+	}
+
 	if (~c->flags & CLIENT_CONTROLCONTROL)
 		bufferevent_free(cs->write_event);
 	bufferevent_free(cs->read_event);

file.c

@@ -1,4 +1,4 @@
-/* $OpenBSD: file.c,v 1.21 2026/07/26 15:08:15 nicm Exp $ */
+/* $OpenBSD: file.c,v 1.22 2026/08/17 07:56:56 nicm Exp $ */
 
 /*
  * Copyright (c) 2019 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -502,6 +502,7 @@ file_push(struct client_file *cf)
 	} else if (cf->stream > 2) {
 		close.stream = cf->stream;
 		proc_send(cf->peer, MSG_WRITE_CLOSE, -1, &close, sizeof close);
+		if (cf->c == NULL || (~cf->c->flags & CLIENT_WRITE_ACK))
 			file_fire_done(cf);
 	}
 	free(msg);
@@ -527,14 +528,48 @@ file_write_left(struct client_files *files)
 	return (waiting != 0);
 }
 
+/* Finish writing a client file. */
+static void
+file_write_finished(struct client_file *cf)
+{
+	struct msg_write_done	 msg;
+
+	if (cf->event != NULL) {
+		bufferevent_free(cf->event);
+		cf->event = NULL;
+	}
+	if (cf->fd != -1) {
+		if (close(cf->fd) != 0 && cf->error == 0)
+			cf->error = errno;
+		cf->fd = -1;
+	}
+
+	msg.stream = cf->stream;
+	msg.error = cf->error;
+	proc_send(cf->peer, MSG_WRITE_DONE, -1, &msg, sizeof msg);
+
+	if (cf->cb != NULL)
+		cf->cb(NULL, NULL, 0, -1, NULL, cf->data);
+	file_free(cf);
+}
+
 /* Client file write error callback. */
 static void
-file_write_error_callback(__unused struct bufferevent *bev, __unused short what,
+file_write_error_callback(__unused struct bufferevent *bev, short what,
     void *arg)
 {
 	struct client_file	*cf = arg;
+	int			 error;
+
+	if (what & EVBUFFER_ERROR)
+		error = errno;
+	else
+		error = EIO;
+	if (error == 0)
+		error = EIO;
 
 	log_debug("write error file %d", cf->stream);
+	cf->error = error;
 
 	bufferevent_free(cf->event);
 	cf->event = NULL;
@@ -542,7 +577,9 @@ file_write_error_callback(__unused struct bufferevent *bev, __unused short what,
 	close(cf->fd);
 	cf->fd = -1;
 
-	if (cf->cb != NULL)
+	if (cf->closed)
+		file_write_finished(cf);
+	else if (cf->cb != NULL)
 		cf->cb(NULL, NULL, 0, -1, NULL, cf->data);
 }
 
@@ -554,15 +591,10 @@ file_write_callback(__unused struct bufferevent *bev, void *arg)
 
 	log_debug("write check file %d", cf->stream);
 
-	if (cf->cb != NULL)
+	if (cf->closed && EVBUFFER_LENGTH(cf->event->output) == 0)
+		file_write_finished(cf);
+	else if (cf->cb != NULL)
 		cf->cb(NULL, NULL, 0, -1, NULL, cf->data);
-
-	if (cf->closed && EVBUFFER_LENGTH(cf->event->output) == 0) {
-		bufferevent_free(cf->event);
-		close(cf->fd);
-		RB_REMOVE(client_files, cf->tree, cf);
-		file_free(cf);
-	}
 }
 
 /* Handle a file write open message (client). */
@@ -663,14 +695,10 @@ file_write_close(struct client_files *files, struct imsg *imsg)
 	if ((cf = RB_FIND(client_files, files, &find)) == NULL)
 		fatalx("unknown stream number");
 	log_debug("close file %d", cf->stream);
+	cf->closed = 1;
 
 	if (cf->event == NULL || EVBUFFER_LENGTH(cf->event->output) == 0) {
-		if (cf->event != NULL)
+		file_write_finished(cf);
-			bufferevent_free(cf->event);
-		if (cf->fd != -1)
-			close(cf->fd);
-		RB_REMOVE(client_files, files, cf);
-		file_free(cf);
 	}
 }
 
@@ -829,6 +857,28 @@ file_write_ready(struct client_files *files, struct imsg *imsg)
 	return (0);
 }
 
+/* Handle a write done message (server). */
+int
+file_write_done(struct client_files *files, struct imsg *imsg)
+{
+	struct msg_write_done	*msg = imsg->data;
+	size_t			 msglen = imsg->hdr.len - IMSG_HEADER_SIZE;
+	struct client_file	 find, *cf;
+
+	if (msglen != sizeof *msg)
+		return (-1);
+	find.stream = msg->stream;
+	if ((cf = RB_FIND(client_files, files, &find)) == NULL)
+		return (0);
+	if (cf->c == NULL || (~cf->c->flags & CLIENT_WRITE_ACK))
+		return (0);
+
+	log_debug("file %d write done", cf->stream);
+	cf->error = msg->error;
+	file_fire_done(cf);
+	return (0);
+}
+
 /* Handle read data message (server). */
 int
 file_read_data(struct client_files *files, struct imsg *imsg)

format.c

@@ -1,4 +1,4 @@
-/* $OpenBSD: format.c,v 1.410 2026/07/29 20:43:20 nicm Exp $ */
+/* $OpenBSD: format.c,v 1.418 2026/09/20 08:19:31 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 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));
+		lcroot = w->saved_layout_root;
-	return (layout_dump(w, w->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)
@@ -2101,6 +2148,60 @@ format_cb_synchronized_output_flag(struct format_tree *ft)
 	return (NULL);
 }
 
+/* Callback for pane_private_modes. */
+static void *
+format_cb_pane_private_modes(struct format_tree *ft)
+{
+	static const struct {
+		int	mode;
+		int	number;
+	} table[] = {
+		{ MODE_KCURSOR,		1 },	/* DECCKM */
+		{ MODE_ORIGIN,		6 },	/* DECOM */
+		{ MODE_WRAP,		7 },	/* DECAWM */
+		{ MODE_CURSOR_BLINKING,	12 },	/* cursor blinking */
+		{ MODE_CURSOR,		25 },	/* DECTCEM */
+		{ MODE_MOUSE_STANDARD,	1000 },	/* mouse normal tracking */
+		{ MODE_MOUSE_BUTTON,	1002 },	/* mouse button tracking */
+		{ MODE_MOUSE_ALL,	1003 },	/* mouse any tracking */
+		{ MODE_FOCUSON,		1004 },	/* focus reporting */
+		{ MODE_MOUSE_UTF8,	1005 },	/* mouse: UTF-8 */
+		{ MODE_MOUSE_SGR,	1006 },	/* mouse: SGR */
+		{ MODE_BRACKETPASTE,	2004 },	/* bracketed paste */
+		{ MODE_SYNC,		2026 },	/* synchronized output */
+		{ MODE_THEME_UPDATES,	2031 },	/* theme update notifications */
+	};
+	int	 mode;
+	char	*value = NULL, *tmp;
+	u_int	 i;
+
+	if (ft->wp == NULL)
+		return (NULL);
+	mode = ft->wp->base.mode;
+
+	for (i = 0; i < nitems(table); i++) {
+		if (~mode & table[i].mode)
+			continue;
+		/*
+		 * Only report cursor blinking when set by the application, not
+		 * when it comes from the cursor-style option.
+		 */
+		if (table[i].mode == MODE_CURSOR_BLINKING &&
+		    (~mode & MODE_CURSOR_BLINKING_SET))
+			continue;
+		if (value == NULL)
+			xasprintf(&value, "%d", table[i].number);
+		else {
+			xasprintf(&tmp, "%s,%d", value, table[i].number);
+			free(value);
+			value = tmp;
+		}
+	}
+	if (value == NULL)
+		return (xstrdup(""));
+	return (value);
+}
+
 /* Callback for pane_active. */
 static void *
 format_cb_pane_active(struct format_tree *ft)
@@ -2222,6 +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)
@@ -2762,10 +2876,10 @@ format_cb_session_activity_flag(struct format_tree *ft)
 
 	if (ft->s != NULL) {
 		RB_FOREACH(wl, winlinks, &ft->s->windows) {
-			if (ft->wl->flags & WINLINK_ACTIVITY)
+			if (wl->flags & WINLINK_ACTIVITY)
 				return (xstrdup("1"));
-			return (xstrdup("0"));
 		}
+		return (xstrdup("0"));
 	}
 	return (NULL);
 }
@@ -2780,8 +2894,8 @@ format_cb_session_bell_flag(struct format_tree *ft)
 		RB_FOREACH(wl, winlinks, &ft->s->windows) {
 			if (wl->flags & WINLINK_BELL)
 				return (xstrdup("1"));
-			return (xstrdup("0"));
 		}
+		return (xstrdup("0"));
 	}
 	return (NULL);
 }
@@ -2794,10 +2908,10 @@ format_cb_session_silence_flag(struct format_tree *ft)
 
 	if (ft->s != NULL) {
 		RB_FOREACH(wl, winlinks, &ft->s->windows) {
-			if (ft->wl->flags & WINLINK_SILENCE)
+			if (wl->flags & WINLINK_SILENCE)
 				return (xstrdup("1"));
-			return (xstrdup("0"));
 		}
+		return (xstrdup("0"));
 	}
 	return (NULL);
 }
@@ -3609,12 +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
 	},
@@ -3795,6 +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
 	},
@@ -3813,6 +3939,9 @@ static const struct format_table_entry format_table[] = {
 	{ "pane_pipe_pid", FORMAT_TABLE_STRING,
 	  format_cb_pane_pipe_pid
 	},
+	{ "pane_private_modes", FORMAT_TABLE_STRING,
+	  format_cb_pane_private_modes
+	},
 	{ "pane_right", FORMAT_TABLE_STRING,
 	  format_cb_pane_right
 	},
@@ -4200,6 +4329,8 @@ format_log_debug_cb(const char *key, const char *value, void *arg)
 void
 format_log_debug(struct format_tree *ft, const char *prefix)
 {
+	if (log_get_level() == 0)
+		return;
 	format_each(ft, format_log_debug_cb, (void *)prefix);
 }
 
@@ -4328,7 +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;
 	}
@@ -5119,6 +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-view.c

@@ -1,4 +1,4 @@
-/* $OpenBSD: grid-view.c,v 1.38 2026/01/22 08:55:01 nicm Exp $ */
+/* $OpenBSD: grid-view.c,v 1.39 2026/08/03 12:58:53 nicm Exp $ */
 
 /*
  * Copyright (c) 2008 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -47,9 +47,9 @@ grid_view_set_cell(struct grid *gd, u_int px, u_int py,
 
 /* Set padding. */
 void
-grid_view_set_padding(struct grid *gd, u_int px, u_int py)
+grid_view_set_padding(struct grid *gd, u_int px, u_int py, int bg)
 {
-	grid_set_padding(gd, grid_view_x(gd, px), grid_view_y(gd, py));
+	grid_set_padding(gd, grid_view_x(gd, px), grid_view_y(gd, py), bg);
 }
 
 /* Set cells. */

grid.c

@@ -1,4 +1,4 @@
-/* $OpenBSD: grid.c,v 1.155 2026/07/29 17:42:56 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>
@@ -682,9 +682,13 @@ grid_set_cell(struct grid *gd, u_int px, u_int py, const struct grid_cell *gc)
 
 /* Set padding at position. */
 void
-grid_set_padding(struct grid *gd, u_int px, u_int py)
+grid_set_padding(struct grid *gd, u_int px, u_int py, int bg)
 {
-	grid_set_cell(gd, px, py, &grid_padding_cell);
+	struct grid_cell	gc;
+
+	memcpy(&gc, &grid_padding_cell, sizeof gc);
+	gc.bg = bg;
+	grid_set_cell(gd, px, py, &gc);
 }
 
 /* Set cells at position. */
@@ -1631,7 +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)
@@ -1645,7 +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 {
@@ -1707,21 +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) {
+		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 (tmp_gc.flags & GRID_FLAG_TAB)
+		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));
-		} else if (gc.flags & GRID_FLAG_TAB)
-			return (gc.data.width);
-	}
-	if (gc.flags & GRID_FLAG_PADDING)
 		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));
 }
 

image.c

@@ -84,6 +84,11 @@ image_fallback(char **ret, u_int sx, u_int sy)
 	char	*buf, *label;
 	u_int	 py, size, lsize;
 
+	if (sy == 0) {
+		*ret = xstrdup("");
+		return;
+	}
+
 	/* Allocate first line. */
 	lsize = xasprintf(&label, "SIXEL IMAGE (%ux%u)\r\n", sx, sy) + 1;
 	if (sx < lsize - 3)

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>
@@ -1049,6 +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;
@@ -1978,7 +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);

key-bindings.c

@@ -1,4 +1,4 @@
-/* $OpenBSD: key-bindings.c,v 1.190 2026/07/22 19:23:59 nicm Exp $ */
+/* $OpenBSD: key-bindings.c,v 1.193 2026/09/21 20:45:48 nicm Exp $ */
 
 /*
  * Copyright (c) 2007 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -421,6 +421,7 @@ key_bindings_init(void)
 		"bind -N 'Spread panes out evenly' E { select-layout -E }",
 		"bind -N 'Switch to the last client' L { switch-client -l }",
 		"bind -N 'Clear the marked pane' M { select-pane -M }",
+		"bind -N 'Change the pane title' T { command-prompt -I'#T' { select-pane -T '%%' } }",
 		"bind -N 'Enter copy mode' [ { copy-mode }",
 		"bind -N 'Paste the most recent paste buffer' ] { paste-buffer -p }",
 		"bind -N 'Create a new window' c { new-window }",
@@ -522,7 +523,7 @@ key_bindings_init(void)
 		"bind -n TripleClick1Pane { select-pane -t=; if -F '#{||:#{pane_in_mode},#{mouse_any_flag}}' { send -M } { copy-mode -H; send -X select-line; run -d0.3; send -X copy-pipe-and-cancel } }",
 
 		/* Mouse button 1 on border. */
-		"bind -n MouseDown1Border { select-pane -M }",
+		"bind -n MouseDown1Border { select-pane -t= }",
 
 		/* Mouse button 1 drag on border. */
 		"bind -n MouseDrag1Border { resize-pane -M }",
@@ -595,7 +596,7 @@ key_bindings_init(void)
 		"bind -Tcopy-mode g { command-prompt -P -p'(goto line)' { send -X goto-line -- '%%' } }",
 		"bind -Tcopy-mode n { send -X search-again }",
 		"bind -Tcopy-mode q { send -X cancel }",
-		"bind -Tcopy-mode r { send -X refresh-toggle }",
+		"bind -Tcopy-mode r { send -X refresh-now }",
 		"bind -Tcopy-mode t { command-prompt -P -1p'(jump to forward)' { send -X jump-to-forward -- '%%' } }",
 		"bind -Tcopy-mode Home { send -X start-of-line }",
 		"bind -Tcopy-mode End { send -X end-of-line }",
@@ -705,7 +706,7 @@ key_bindings_init(void)
 		"bind -Tcopy-mode-vi n { send -X search-again }",
 		"bind -Tcopy-mode-vi o { send -X other-end }",
 		"bind -Tcopy-mode-vi q { send -X cancel }",
-		"bind -Tcopy-mode-vi r { send -X refresh-toggle }",
+		"bind -Tcopy-mode-vi r { send -X refresh-now }",
 		"bind -Tcopy-mode-vi t { command-prompt -P -1p'(jump to forward)' { send -X jump-to-forward -- '%%' } }",
 		"bind -Tcopy-mode-vi v { send -X rectangle-toggle }",
 		"bind -Tcopy-mode-vi w { send -X next-word }",

layout.c

@@ -1,4 +1,4 @@
-/* $OpenBSD: layout.c,v 1.96 2026/07/15 13:02:33 nicm Exp $ */
+/* $OpenBSD: layout.c,v 1.101 2026/09/20 08:42:46 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 this is the last tiled cell, move back one. */
-	if (lc == TAILQ_LAST(&lcparent->cells, layout_cells)) {
+	if (layout_cell_is_last_tiled(lc)) {
-		do
+		lc = layout_cell_get_neighbour_dir(lc, 0);
-			lc = TAILQ_PREV(lc, layout_cells, entry);
+		if (lc == NULL)
-		while (lc->flags & LAYOUT_CELL_FLOATING);
+			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)
+	if (flags & SPAWN_FLOATOVERZOOM)
-		window_push_modal_zoom(w);
+		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);
@@ -1690,7 +1728,7 @@ layout_floating_args_parse(struct cmdq_item *item, struct args *args,
     enum pane_lines lines, struct window *w, struct layout_geometry *lg,
     char **cause)
 {
-	int	 sx, sy, ox, oy;
+	int	 sx, sy, ox, oy, pad;
 	char	*error = NULL;
 
 	sx = lg->sx == UINT_MAX ? w->sx / 2 : lg->sx;
@@ -1739,12 +1777,20 @@ layout_floating_args_parse(struct cmdq_item *item, struct args *args,
 		}
 	}
 
+	if (!window_has_floating_panes(w)) {
+		w->last_new_pane_x = 0;
+		w->last_new_pane_y = 0;
+	}
 	if (ox == INT_MAX) {
 		if (w->last_new_pane_x == 0)
 			ox = 4;
 		else {
+			if (lines != PANE_LINES_NONE)
+				pad = 1;
+			else
+				pad = 0;
 			ox = w->last_new_pane_x + 4;
-			if (w->last_new_pane_x > w->sx)
+			if (ox + sx + pad > (int)w->sx)
 				ox = 4;
 		}
 		w->last_new_pane_x = ox;
@@ -1755,8 +1801,12 @@ layout_floating_args_parse(struct cmdq_item *item, struct args *args,
 		if (w->last_new_pane_y == 0)
 			oy = 2;
 		else {
+			if (lines != PANE_LINES_NONE)
+				pad = 1;
+			else
+				pad = 0;
 			oy = w->last_new_pane_y + 2;
-			if (w->last_new_pane_y > w->sy)
+			if (oy + sy + pad > (int)w->sy)
 				oy = 2;
 		}
 		w->last_new_pane_y = oy;

menu.c

@@ -1,4 +1,4 @@
-/* $OpenBSD: menu.c,v 1.69 2026/07/14 19:07:03 nicm Exp $ */
+/* $OpenBSD: menu.c,v 1.70 2026/08/17 07:33:55 nicm Exp $ */
 
 /*
  * Copyright (c) 2019 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -337,6 +337,7 @@ menu_key(struct client *c, struct menu_data *md, struct key_event *event)
 	struct cmdq_state		*state;
 	enum cmd_parse_status		 status;
 	char				*error;
+	key_code			 key;
 
 	if (KEYC_IS_MOUSE(event->key)) {
 		/*
@@ -387,7 +388,8 @@ menu_key(struct client *c, struct menu_data *md, struct key_event *event)
 		name = menu->items[i].name;
 		if (name == NULL || *name == '-')
 			continue;
-		if ((event->key & ~KEYC_MASK_FLAGS) == menu->items[i].key) {
+		key = (event->key & ~KEYC_MASK_FLAGS);
+		if (key == (menu->items[i].key & ~KEYC_MASK_FLAGS)) {
 			md->choice = i;
 			goto chosen;
 		}

mode-tree.c

@@ -1,4 +1,4 @@
-/* $OpenBSD: mode-tree.c,v 1.100 2026/07/14 19:07:03 nicm Exp $ */
+/* $OpenBSD: mode-tree.c,v 1.101 2026/08/05 07:50:21 nicm Exp $ */
 
 /*
  * Copyright (c) 2017 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -47,7 +47,7 @@ enum mode_tree_preview {
 	"#[acs]x" MODE_TREE_PREFIX_STYLE "   }," \
 	"#{mode_tree_repeat}}" \
 	"#{?mode_tree_branch," \
-	"#[acs]#{?mode_tree_last,mq,tq}" MODE_TREE_PREFIX_STYLE "> ,}" \
+	"#[acs]#{?mode_tree_last,mq,tq}+" MODE_TREE_PREFIX_STYLE " ,}" \
 	"#{?mode_tree_has_children," \
 	"#{?mode_tree_expanded,#[fg=themered]-" MODE_TREE_PREFIX_STYLE " ," \
 	"#[fg=themegreen]+" MODE_TREE_PREFIX_STYLE " }," \

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 1.245 2026/09/10 11:02:18 nicm Exp $ */
 
 /*
  * Copyright (c) 2011 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -91,7 +91,7 @@ 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 +305,16 @@ 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,
@@ -1240,7 +1250,8 @@ 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. */
@@ -1687,7 +1698,8 @@ 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>
@@ -79,6 +79,7 @@ popup_free(struct popup_data *pd)
 
 	if (pd->job != NULL)
 		job_free(pd->job);
+	if (pd->ictx != NULL)
 		input_free(pd->ictx);
 
 	free(pd->r.ranges);

proc.c

@@ -1,4 +1,4 @@
-/* $OpenBSD: proc.c,v 1.31 2026/06/08 21:38:19 nicm Exp $ */
+/* $OpenBSD: proc.c,v 1.32 2026/08/04 13:16:03 claudio Exp $ */
 
 /*
  * Copyright (c) 2015 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -79,7 +79,7 @@ static void
 proc_event_cb(__unused int fd, short events, void *arg)
 {
 	struct tmuxpeer	*peer = arg;
-	ssize_t		 n;
+	int		 n;
 	struct imsg	 imsg;
 
 	if (!(peer->flags & PEER_BAD) && (events & EV_READ)) {
@@ -88,7 +88,7 @@ proc_event_cb(__unused int fd, short events, void *arg)
 			return;
 		}
 		for (;;) {
-			if ((n = imsg_get(&peer->ibuf, &imsg)) == -1) {
+			if ((n = imsgbuf_get(&peer->ibuf, &imsg)) == -1) {
 				peer->dispatchcb(NULL, peer->arg);
 				return;
 			}

prompt.c

@@ -1,4 +1,4 @@
-/* $OpenBSD: prompt.c,v 1.5 2026/07/13 10:29:17 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>
@@ -1334,7 +1334,7 @@ process_key:
 		if (pr->index != size) {
 			memmove(pr->buffer + pr->index,
 			    pr->buffer + pr->index + 1,
-			    (size + 1 - pr->index) *
+			    (size - pr->index) *
 			    sizeof *pr->buffer);
 			goto changed;
 		}
@@ -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/Makefile

@@ -1,33 +1,17 @@
 TESTS!= echo *.sh
 LOGDIR=logs
 
-.PHONY: all
+.PHONY: all prepare $(TESTS)
-.NOTPARALLEL: all
 
-all:
+all: prepare $(TESTS)
-	@mkdir -p "$(LOGDIR)"; \
+	@failed=0; failures=; \
-	rm -f "$(LOGDIR)"/*.log; \
-	failed=0; failures=; \
 	for test in $(TESTS); do \
 		base=$${test##*/}; \
 		log="$(LOGDIR)/$${base%.sh}.log"; \
-		rm -f "$$log"; \
+		if [ -f "$$log" ]; then \
-		printf '%-40s ' "$$test"; \
-		start=$$(date +%s); \
-		env -i LC_CTYPE=C.UTF-8 MallocNanoZone=0 \
-		    sh -x "$$test" >"$$log" 2>&1; \
-		if [ $$? -eq 0 ]; then \
-			end=$$(date +%s); \
-			rm -f "$$log"; \
-			echo "PASS ($$((end - start))s)"; \
-		else \
-			end=$$(date +%s); \
-			echo "FAIL ($$((end - start))s)"; \
-			echo " log: $$log"; \
 			failed=1; \
 			failures="$$failures $$test"; \
 		fi; \
-		sleep 1; \
 	done; \
 	if [ "$$failed" -ne 0 ]; then \
 		echo; \
@@ -39,3 +23,22 @@ all:
 		rmdir "$(LOGDIR)" 2>/dev/null || true; \
 	fi; \
 	exit $$failed
+
+prepare:
+	@mkdir -p "$(LOGDIR)"
+	@rm -f "$(LOGDIR)"/*.log
+
+$(TESTS): prepare
+	@base="$@"; base=$${base##*/}; \
+	log="$(LOGDIR)/$${base%.sh}.log"; \
+	start=$$(date +%s); \
+	if env -i LC_CTYPE=C.UTF-8 MallocNanoZone=0 \
+	    sh -x "$@" >"$$log" 2>&1; then \
+		end=$$(date +%s); \
+		rm -f "$$log"; \
+		printf '%-40s PASS (%ss)\n' "$@" "$$((end - start))"; \
+	else \
+		end=$$(date +%s); \
+		printf '%-40s FAIL (%ss)\n log: %s\n' \
+		    "$@" "$$((end - start))" "$$log"; \
+	fi

regress/alerts.sh

@@ -2,8 +2,9 @@
 
 # monitor-activity, monitor-bell and monitor-silence: both the
 # alert-activity, alert-bell and alert-silence hooks and the winlink alert
-# flags (window_activity_flag, window_bell_flag, window_silence_flag and
+# flags (window_activity_flag, window_bell_flag, window_silence_flag,
-# the #, !, ~ characters in window_flags). The sessions are detached so
+# their session equivalents and the #, !, ~ characters in window_flags).
+# The sessions are detached so
 # alert flags are set even on the current window; the *-action options
 # still decide whether the hooks fire. Panes run cat: activity is
 # generated by the tty echo of send-keys and a bell by sending a BEL and
@@ -111,6 +112,24 @@ flags_have()
 	esac
 }
 
+assert_session_flag()
+{
+	flag="#{session_${1}_flag}"
+	expected=$2
+
+	# Only mon exists here. Check both window contexts and list-sessions.
+	for target in mon:w0 "mon:$3"; do
+		value=$($TMUX display -pt "$target" "$flag") ||
+			fail "display $flag failed"
+		[ "$value" = "$expected" ] ||
+			fail "expected $flag for $target to be '$expected' but got '$value'"
+	done
+	value=$($TMUX list-sessions -F "$flag") ||
+		fail "list-sessions $flag failed"
+	[ "$value" = "$expected" ] ||
+		fail "expected list-sessions $flag to be '$expected' but got '$value'"
+}
+
 flags_lack()
 {
 	target=$1
@@ -150,10 +169,12 @@ $TMUX set-hook -g alert-silence \
 # alert-bell and sets the bell flag, shown as ! in window_flags.
 $TMUX neww -d -t mon: -n bellw cat || fail "new-window bellw failed"
 assert_fmt_unchanged mon:bellw '#{window_bell_flag}' 0
+assert_session_flag bell 0 bellw
 flags_lack mon:bellw '!'
 bell mon:bellw
 wait_for @log '|alert-bell:mon:bellw'
 wait_for_fmt mon:bellw '#{window_bell_flag}' 1
+assert_session_flag bell 1 bellw
 flags_have mon:bellw '!'
 
 # Bells are not deduplicated: a second bell fires the hook again even
@@ -164,6 +185,7 @@ wait_for @log '|alert-bell:mon:bellw|alert-bell:mon:bellw'
 # Selecting the window clears the alert flags.
 $TMUX selectw -t mon:bellw || fail "select-window bellw failed"
 wait_for_fmt mon:bellw '#{window_bell_flag}' 0
+assert_session_flag bell 0 bellw
 flags_lack mon:bellw '!'
 $TMUX selectw -t mon:w0 || fail "select-window w0 failed"
 
@@ -173,6 +195,7 @@ $TMUX set -g @log '' || fail "reset @log failed"
 bell mon:w0
 wait_for @log '|alert-bell:mon:w0'
 wait_for_fmt mon:w0 '#{window_bell_flag}' 1
+assert_session_flag bell 1 bellw
 $TMUX selectw -t mon:bellw || fail "select-window bellw failed"
 $TMUX selectw -t mon:w0 || fail "select-window w0 failed"
 wait_for_fmt mon:w0 '#{window_bell_flag}' 0
@@ -199,6 +222,7 @@ $TMUX neww -d -t mon: -n actw cat || fail "new-window actw failed"
 $TMUX set -g @log '' || fail "reset @log failed"
 activity mon:actw
 assert_fmt_unchanged mon:actw '#{window_activity_flag}' 0
+assert_session_flag activity 0 actw
 assert_unchanged @log ''
 
 # With monitor-activity on, output fires alert-activity and sets the
@@ -208,6 +232,7 @@ $TMUX set -wt mon:actw monitor-activity on ||
 activity mon:actw
 wait_for @log '|alert-activity:mon:actw'
 wait_for_fmt mon:actw '#{window_activity_flag}' 1
+assert_session_flag activity 1 actw
 flags_have mon:actw '#'
 
 # While the flag is set further activity does not fire the hook again.
@@ -234,6 +259,7 @@ exec 3>"$OUT/fifo"
 wait_for_fmt mon: '#{session_attached}' 1
 $TMUX selectw -t mon:actw || fail "select-window actw failed"
 wait_for_fmt mon:actw '#{window_activity_flag}' 0
+assert_session_flag activity 0 actw
 flags_lack mon:actw '#'
 $TMUX selectw -t mon:w0 || fail "select-window w0 failed"
 exec 3>&-
@@ -250,6 +276,7 @@ $TMUX set -wt mon:w0 monitor-activity on ||
 $TMUX set -g @log '' || fail "reset @log failed"
 activity mon:w0
 wait_for_fmt mon:w0 '#{window_activity_flag}' 1
+assert_session_flag activity 1 actw
 assert_unchanged @log ''
 $TMUX set -wut mon:w0 monitor-activity ||
 	fail "unset monitor-activity w0 failed"
@@ -273,16 +300,19 @@ $TMUX selectw -t mon:w0 || fail "select-window w0 failed"
 # running.
 $TMUX neww -d -t mon: -n silw cat || fail "new-window silw failed"
 assert_fmt_unchanged mon:silw '#{window_silence_flag}' 0
+assert_session_flag silence 0 silw
 $TMUX set -g @log '' || fail "reset @log failed"
 $TMUX set -wt mon:silw monitor-silence 1 || fail "set monitor-silence failed"
 wait_for @log '|alert-silence:mon:silw'
 wait_for_fmt mon:silw '#{window_silence_flag}' 1
+assert_session_flag silence 1 silw
 flags_have mon:silw '~'
 assert_unchanged @log '|alert-silence:mon:silw'
 $TMUX set -wt mon:silw monitor-silence 0 ||
 	fail "reset monitor-silence failed"
 $TMUX selectw -t mon:silw || fail "select-window silw failed"
 wait_for_fmt mon:silw '#{window_silence_flag}' 0
+assert_session_flag silence 0 silw
 flags_lack mon:silw '~'
 $TMUX selectw -t mon:w0 || fail "select-window w0 failed"
 

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/codepoint-widths.sh

@@ -0,0 +1,53 @@
+#!/bin/sh
+
+# Width cache ranges must include their endpoint without overflowing wchar_t.
+
+PATH=/bin:/usr/bin
+TERM=screen
+
+[ -z "$TEST_TMUX" ] && TEST_TMUX=$(readlink -f ../tmux)
+TMUX="$TEST_TMUX -LtestA$$ -f/dev/null"
+SERVER=
+WATCHDOG=
+
+cleanup()
+{
+	if [ -n "$WATCHDOG" ]; then
+		kill "$WATCHDOG" 2>/dev/null
+		wait "$WATCHDOG" 2>/dev/null
+	fi
+	[ -n "$SERVER" ] && kill -9 "$SERVER" 2>/dev/null
+}
+trap cleanup 0
+trap 'exit 1' 1 2 15
+
+$TMUX new-session -d 'exec sleep 60' || exit 1
+SERVER=$($TMUX display-message -p '#{pid}') || exit 1
+
+# kill-server cannot stop a server stuck rebuilding the width cache.
+(
+	sleep 5
+	kill -9 "$SERVER" 2>/dev/null
+) &
+WATCHDOG=$!
+
+$TMUX set -g codepoint-widths 'U+1F600=2' || exit 1
+
+# Cover both signed and unsigned 32-bit wchar_t. Values above WCHAR_MAX
+# are ignored by the parser on platforms where they cannot be represented.
+for value in U+7FFFFFFF=1 U+7FFFFFFE-U+7FFFFFFF=2 \
+    U+FFFFFFFF=1 U+FFFFFFFE-U+FFFFFFFF=2; do
+	$TMUX set -g codepoint-widths "$value" || exit 1
+	[ "$($TMUX display-message -p alive)" = alive ] || exit 1
+done
+
+# Check that an ordinary range still includes both endpoints and stops there.
+$TMUX set -g codepoint-widths 'U+03B1-U+03B3=2' || exit 1
+$TMUX set -g @text 'αβγδ' || exit 1
+[ "$($TMUX display-message -p '#{w:@text}')" = 7 ] || exit 1
+$TMUX set -gu codepoint-widths || exit 1
+[ "$($TMUX display-message -p '#{w:@text}')" = 4 ] || exit 1
+
+$TMUX kill-server || exit 1
+SERVER=
+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-exit-stalled.sh

@@ -0,0 +1,77 @@
+#!/bin/sh
+
+# A control client whose terminal has stopped accepting output (for example
+# its ssh connection or terminal emulator died) never drains the output that
+# server_client_check_exit waits on before sending MSG_EXIT, and may then
+# never close its socket either. This must not prevent the server from
+# exiting: after kill-server the server previously stayed alive forever with
+# server_exit set, closing every new connection immediately, so every new
+# client failed with "server exited unexpectedly" until the server was killed
+# by hand. The server now bounds the exit handshake: it discards output it
+# can never deliver and drops the client if it still does not close.
+#
+# The stalled terminal is simulated by a fifo whose read end is held open but
+# never read.
+
+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
+
+# A detached session whose pane floods printable output forever.
+$TMUX -f/dev/null new -d -x 80 -y 24 -s rt 'cat /dev/zero | tr "\000" x' || exit 1
+SERVER=$($TMUX display -pt rt '#{pid}')
+
+# Attach a control client with output down the fifo; stdin held open by sleep
+# so it stays attached. The fifo fills and is never read, so a backlog forms
+# in the server that can never be delivered.
+( sleep 60 ) | $TMUX -f/dev/null -C attach -t rt >"$FIFO" 2>&1 &
+exec 8<"$FIFO"
+
+n=0
+while [ $n -lt 50 ]; do
+	$TMUX lsc -F '#{client_name}' 2>/dev/null | grep -q . && break
+	sleep 0.1
+	n=$((n + 1))
+done
+$TMUX lsc -F '#{client_name}' 2>/dev/null | grep -q . ||
+	{ echo "control client did not attach"; exit 1; }
+
+# Let the pane flood fill the fifo so the client's output is stuck.
+sleep 2
+
+# Ask the server to exit. This sets CLIENT_EXIT on the stalled client, whose
+# output can never drain.
+$TMUX kill-server 2>/dev/null
+
+# The server must exit within the exit timeout (10 seconds) plus slack,
+# rather than staying in limbo forever rejecting new clients.
+n=0
+while [ $n -lt 100 ]; do
+	if ! kill -0 "$SERVER" 2>/dev/null; then
+		SERVER=
+		exit 0
+	fi
+	sleep 0.2
+	n=$((n + 1))
+done
+
+echo "server did not exit after kill-server; new clients see:"
+$TMUX ls 2>&1
+exit 1

regress/control-client-exit.sh

@@ -19,7 +19,7 @@ PATH=/bin:/usr/bin
 TERM=screen
 
 [ -z "$TEST_TMUX" ] && TEST_TMUX=$(readlink -f ../tmux)
-TMUX="$TEST_TMUX -Ltest"
+TMUX="$TEST_TMUX -Ltest$$"
 $TMUX kill-server 2>/dev/null
 
 DIR=$(mktemp -d)

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
+# Use a control client to request legacy layouts, keeping only pane lines
-cat <<EOF|cmp -s $TMP - || exit 1
+# from the control protocol output.
+$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/control-client-wait-exit.sh

@@ -10,7 +10,7 @@ PATH=/bin:/usr/bin
 TERM=screen
 
 [ -z "$TEST_TMUX" ] && TEST_TMUX=$(readlink -f ../tmux)
-TMUX="$TEST_TMUX -Ltest"
+TMUX="$TEST_TMUX -Ltest$$"
 $TMUX kill-server 2>/dev/null
 
 FIFO=$(mktemp -u)

regress/control-notify-guard.sh

@@ -0,0 +1,158 @@
+#!/bin/sh
+
+PATH=/bin:/usr/bin
+TERM=screen
+LC_ALL=C.UTF-8
+LANG=C.UTF-8
+export TERM LC_ALL LANG
+
+[ -z "$TEST_TMUX" ] && TEST_TMUX=$(readlink -f ../tmux)
+TMUX="$TEST_TMUX -LtestA$$ -f/dev/null"
+
+TMPDIR=$(mktemp -d)
+IN="$TMPDIR/in"
+OUT="$TMPDIR/out"
+BADCFG="$TMPDIR/bad.conf"
+PID=
+
+cleanup()
+{
+	exec 3>&- 2>/dev/null
+	[ -n "$PID" ] && kill "$PID" 2>/dev/null
+	$TMUX kill-server 2>/dev/null
+	rm -rf "$TMPDIR"
+}
+trap cleanup EXIT
+
+fail()
+{
+	echo "$1" >&2
+	[ -s "$OUT" ] && cat "$OUT" >&2
+	exit 1
+}
+
+wait_for()
+{
+	pattern=$1
+	timeout=${2:-60}
+	i=0
+
+	while [ "$i" -lt "$timeout" ]; do
+		grep -F -- "$pattern" "$OUT" >/dev/null 2>&1 && return 0
+		sleep 0.1
+		i=$((i + 1))
+	done
+	fail "missing: $pattern"
+}
+
+wait_for_count()
+{
+	pattern=$1
+	expected=$2
+	timeout=${3:-60}
+	i=0
+
+	while [ "$i" -lt "$timeout" ]; do
+		count=$(grep -F -c -- "$pattern" "$OUT" 2>/dev/null)
+		[ "$count" -ge "$expected" ] && return 0
+		sleep 0.1
+		i=$((i + 1))
+	done
+	fail "missing count $expected for: $pattern"
+}
+
+send()
+{
+	printf '%s\n' "$1" >&3 || fail "failed to send: $1"
+}
+
+# A notification is a standalone protocol message. It must never be part of
+# the response between the real %begin and matching %end or %error for a
+# command. Ignore guard-looking command output while a real guard is open.
+check_guards()
+{
+	awk '
+	function notification(line) {
+		return line ~ /^%(sessions-changed|session-changed |unlinked-window-add )/ ||
+		    line ~ /^%(pause |continue |config-error )/
+	}
+	!open && $0 ~ /^%begin [0-9]+ [0-9]+ [0-9]+$/ {
+		open = 1
+		time = $2
+		number = $3
+		flags = $4
+		next
+	}
+	open && ($0 == "%end " time " " number " " flags ||
+	    $0 == "%error " time " " number " " flags) {
+		open = 0
+		next
+	}
+	notification($0) {
+		seen[$1]++
+		if (open) {
+			print "notification inside guard: " $0 > "/dev/stderr"
+			bad = 1
+		}
+	}
+	END {
+		if (open) {
+			print "unterminated command guard" > "/dev/stderr"
+			bad = 1
+		}
+		if (seen["%sessions-changed"] < 2 ||
+		    seen["%session-changed"] < 1 ||
+		    seen["%unlinked-window-add"] < 2 ||
+		    seen["%pause"] < 1 || seen["%continue"] < 1 ||
+		    seen["%config-error"] < 1) {
+			print "missing expected notification" > "/dev/stderr"
+			bad = 1
+		}
+		exit bad
+	}' "$OUT" || fail "bad control protocol notification ordering"
+}
+
+$TMUX kill-server 2>/dev/null
+$TMUX new-session -d -s guard -x 80 -y 24 || exit 1
+pane=$($TMUX display-message -p -t guard:0.0 '#{pane_id}') || exit 1
+
+mkfifo "$IN" || exit 1
+: >"$OUT"
+$TMUX -C attach-session -t guard <"$IN" >"$OUT" 2>&1 &
+PID=$!
+exec 3>"$IN"
+
+# Attaching generates a session notification synchronously from inside the
+# attach command. It must follow the closing guard.
+wait_for '%session-changed '
+
+# Guard-looking output is arbitrary command output, not protocol state. Make
+# new-session both generate notifications and print an unmatched fake %begin;
+# it must not leave those notifications permanently deferred.
+send "set-option -g @fake-begin '%begin 1 2 3'"
+send "new-session -d -P -F '#{@fake-begin}' -s fake-begin"
+wait_for_count '%sessions-changed' 1
+
+# Likewise, fake %end output from a command that generates multiple
+# notifications must not flush them before the command actually ends.
+send "set-option -g @fake-end '%end 1 2 3'"
+send "new-session -d -P -F '#{@fake-end}' -s fake-end"
+wait_for_count '%sessions-changed' 2
+
+# Exercise notification paths outside control-notify.c.
+send "refresh-client -A '$pane:pause'"
+wait_for "%pause $pane"
+send "refresh-client -A '$pane:continue'"
+wait_for "%continue $pane"
+
+printf '%s\n' 'not-a-command' >"$BADCFG"
+send "source-file '$BADCFG'"
+wait_for '%config-error '
+
+# A final command guarantees all earlier command guards have completed before
+# the transcript is checked.
+send "display-message -p 'guard-check-done'"
+wait_for 'guard-check-done'
+check_guards
+
+exit 0

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-test-vi.sh

@@ -117,6 +117,7 @@ $TMUX send-keys -X copy-selection
 # Test that vi cursor movement does not stop on the padding cell of a wide
 # character at the end of a line.
 $TMUX kill-server 2>/dev/null
+sleep 1
 $TMUX new -d -x20 -y5 \
       "printf 'abc中\nxyz\n'; exec cat" || exit 1
 $TMUX set-window-option -g mode-keys vi

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/display-panes.sh

@@ -153,11 +153,13 @@ wait_format "$p0" '#{pane_in_mode}' '0'
 wait_option @picked "$p1"
 
 # Commands after display-panes run immediately while the mode remains.
+# Record the mode in the same command queue so client startup cannot race
+# the 500ms timeout.
 $TMUX set -g @after none || fail "set @after failed"
-$TMUX display-panes -Nd 500 -t "$p0" \; set -g @after fast ||
+$TMUX display-panes -Nd 500 -t "$p0" \; \
+    set -gF -t "$p0" @after '#{pane_mode}' ||
 	fail "display-panes immediate command failed"
-wait_option @after fast
+wait_option @after 'panes-mode'
-wait_format "$p0" '#{pane_mode}' 'panes-mode'
 wait_format "$p0" '#{pane_in_mode}' '0'
 
 # Existing zoom is restored on exit.

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/floating-pane-zoom.sh

@@ -0,0 +1,158 @@
+#!/bin/sh
+
+# Moving, resizing and reordering an over-zoom float must leave the tiled
+# pane zoomed, and the changes must survive an explicit unzoom.
+
+PATH=/bin:/usr/bin
+TERM=screen
+
+[ -z "$TEST_TMUX" ] && TEST_TMUX=$(readlink -f ../tmux)
+TMUX="$TEST_TMUX -LtestA$$ -f/dev/null"
+trap '$TMUX kill-server 2>/dev/null' 0
+trap 'exit 1' 1 2 15
+
+fail()
+{
+	echo "$*" >&2
+	exit 1
+}
+
+run()
+{
+	$TMUX "$@" || fail "failed: $*"
+}
+
+check()
+{
+	got=$(run display-message -p -t "$1" "$2") || exit 1
+	[ "$got" = "$3" ] || fail "$1 $2: got '$got', expected '$3'"
+}
+
+check_zoom()
+{
+	check "$base" '#{window_zoomed_flag}:#{pane_zoomed_flag}' '1:1'
+	check "$float" '#{pane_floating_flag}:#{pane_active}' "1:$active"
+	check "$base" '#{@unzoomed}' ''
+}
+
+run new-session -d -x 80 -y 24
+base=$(run display-message -p '#{pane_id}') || exit 1
+other=$(run split-window -dPF '#{pane_id}') || exit 1
+layout=$(run display-message -p '#{window_layout}') || exit 1
+run set-hook -g window-unzoomed 'set -g @unzoomed 1'
+
+# Cover creation before and after zoom, with both the float and the tiled
+# pane active. Modal panes use the same over-zoom flag.
+for mode in before after detached modal; do
+	if [ "$mode" != before ]; then
+		run resize-pane -Z -t "$base"
+	fi
+	case "$mode" in
+	detached) flags=-Ad; active=0 ;;
+	modal) flags=-O; active=1 ;;
+	*) flags=-A; active=1 ;;
+	esac
+	float=$(run new-pane "$flags" -PF '#{pane_id}' -t "$base" \
+	    -x 20 -y 8 -X 8 -Y 3 '') || exit 1
+	if [ "$mode" = before ]; then
+		run resize-pane -Z -t "$base"
+	fi
+	run set -gu @unzoomed
+	check_zoom
+
+	run move-pane -t "$float" -D
+	check "$float" '#{pane_top}' 5
+	check_zoom
+	run move-pane -t "$float" -U 2 -R 3 -L 1
+	check "$float" '#{pane_left}:#{pane_top}' '11:3'
+	check_zoom
+	run move-pane -t "$float" -X 25% -Y 25%
+	check "$float" '#{pane_left}:#{pane_top}' '21:7'
+	check_zoom
+	run move-pane -t "$float" -P bottom-right
+	check "$float" '#{pane_left}:#{pane_top}' '61:17'
+	check_zoom
+	run resize-pane -t "$float" -x 30 -y 10
+	check "$float" '#{pane_width}:#{pane_height}' '28:8'
+	check_zoom
+	run resize-pane -t "$float" -U 1 -L 2
+	check "$float" '#{pane_left}:#{pane_top}:#{pane_width}:#{pane_height}' \
+	    '59:16:30:9'
+	check_zoom
+	run move-pane -t "$float" -P centre
+	check "$float" '#{pane_left}:#{pane_top}' '25:7'
+	check_zoom
+
+	# Failed commands must not change zoom either.
+	for command in 'move-pane -D invalid' 'move-pane -P invalid' \
+	    'move-pane -z invalid' 'resize-pane -x invalid' \
+	    'resize-pane -D invalid'; do
+		$TMUX $command -t "$float" 2>/dev/null &&
+		    fail "unexpected success: $command"
+		check_zoom
+	done
+
+	run resize-pane -Z -t "$base"
+	check "$float" '#{pane_left}:#{pane_top}:#{pane_width}:#{pane_height}' \
+	    '25:7:30:9'
+	run kill-pane -t "$float"
+	check "$base" '#{window_layout}' "$layout"
+done
+
+# Put an ordinary (hidden while zoomed) float between two over-zoom floats
+# in the stacking order. Reordering must skip it when counting visible
+# positions, but keep all floats ahead of the tiled panes after unzoom.
+back=$(run new-pane -AdPF '#{pane_id}' -t "$base" '') || exit 1
+hidden=$(run new-pane -dPF '#{pane_id}' -t "$base" '') || exit 1
+float=$(run new-pane -AdPF '#{pane_id}' -t "$base" '') || exit 1
+active=0
+run resize-pane -Z -t "$base"
+run set -gu @unzoomed
+
+for position in backward back forward-loop; do
+	run move-pane -t "$float" -P front
+	run move-pane -t "$float" -P "$position"
+	check "$float" '#{pane_z}' 1
+	check "$back" '#{pane_z}' 0
+	check_zoom
+done
+for position in forward front backward-loop; do
+	run move-pane -t "$float" -P back
+	run move-pane -t "$float" -P "$position"
+	check "$float" '#{pane_z}' 0
+	check "$back" '#{pane_z}' 1
+	check_zoom
+done
+for z in 1 0 99; do
+	run move-pane -t "$float" -z "$z"
+	want=$z
+	[ "$z" = 99 ] && want=1
+	check "$float" '#{pane_z}' "$want"
+	check_zoom
+done
+run resize-pane -Z -t "$base"
+check "$float" '#{pane_z}' 2
+check "$base" '#{pane_z}' 4
+run kill-pane -t "$hidden"
+run kill-pane -t "$back"
+
+# Explicit zoom toggling and operations on tiled panes retain their
+# existing behaviour. The over-zoom flag alone does not make a pane a float:
+# zooming the float itself gives it a tiled cell until unzoom.
+run resize-pane -Z -t "$float"
+check "$float" '#{pane_zoomed_flag}:#{pane_floating_flag}' '1:0'
+run resize-pane -t "$float" -x 25
+check "$float" '#{window_zoomed_flag}:#{pane_floating_flag}:#{pane_width}' \
+    '0:1:23'
+run resize-pane -Z -t "$base"
+run resize-pane -t "$other" -D 1
+check "$base" '#{window_zoomed_flag}' 0
+
+# A hidden ordinary float must still be unzoomed before resizing it.
+hidden=$(run new-pane -dPF '#{pane_id}' -t "$base" '') || exit 1
+run resize-pane -Z -t "$base"
+run resize-pane -t "$hidden" -x 25
+check "$hidden" '#{window_zoomed_flag}:#{pane_floating_flag}:#{pane_width}' \
+    '0:1:23'
+
+exit 0

regress/format-fuzzy.sh

@@ -7,6 +7,8 @@ TERM=screen
 
 [ -z "$TEST_TMUX" ] && TEST_TMUX=$(readlink -f ../tmux)
 TMUX="$TEST_TMUX -LtestA$$ -f/dev/null"
+trap '$TMUX kill-server 2>/dev/null' 0
+trap 'exit 1' 1 2 15
 
 # test_format $format $expected_result
 test_format()

regress/format-modifiers.sh

@@ -18,6 +18,24 @@ export TZ LANG LC_ALL
 
 [ -z "$TEST_TMUX" ] && TEST_TMUX=$(readlink -f ../tmux)
 TMUX="$TEST_TMUX -LtestA$$ -f/dev/null"
+FIFO1="${TMPDIR:-/tmp}/fmt-l-$$-1"
+FIFO2="${TMPDIR:-/tmp}/fmt-l-$$-2"
+HOLD1=
+HOLD2=
+CC1=
+CC2=
+
+cleanup()
+{
+	for pid in $HOLD1 $HOLD2 $CC1 $CC2; do
+		kill "$pid" 2>/dev/null
+		wait "$pid" 2>/dev/null
+	done
+	$TMUX kill-server 2>/dev/null
+	rm -f "$FIFO1" "$FIFO2"
+}
+trap cleanup 0
+trap 'exit 1' 1 2 15
 
 ESC=$(printf '\033')
 
@@ -579,8 +597,6 @@ assert_alive "verbose loop expansion"
 
 # L loops over attached clients.  Attach two control-mode clients, each held
 # open by a background process keeping a FIFO's write end open.
-FIFO1="${TMPDIR:-/tmp}/fmt-l-$$-1"
-FIFO2="${TMPDIR:-/tmp}/fmt-l-$$-2"
 rm -f "$FIFO1" "$FIFO2"
 mkfifo "$FIFO1" "$FIFO2" || exit 1
 # Hold the write ends open so the control clients stay attached.
@@ -605,9 +621,9 @@ test_format "#{L/nr:x}" "xx"
 test_format "#{L/r:x}" "xx"
 # Now detach one and confirm the count drops to one.
 kill $HOLD2 2>/dev/null
+wait $HOLD2 2>/dev/null
+HOLD2=
 sleep 1
 test_format "#{L:x}" "x"
-kill $HOLD1 $CC1 $CC2 2>/dev/null
-rm -f "$FIFO1" "$FIFO2"
 
 exit 0

regress/format-strings.sh

@@ -7,6 +7,8 @@ TERM=screen
 
 [ -z "$TEST_TMUX" ] && TEST_TMUX=$(readlink -f ../tmux)
 TMUX="$TEST_TMUX -LtestA$$ -f/dev/null"
+trap '$TMUX kill-server 2>/dev/null' 0
+trap 'exit 1' 1 2 15
 
 # test_format $format $expected_result
 test_format()

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-lifecycle.sh

@@ -76,14 +76,14 @@ $TMUX set-hook -g session-closed \
 	fail "set-hook session-closed failed"
 
 # The only pane of the only window of a session exits: pane-exited, then
-# window-unlinked, then session-closed, each seeing the dead object in the
+# session-closed, then window-unlinked, each seeing the dead object in the
 # hook formats.
 pane=$($TMUX new -d -s doomed -n dwin -P -F '#{pane_id}' 'true') ||
 	fail "new-session doomed failed"
 wait_for @log \
-	"|pane-exited:$pane|window-unlinked:doomed:dwin|session-closed:doomed"
+	"|pane-exited:$pane|session-closed:doomed|window-unlinked:doomed:dwin"
 assert_unchanged @log \
-	"|pane-exited:$pane|window-unlinked:doomed:dwin|session-closed:doomed"
+	"|pane-exited:$pane|session-closed:doomed|window-unlinked:doomed:dwin"
 
 # The dead pane, window and session cannot be used as targets but the
 # server survives.
@@ -110,14 +110,14 @@ $TMUX set-hook -g pane-exited \
 	'set -gF @log "#{@log}|pane-exited:#{hook_pane}"' ||
 	fail "restore pane-exited hook failed"
 
-# kill-window on the last window: window-unlinked then session-closed but
+# kill-window on the last window: session-closed then window-unlinked but
 # no pane-exited for the panes in the killed window.
 $TMUX set -g @log '' || fail "reset @log failed"
 $TMUX new -d -s doomed2 -n dwin2 || fail "new-session doomed2 failed"
 $TMUX splitw -d -t doomed2:0 || fail "split-window doomed2 failed"
 $TMUX kill-window -t doomed2:0 || fail "kill-window failed"
-wait_for @log '|window-unlinked:doomed2:dwin2|session-closed:doomed2'
+wait_for @log '|session-closed:doomed2|window-unlinked:doomed2:dwin2'
-assert_unchanged @log '|window-unlinked:doomed2:dwin2|session-closed:doomed2'
+assert_unchanged @log '|session-closed:doomed2|window-unlinked:doomed2:dwin2'
 $TMUX has -t main || fail "server died after kill-window chain"
 
 # kill-session: session-closed fires first, then window-unlinked for its

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}"' ||
+$TMUX set-hook -g pane-exited \
+	'set -gF @x "#{hook}:#{hook_pane}:#{hook_exit_status}:#{hook_exit_success}"' ||
 	fail "set-hook pane-exited failed"
-pane=$($TMUX splitw -d -t main:0 -P -F '#{pane_id}' 'true') ||
+pane=$($TMUX splitw -d -t main:0 -P -F '#{pane_id}' \
-	fail "split-window true failed"
+	'trap "" HUP; exec </dev/null >/dev/null 2>&1; sleep 1; exit 42') ||
-wait_for @x "pane-exited:$pane"
+	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/if-shell-error.sh

@@ -12,7 +12,8 @@ $TMUX kill-server 2>/dev/null
 
 TMP=$(mktemp)
 OUT=$(mktemp)
-trap "rm -f $TMP $OUT" 0 1 15
+trap 'rm -f "$TMP" "$OUT"; $TMUX kill-server 2>/dev/null' 0
+trap 'exit 1' 1 2 15
 
 cat <<EOF >$TMP
 if 'true' 'wibble wobble'

regress/input-common.inc

@@ -4,6 +4,9 @@ TERM=screen
 [ -z "$TEST_TMUX" ] && TEST_TMUX=$(readlink -f ../tmux)
 TMUX="$TEST_TMUX -LtestA$$ -f/dev/null"
 
+# Keep panes alive until the next case or cleanup, without reading replies.
+INPUT_HOLD='while :; do sleep 3600; done'
+
 TMP=$(mktemp)
 EXP=$(mktemp)
 trap 'rm -f "$TMP" "$EXP"; $TMUX kill-server 2>/dev/null' 0 1 15
@@ -37,10 +40,10 @@ start_pane_hlimit()
 
 	$TMUX kill-server 2>/dev/null
 	sleep 0.1
-	$TMUX new-session -d -x 1 -y 1 -s test-setup "sleep 2" || exit 1
+	$TMUX new-session -d -x 1 -y 1 -s test-setup "$INPUT_HOLD" || exit 1
 	$TMUX set-option -g history-limit "$hlimit" || exit 1
 	$TMUX new-session -d -x "$sx" -y "$sy" -s "$name" \
-	    "printf '$seq'; sleep 2" || exit 1
+	    "printf '$seq'; $INPUT_HOLD" || exit 1
 	$TMUX kill-session -t test-setup
 	sleep 0.3
 }

regress/input-keys.sh

@@ -22,7 +22,19 @@ assert_key () {
 	      clear-history -t$W \; \
 	      send-keys -t$W "$key" 'EOL' || exit 1
 
-	actual_code=$($TMUX capturep -pt$W | \
+	# cat echoes the keys back asynchronously, so wait for the EOL marker
+	# to reach the pane instead of capturing straight away.
+	i=0
+	while [ $i -lt 50 ]; do
+		screen=$($TMUX capturep -pt$W)
+		case "$screen" in
+		*EOL*) break ;;
+		esac
+		i=$((i + 1))
+		sleep 0.1
+	done
+
+	actual_code=$(printf '%s\n' "$screen" | \
 			      head -1 | \
 			      sed -e 's/EOL.*$//')
 

regress/input-malformed.sh

@@ -2,6 +2,38 @@
 
 . ./input-common.inc
 
+# Wait for the terminator and following text to reach the parser.
+check_discard()
+{
+	name=$1
+	printf 'OK\n' >"$EXP"
+	i=0
+	while [ "$i" -lt 300 ]; do
+		capture_grid "$name" >"$TMP"
+		cmp -s "$TMP" "$EXP" && return 0
+		sleep 0.05
+		i=$((i + 1))
+	done
+	fail "$name (timed out waiting for discard)"
+}
+
+# The missing-terminator timer may expire before the string limit is reached
+# on a slow build. Clear any payload printed after the timeout, then check
+# that the string did not change the title and normal output has resumed.
+test_discard()
+{
+	name=$1
+	prefix=$2
+	start_cmd "$name" 8 3 "$INPUT_HOLD"
+	$TMUX select-pane -T discard-test || exit 1
+	$TMUX respawn-pane -k \
+	    "perl -e 'print qq{$prefix}, q{x} x 1100000, qq{\e\\\\\e[H\e[2JOK}'; $INPUT_HOLD" || exit 1
+	check_discard "$name"
+	$TMUX display-message -p -t "$name:" '#{pane_title}' >"$TMP" || exit 1
+	printf 'discard-test\n' >"$EXP"
+	cmp "$TMP" "$EXP" || fail "$name title"
+}
+
 start_cmd csi-param-discard 8 3 \
     "perl -e 'print qq{\e[}, q{1} x 80, qq{\030OK}'; sleep 2"
 check_capture csi-param-discard 'OK'
@@ -10,13 +42,8 @@ start_cmd csi-interm-discard 8 3 \
     "perl -e 'print qq{\e[    \030OK}'; sleep 2"
 check_capture csi-interm-discard 'OK'
 
-start_cmd osc-discard 8 3 \
+test_discard osc-discard '\e]2;'
-    "perl -e 'print qq{\e]2;}, q{x} x 1100000, qq{\e\\\\OK}'; sleep 2"
+test_discard apc-discard '\e_'
-check_capture osc-discard 'OK'
-
-start_cmd apc-discard 8 3 \
-    "perl -e 'print qq{\e_}, q{x} x 1100000, qq{\e\\\\OK}'; sleep 2"
-check_capture apc-discard 'OK'
 
 start_pane unknown-csi 8 3 '\033[?9999zOK'
 check_capture unknown-csi 'OK'

regress/input-scroll.sh

@@ -51,7 +51,7 @@ $TMUX kill-server 2>/dev/null
 sleep 0.1
 $TMUX new-session -d -x 5 -y 3 -s history \; \
     set-option -g history-limit 3 \; \
-    respawn-pane -k "printf '01\n02\n03\n04\n05\n06'; sleep 2" || exit 1
+    respawn-pane -k "printf '01\n02\n03\n04\n05\n06'; $INPUT_HOLD" || exit 1
 sleep 0.3
 $TMUX capture-pane -pN -t history: -S - -E - | normalize_capture >"$TMP"
 printf "%s\n" '01

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/kill-session-zoomed.sh

@@ -0,0 +1,28 @@
+#!/bin/sh
+
+# Killing a session whose window is zoomed must not crash the server:
+# window_destroy used to unzoom the window, which resized the panes and
+# fired pane-resized with the window in the payload, and releasing that
+# reference destroyed the window a second time.
+
+PATH=/bin:/usr/bin
+TERM=screen
+
+[ -z "$TEST_TMUX" ] && TEST_TMUX=$(readlink -f ../tmux)
+TMUX="$TEST_TMUX -LtestA$$ -f/dev/null"
+$TMUX kill-server 2>/dev/null
+
+$TMUX -f/dev/null new -d -sfoo || exit 1
+$TMUX split-window -d -h -tfoo:0 || exit 1
+$TMUX resize-pane -Z -tfoo:0 || exit 1
+$TMUX new -d -sbar || exit 1
+$TMUX kill-session -tfoo || exit 1
+$TMUX has-session -tbar || exit 1
+
+# The same with the zoomed window in a session killed by kill-server.
+$TMUX new -d -sbaz || exit 1
+$TMUX split-window -d -v -tbaz:0 || exit 1
+$TMUX resize-pane -Z -tbaz:0 || exit 1
+$TMUX kill-server || exit 1
+
+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/mode-mutation.sh

@@ -269,6 +269,22 @@ test_customize_mode()
 	assert_alive "customize-mode exit"
 }
 
+test_customize_break_pane()
+{
+	start_client option-break
+	side=$($TMUX split-window -d -P -F '#{pane_id}' \
+	    -t option-break:0 'cat') || fail "customize split failed"
+
+	$TMUX customize-mode -t "$side" || fail "customize-mode failed"
+	wait_mode "$side" 1
+	$TMUX break-pane -d -s "$side" || fail "customize break-pane failed"
+
+	assert_alive "customize-mode break-pane"
+	wait_mode "$side" 1
+	$TMUX send-keys -t "$side" q || fail "customize-mode quit failed"
+	wait_mode "$side" 0
+}
+
 test_copy_mode()
 {
 	start_client copy-a 'i=0; while [ $i -lt 200 ]; do echo "copy mutation line $i"; i=$((i + 1)); done; cat'
@@ -302,6 +318,7 @@ test_choose_tree
 test_choose_buffer
 test_choose_client
 test_customize_mode
+test_customize_break_pane
 test_copy_mode
 cleanup
 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
@@ -192,13 +219,13 @@ check_fail "invalid window name: $(printf 'a\377b')" \
 	break-pane -d -n "$(printf 'a\377b')" -s "$p1" -t P:
 
 # join-pane can move a pane from one window to another without destroying
-# the source window if other panes remain. (On this branch move-pane is
+# the source window if other panes remain. move-pane does the same when no
-# reserved for floating panes, covered by floating-pane-geometry.sh.)
+# floating-pane movement flags are given.
 check_ok new-window -d -t P:5 -n other
 check_ok join-pane -d -s "$p1" -t P:5.0
 check_fmt 'P:5' '#{window_panes}' '2'
 check_fmt 'P:0' '#{window_panes}' '3'
-check_ok join-pane -d -v -s "$p1" -t "$p2"
+check_ok move-pane -d -v -s "$p1" -t "$p2"
 check_fmt 'P:0' '#{window_panes}' '4'
 check_fmt 'P:5' '#{window_panes}' '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/pipe-pane.sh

@@ -35,9 +35,9 @@ check_alive()
 
 # A pipe-pane -I child may write after the pane process has exited. With
 # remain-on-exit, the pane stays around but its bufferevent has been freed.
-check_ok new-session -d -s pipe -x 80 -y 24 'sleep 0.2'
+check_ok new-session -d -s pipe -x 80 -y 24 'sleep 1'
 check_ok set-option -t pipe:0 remain-on-exit on
-check_ok pipe-pane -t pipe:0.0 -I 'sleep 0.6; printf x'
+check_ok pipe-pane -t pipe:0.0 -I 'sleep 2; printf x'
 
 i=0
 while [ "$($TMUX display-message -p -t pipe:0.0 '#{pane_dead}')" != "1" ]; do
@@ -46,7 +46,7 @@ while [ "$($TMUX display-message -p -t pipe:0.0 '#{pane_dead}')" != "1" ]; do
 	sleep 0.1
 done
 
-sleep 0.7
+sleep 2
 check_alive
 
 $TMUX kill-server 2>/dev/null