cmd-attach-session: redraw pane styles when changing active pane

Call window_redraw_active_switch() before selecting a pane so differing window-style and window-active-style colours are updated immediately.\n\nAdd a regression test for selecting a pane through attach-session.
Merge branch 'master' into redraw-damage-rectangles
2026-09-18 02:54:45 +00:00 · 2026-09-14 04:36:57 +01:00 · 2026-09-09 14:05:48 +01:00 · 2026-08-25 10:49:46 +01:00 · 2026-08-25 10:25:29 +01:00 · 2026-08-25 10:14:49 +01:00
37 changed files with 2278 additions and 415 deletions
--- a/2
+++ b/2
@@ -130,8 +130,6 @@ CHANGES FROM 3.7c TO 3.8

 * 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.
--- a/cmd-attach-session.c
+++ b/cmd-attach-session.c
@@ -91,8 +91,10 @@ cmd_attach_session(struct cmdq_item *item, const char *tflag, int dflag,
 	wp = target.wp;

 	if (wl != NULL) {
-		if (wp != NULL)
+		if (wp != NULL) {
+			window_redraw_active_switch(wp->window, wp);
 			window_set_active_pane(wp->window, wp, 1);
+		}
 		session_set_current(s, wl);
 		if (wp != NULL)
 			cmd_find_from_winlink_pane(current, wl, wp, 0);
--- a/cmd-join-pane.c
+++ b/cmd-join-pane.c
@@ -300,6 +300,7 @@ cmd_join_pane_mouse_move(struct client *c, struct mouse_event *m)
 	struct window_pane	*wp;
 	struct layout_cell	*lc;
 	int			 y, ly, x, lx;
+	int			 old_xoff, old_yoff, old_sx, old_sy;

 	wp = cmd_mouse_pane(m, NULL, &wl);
 	if (wp == NULL) {
@@ -321,10 +322,17 @@ cmd_join_pane_mouse_move(struct client *c, struct mouse_event *m)
 		ly = m->statusat - 1;

 	if (x != lx || y != ly) {
+		old_xoff = wp->xoff;
+		old_yoff = wp->yoff;
+		old_sx = wp->sx;
+		old_sy = wp->sy;
+
 		lc->g.xoff += x - lx;
 		lc->g.yoff += y - ly;
 		layout_fix_panes(w, NULL);
-		server_redraw_window(w);
+
+		window_pane_redraw_floating(w, wp, old_xoff, old_yoff, old_sx,
+		    old_sy);
 		server_redraw_window_borders(w);
 	}
 }
--- a/cmd-resize-pane.c
+++ b/cmd-resize-pane.c
@@ -238,6 +238,7 @@ cmd_resize_pane_mouse_resize_move_floating(struct client *c,
 	int			 y, ly, x, lx, sx, sy, new_sx, new_sy;
 	int			 left, right;
 	int			 new_xoff, new_yoff, resizes = 0;
+	int			 old_xoff, old_yoff, old_sx, old_sy;

 	wp = cmd_mouse_pane(m, NULL, &wl);
 	if (wp == NULL) {
@@ -248,6 +249,10 @@ cmd_resize_pane_mouse_resize_move_floating(struct client *c,
 	lc = wp->layout_cell;
 	sx = wp->sx;
 	sy = wp->sy;
+	old_xoff = wp->xoff;
+	old_yoff = wp->yoff;
+	old_sx = (int)wp->sx;
+	old_sy = (int)wp->sy;
 	left = wp->xoff - 1;
 	right = wp->xoff + sx;
 	if (window_pane_scrollbar_reserve(wp) &&
@@ -347,7 +352,8 @@ cmd_resize_pane_mouse_resize_move_floating(struct client *c,
 	}
 	if (resizes != 0) {
 		layout_fix_panes(w, NULL);
-		server_redraw_window(w);
+		window_pane_redraw_floating(w, wp, old_xoff, old_yoff, old_sx,
+		    old_sy);
 		server_redraw_window_borders(w);
 	}
 }
--- a/cmd-split-window.c
+++ b/cmd-split-window.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: cmd-split-window.c,v 1.151 2026/09/10 11:02:18 nicm Exp $ */
+/* $OpenBSD: cmd-split-window.c,v 1.150 2026/08/20 09:19:24 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 = { "AbB:Cc:Dde:EfF:hIkl:KLMm:Op:PR:s:S:t:T:vWx:X:y:Y:Z", 0, -1, NULL },
-	.usage = "[-AbCDefhIkKLMOPvWZ] [-B border-lines] "
+	.args = { "AbB:Cc:de:EfF:hIkl:KLMm:Op:PR:s:S:t:T:vWx:X:y:Y:Z", 0, -1, NULL },
+	.usage = "[-AbCdefhIkKLMOPvWZ] [-B border-lines] "
 		 "[-c start-directory] [-e environment] "
 		 "[-F format] [-l size] [-m message] [-p percentage] "
 		 "[-s style] [-S active-border-style] "
@@ -219,8 +219,6 @@ cmd_split_window_exec(struct cmd *self, struct cmdq_item *item)
 		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) {
@@ -362,6 +360,7 @@ cmd_split_window_mouse_resize(struct client *c, struct mouse_event *m)
 	enum pane_lines		 lines;
 	u_int			 sx, sy;
 	int			 x, y, xoff, yoff, border;
+	int			 old_xoff, old_yoff, old_sx, old_sy;

 	if (c->tty.mouse_last_pane == -1)
 		return;
@@ -417,8 +416,15 @@ cmd_split_window_mouse_resize(struct client *c, struct mouse_event *m)
 	if (sy < PANE_MINIMUM)
 		sy = PANE_MINIMUM;

+	old_xoff = wp->xoff;
+	old_yoff = wp->yoff;
+	old_sx = wp->sx;
+	old_sy = wp->sy;
+
 	layout_set_size(lc, sx, sy, xoff, yoff);
 	layout_fix_panes(w, NULL);
-	server_redraw_window(w);
+
+	window_pane_redraw_floating(w, wp, old_xoff, old_yoff, old_sx,
+	    old_sy);
 	server_redraw_window_borders(w);
 }
--- a/layout-custom.c
+++ b/layout-custom.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: layout-custom.c,v 1.41 2026/09/09 09:01:19 nicm Exp $ */
+/* $OpenBSD: layout-custom.c,v 1.40 2026/09/09 07:03:39 nicm Exp $ */

 /*
 * Copyright (c) 2010 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -28,8 +28,8 @@
 #include "tmux.h"

 /*
- * Layouts can be represented as strings in a JSON format (v2). The version 1
- * format will be removed in the future and should no longer be used.
+ * Layouts can be represented as strings in a JSON format (v2). The legacy
+ * format (v1) will be removed in the future and should no longer be used.
 *
 * The current (v2) format is JSON. The top level has two keys:
 *    "V": version number, currently 2
@@ -57,9 +57,6 @@
 *    "z": z-index, if a floating pane
 */

-/* Maximum nesting depth for version 1 layouts. */
-#define LAYOUT_V1_MAX_DEPTH 1000
-
 /* Layout string. */
 struct layout_string {
 	char	*dat;
@@ -365,7 +362,7 @@ layout_append_v2(struct layout_cell *lc, struct layout_string *ls)
 	return (0);
 }

-/* Append information for a single cell in the version 1 format. */
+/* Append information for a single cell in the legacy (v1) format. */
 static int
 layout_append_v1(struct layout_cell *lc, struct layout_string *ls)
 {
@@ -781,7 +778,7 @@ layout_assign(struct window *w, struct layout_parse_ctx *pctx)
 		layout_assign_fallback(w, w->layout_root);
 }

-/* Construct a cell from the version 1 format. */
+/* Construct a cell from the legacy (v1) format. */
 static struct layout_cell *
 layout_construct_cell(struct layout_cell *lcparent, const char **layout)
 {
@@ -830,15 +827,12 @@ layout_construct_cell(struct layout_cell *lcparent, const char **layout)
 	return (lc);
 }

-/* Construct a layout from the version 1 format. */
+/* Construct a layout from the legacy (v1) format. */
 static struct layout_cell *
-layout_construct_v1(struct layout_cell *lcparent, const char **layout, u_int depth)
+layout_construct_v1(struct layout_cell *lcparent, const char **layout)
 {
 	struct layout_cell	*lc, *lcchild;

-	if (depth > LAYOUT_V1_MAX_DEPTH)
-		return (NULL);
-
 	lc = layout_construct_cell(lcparent, layout);
 	if (lc == NULL)
 		return (NULL);
@@ -861,7 +855,7 @@ layout_construct_v1(struct layout_cell *lcparent, const char **layout, u_int dep

 	do {
 		(*layout)++;
-		lcchild = layout_construct_v1(lc, layout, depth + 1);
+		lcchild = layout_construct_v1(lc, layout);
 		if (lcchild == NULL)
 			goto fail;
 		TAILQ_INSERT_TAIL(&lc->cells, lcchild, entry);
@@ -1074,8 +1068,7 @@ layout_construct(const char *input, struct layout_parse_ctx *pctx)
 			*pctx->cause = xstrdup("invalid layout checksum");
 			return (-1);
 		}
-		pctx->root = layout_construct_v1(NULL, &input, 0);
-		if (pctx->root == NULL) {
+		if ((pctx->root = layout_construct_v1(NULL, &input)) == NULL) {
 			*pctx->cause = xstrdup("invalid layout");
 			return (-1);
 		}
--- a/layout.c
+++ b/layout.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: layout.c,v 1.100 2026/09/11 08:16:14 nicm Exp $ */
+/* $OpenBSD: layout.c,v 1.99 2026/09/09 07:03:39 nicm Exp $ */

 /*
 * Copyright (c) 2009 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -469,7 +469,6 @@ layout_fix_panes(struct window *w, struct window_pane *skip)
 					sx = PANE_MINIMUM;
 				else
 					sx = sx - sb_w - sb_pad;
-			wp->flags |= PANE_REDRAWSCROLLBAR;
 		}

 		window_pane_resize(wp, sx, sy);
@@ -477,8 +476,11 @@ layout_fix_panes(struct window *w, struct window_pane *skip)
 		if (wp->xoff != old_xoff ||
 		    wp->yoff != old_yoff ||
 		    wp->sx != old_sx ||
-		    wp->sy != old_sy)
+		    wp->sy != old_sy) {
 			changed = 1;
+			if (window_pane_scrollbar_reserve(wp))
+				wp->flags |= PANE_REDRAWSCROLLBAR;
+		}
 	}
 	if (changed)
 		redraw_invalidate_scene(w);
@@ -768,49 +770,6 @@ 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)
@@ -831,11 +790,8 @@ 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)) {
-		layout_clamp_floating_panes(w, sx, sy);
-		layout_fix_panes(w, NULL);
+	if (lc->type == LAYOUT_WINDOWPANE && (lc->flags & LAYOUT_CELL_FLOATING))
 		return;
-	}
 	xchange = sx - lc->g.sx;
 	xlimit = layout_resize_check(w, lc, LAYOUT_LEFTRIGHT);
 	if (xchange < 0 && xchange < -xlimit)
@@ -865,7 +821,6 @@ 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);
 }

--- a/options-table.c
+++ b/options-table.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: options-table.c,v 1.246 2026/09/11 10:17:16 nicm Exp $ */
+/* $OpenBSD: options-table.c,v 1.244 2026/09/01 12:49:49 nicm Exp $ */

 /*
 * Copyright (c) 2011 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -76,8 +76,7 @@ static const char *options_table_pane_border_indicators_list[] = {
 	"off", "colour", "arrows", "both", NULL
 };
 static const char *options_table_pane_border_lines_list[] = {
-	"single", "double", "heavy", "simple", "number", "spaces", "none",
-	"rounded", NULL
+	"single", "double", "heavy", "simple", "number", "spaces", "none", NULL
 };
 static const char *options_table_popup_border_lines_list[] = {
 	"single", "double", "heavy", "simple", "rounded", "padded", "none", NULL
@@ -92,7 +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", "failed-key", NULL
+	"off", "on", "failed", "key", NULL
 };
 static const char *options_table_destroy_unattached_list[] = {
 	"off", "on", "keep-last", "keep-group", NULL
@@ -1699,8 +1698,7 @@ 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 after any exit ('key') or after a failure "
-		  "('failed-key'), or be automatically killed ('off' or "
+		  "pressed ('key') or be automatically killed ('off' or "
 		  "'failed') when the program inside exits."
 	},

--- a/popup.c
+++ b/popup.c
@@ -136,7 +136,8 @@ popup_reapply_styles(struct popup_data *pd)
 }

 static void
-popup_redraw_cb(const struct tty_ctx *ttyctx)
+popup_redraw_cb(const struct tty_ctx *ttyctx, __unused u_int py,
+    __unused u_int ny)
 {
 	struct popup_data	*pd = ttyctx->arg;

@@ -321,11 +322,60 @@ popup_resize_cb(__unused struct client *c, void *data)
 	}
 }

+/*
+ * Report damage for a popup's rectangle, given in raw client/tty
+ * coordinates. Status-line cells are outside the window scene - they have no
+ * corresponding window content and redraw_damage_window() can't reach them -
+ * so if the popup's rectangle overlaps the status line, force it to redraw
+ * separately. The rest of the rectangle is clipped to the actual pane area
+ * (above or below the status line, whichever side it's on) before being
+ * translated into window coordinates and reported the normal way, the same
+ * way mouse coordinates are translated elsewhere (e.g. cmd-join-pane.c,
+ * cmd-split-window.c).
+ */
+static void
+popup_damage(struct client *c, u_int px, u_int py, u_int sx, u_int sy)
+{
+	struct window	*w;
+	int		 statusat;
+	u_int		 ox, oy, osx, osy, lines, top, bottom, y0, y1;
+
+	if (c->session == NULL)
+		return;
+	w = c->session->curw->window;
+
+	lines = status_line_size(c);
+	statusat = status_at_line(c);
+	if (statusat >= 0 && py < (u_int)statusat + lines &&
+	    py + sy > (u_int)statusat)
+		c->flags |= (CLIENT_REDRAWSTATUS|CLIENT_REDRAWSTATUSALWAYS);
+
+	if (statusat == 0) {
+		top = lines;
+		bottom = c->tty.sy;
+	} else if (statusat > 0) {
+		top = 0;
+		bottom = statusat;
+	} else {
+		top = 0;
+		bottom = c->tty.sy;
+	}
+	y0 = (py > top) ? py : top;
+	y1 = (py + sy < bottom) ? py + sy : bottom;
+	if (y0 >= y1)
+		return;
+
+	tty_window_offset(&c->tty, &ox, &oy, &osx, &osy);
+	redraw_damage_window(w, px + ox, y0 - top + oy, sx, y1 - y0);
+}
+
 static void
 popup_handle_drag(struct client *c, struct popup_data *pd,
    struct mouse_event *m)
 {
 	u_int	px, py;
+	u_int	old_px = pd->px, old_py = pd->py;
+	u_int	old_sx = pd->sx, old_sy = pd->sy;

 	if (!MOUSE_DRAG(m->b))
 		pd->dragging = OFF;
@@ -348,7 +398,9 @@ popup_handle_drag(struct client *c, struct popup_data *pd,
 		pd->dy = m->y - pd->py;
 		pd->ppx = px;
 		pd->ppy = py;
-		server_redraw_client(c);
+
+		popup_damage(c, old_px, old_py, old_sx, old_sy);
+		c->flags |= CLIENT_REDRAWOVERLAY;
 	} else if (pd->dragging == SIZE) {
 		if (pd->border_lines == BOX_LINES_NONE) {
 			if (m->x < pd->px + 1)
@@ -375,7 +427,9 @@ popup_handle_drag(struct client *c, struct popup_data *pd,
 			if (pd->job != NULL)
 				job_resize(pd->job, pd->sx - 2, pd->sy - 2);
 		}
-		server_redraw_client(c);
+
+		popup_damage(c, old_px, old_py, old_sx, old_sy);
+		c->flags |= CLIENT_REDRAWOVERLAY;
 	}
 }

--- a/regress/attach-session-redraw.sh
+++ b/regress/attach-session-redraw.sh
@@ -0,0 +1,79 @@
+#!/bin/sh
+
+# Selecting a pane with attach-session from an already attached client must
+# redraw pane contents when window-style and window-active-style differ.
+
+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=$(mktemp -d) || exit 1
+INNER="$TEST_TMUX -Lattach-redraw-inner-$$ -f/dev/null"
+OUTER="$TEST_TMUX -Lattach-redraw-outer-$$ -f/dev/null"
+BEFORE=$DIR/before
+AFTER=$DIR/after
+
+fail()
+{
+	echo "$*" >&2
+	exit 1
+}
+
+cleanup()
+{
+	$OUTER kill-server 2>/dev/null
+	$INNER kill-server 2>/dev/null
+	rm -rf "$DIR"
+}
+trap cleanup 0 1 15
+
+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=$((i + 1))
+	done
+	fail "inner client did not attach"
+}
+
+LEFT=$($INNER new-session -dPF '#{pane_id}' -s inner -x 40 -y 8 \
+    "printf 'LEFT'; exec sleep 100") || exit 1
+$INNER set-option -g status off || exit 1
+$INNER set-option -g window-size manual || exit 1
+$INNER set-option -g default-terminal screen || exit 1
+$INNER split-window -h -t "$LEFT" "printf 'RIGHT'; exec sleep 100" || exit 1
+$INNER set-option -w -t "$LEFT" window-style bg=red || exit 1
+$INNER set-option -w -t "$LEFT" window-active-style bg=blue || exit 1
+$INNER bind-key -n x attach-session -t "$LEFT" || exit 1
+
+$OUTER new-session -d -s outer -x 40 -y 8 'sleep 100' || exit 1
+$OUTER set-option -g status off || exit 1
+$OUTER set-option -g window-size manual || exit 1
+$OUTER set-option -g default-terminal screen || exit 1
+$OUTER respawn-pane -k -t outer:0.0 \
+    "$TEST_TMUX -Lattach-redraw-inner-$$ -f/dev/null attach-session -t inner" ||
+    exit 1
+
+wait_for_client
+sleep 1
+$OUTER send-keys -t outer:0.0 x || exit 1
+sleep 1
+[ "$($INNER display-message -p -t inner '#{pane_id}')" = "$LEFT" ] ||
+    fail "attach-session did not select the target pane"
+$OUTER capture-pane -pe -t outer:0.0 >"$BEFORE" || exit 1
+
+# A forced redraw produces the correct scene. It must be identical to the
+# scene drawn immediately by attach-session.
+$INNER refresh-client -t "$CLIENT" || exit 1
+sleep 1
+$OUTER capture-pane -pe -t outer:0.0 >"$AFTER" || exit 1
+cmp -s "$BEFORE" "$AFTER" ||
+    fail "attach-session left stale active/inactive pane styles"
+
+exit 0
--- a/regress/control-client-sanity.sh
+++ b/regress/control-client-sanity.sh
@@ -30,11 +30,8 @@ killw
 EOF
 sleep 1
 $TMUX has || exit 1
-# Use a control client to request legacy layouts, keeping only pane lines
-# from the control protocol output.
-$TMUX -C lsp -aF '#{pane_id} #{window_layout}' |
-	grep '^%[0-9]' >$TMP || exit 1
-cat <<EOF|cmp $TMP - || exit 1
+$TMUX lsp -aF '#{pane_id} #{window_layout}' >$TMP || exit 1
+cat <<EOF|cmp -s $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]
--- a/regress/floating-pane-drag-ghost.sh
+++ b/regress/floating-pane-drag-ghost.sh
@@ -0,0 +1,108 @@
+#!/bin/sh
+
+# Regression test for a floating-pane drag bug: cmd_resize_pane_redraw_floating()
+# (cmd-resize-pane.c) reported damage for just a dragged floating pane's
+# content rectangle, not the one-cell border frame drawn around it (see the
+# "floating" case in screen-redraw.c, which draws that frame at
+# xoff-1/yoff-1 through xoff+sx/yoff+sy - one cell outside the pane's own
+# content area). Damage scoped to only the content area left the frame's
+# previous position undrawn as the pane moved, so dragging it left a trail
+# of un-erased border frames behind - visible as several "corners" stacked
+# up rather than just the pane's current one.
+#
+# This bug has nothing to do with images - it reproduces with a plain
+# floating pane and no image support required.
+
+PATH=/bin:/usr/bin
+TERM=screen
+LC_ALL=C.UTF-8
+export TERM LC_ALL
+
+[ -z "$TEST_TMUX" ] && TEST_TMUX=$(readlink -f ../tmux)
+TMUX="$TEST_TMUX -LtestA$$ -f/dev/null"
+TMUX2="$TEST_TMUX -LtestB$$ -f/dev/null"
+
+cleanup()
+{
+	$TMUX kill-server >/dev/null 2>&1
+	$TMUX2 kill-server >/dev/null 2>&1
+}
+fail()
+{
+	echo "$*" >&2
+	cleanup
+	exit 1
+}
+
+# drag STARTCOL STARTROW ENDCOL ENDROW
+#
+# Write a plain (unmodified) SGR button-1 press, drag update and release at
+# 1-based positions to the outer pane holding the inner client - this
+# matches the default MouseDown1Border/MouseDrag1Border bindings used to
+# move or resize a floating pane by its border.
+drag()
+{
+	scol="$1"
+	srow="$2"
+	ecol="$3"
+	erow="$4"
+
+	seq=$(printf '\033[<0;%s;%sM' "$scol" "$srow")
+	$TMUX2 send-keys -t "$OUTER" -l "$seq" 2>/dev/null
+	sleep 0.2
+	seq=$(printf '\033[<32;%s;%sM' "$ecol" "$erow")
+	$TMUX2 send-keys -t "$OUTER" -l "$seq" 2>/dev/null
+	sleep 0.2
+	seq=$(printf '\033[<0;%s;%sm' "$ecol" "$erow")
+	$TMUX2 send-keys -t "$OUTER" -l "$seq" 2>/dev/null
+	sleep 1
+}
+
+cleanup
+
+TMP=$(mktemp)
+trap "cleanup; rm -f $TMP" 0 1 15
+
+$TMUX new-session -d -s inner -x 60 -y 20 'sh -c "sleep 100"' || exit 1
+$TMUX set -g mouse on
+$TMUX set -g default-command 'sh -c "sleep 100"'
+
+FLOAT=$($TMUX new-pane -d -PF '#{pane_id}' -x 16 -y 5 -X 5 -Y 5) ||
+	fail "new-pane -X -Y failed"
+FTOP=$($TMUX display-message -p -t "$FLOAT" '#{pane_top}')
+FLEFT=$($TMUX display-message -p -t "$FLOAT" '#{pane_left}')
+FWIDTH=$($TMUX display-message -p -t "$FLOAT" '#{pane_width}')
+
+$TMUX2 new-session -d -x 60 -y 20 "$TMUX attach -t inner" || exit 1
+sleep 1
+OUTER=$($TMUX2 list-panes -F '#{pane_id}' | head -1)
+[ -n "$OUTER" ] || fail "No outer pane."
+
+# Sanity check: exactly one floating pane, so exactly one top-left corner,
+# before dragging anything.
+$TMUX2 capturep -p -t "$OUTER" >$TMP || fail "capture failed"
+n=$(grep -o '┌' $TMP | wc -l)
+[ "$n" -eq 1 ] || fail "sanity: expected 1 corner before drag, found $n"
+
+# Drag the floating pane by its top border (row FTOP-1, some column within
+# its width) down several rows in a few separate steps, then release. A
+# single drag() call already does press/motion/release, so call it several
+# times in a row to simulate a multi-step real drag.
+GRABCOL=$((FLEFT + FWIDTH / 2))
+STARTROW=$FTOP
+i=0
+while [ $i -lt 6 ]; do
+	newrow=$((STARTROW + i + 1))
+	drag $((GRABCOL + 1)) $((STARTROW + i)) $((GRABCOL + 1)) $newrow
+	i=$((i + 1))
+done
+
+$TMUX2 capturep -p -t "$OUTER" >$TMP || fail "capture failed"
+
+# Exactly one top-left corner should remain - the pane's current position.
+# This is expected to fail before the fix: multiple corners (a trail of
+# un-erased frames) would remain from the intermediate drag positions.
+n=$(grep -o '┌' $TMP | wc -l)
+[ "$n" -eq 1 ] || fail "expected exactly 1 corner after drag, found $n (ghost frames left behind)"
+
+exit 0
--- a/regress/floating-pane-drag-scrollbar-strip.sh
+++ b/regress/floating-pane-drag-scrollbar-strip.sh
@@ -0,0 +1,140 @@
+#!/bin/sh
+
+# Regression test: dragging a floating pane across another pane's ordinary
+# content must not redraw that other pane's scrollbar, unless the drag
+# actually crosses the scrollbar's own strip.
+#
+# cmd_resize_pane_redraw_floating() (cmd-resize-pane.c) used to flag
+# PANE_REDRAWSCROLLBAR on any pane whose whole *body* intersected the
+# floating pane's old or new rectangle, rather than just its narrow
+# scrollbar strip - so dragging a floating pane back and forth over an
+# ordinary tiled pane's content (never touching its scrollbar) still
+# needlessly redrew that pane's scrollbar on every motion step. See
+# tmux-image-redraw-known-bugs.md for the full write-up.
+#
+# This is checked by giving the non-dragged pane a distinctive scrollbar
+# colour and counting how many times its SGR code appears in the client's
+# raw output while the floating pane is dragged vertically over that pane's
+# body, well clear of its scrollbar column: with the fix, it should never
+# reappear after the initial draw.
+
+PATH=/bin:/usr/bin
+TERM=screen
+LC_ALL=C.UTF-8
+export TERM LC_ALL
+
+[ -z "$TEST_TMUX" ] && TEST_TMUX=$(readlink -f ../tmux)
+TMUX="$TEST_TMUX -LtestA$$ -f/dev/null"
+TMUX2="$TEST_TMUX -LtestB$$ -f/dev/null"
+
+cleanup()
+{
+	$TMUX kill-server >/dev/null 2>&1
+	$TMUX2 kill-server >/dev/null 2>&1
+}
+fail()
+{
+	echo "$*" >&2
+	cleanup
+	exit 1
+}
+
+# drag STARTCOL STARTROW ENDCOL ENDROW
+drag()
+{
+	scol="$1"
+	srow="$2"
+	ecol="$3"
+	erow="$4"
+
+	seq=$(printf '\033[<0;%s;%sM' "$scol" "$srow")
+	$TMUX2 send-keys -t "$OUTER" -l "$seq" 2>/dev/null
+	sleep 0.2
+	seq=$(printf '\033[<32;%s;%sM' "$ecol" "$erow")
+	$TMUX2 send-keys -t "$OUTER" -l "$seq" 2>/dev/null
+	sleep 0.2
+	seq=$(printf '\033[<0;%s;%sm' "$ecol" "$erow")
+	$TMUX2 send-keys -t "$OUTER" -l "$seq" 2>/dev/null
+	sleep 0.5
+}
+
+cleanup
+
+TMP=$(mktemp)
+trap "cleanup; rm -f $TMP" 0 1 15
+
+$TMUX new-session -d -s inner -x 60 -y 20 'sh -c "sleep 100"' || exit 1
+$TMUX set -g mouse on || fail "set mouse failed"
+$TMUX set -g default-command 'sh -c "sleep 100"' || fail "set default-command failed"
+$TMUX set -g pane-scrollbars on || fail "set pane-scrollbars failed"
+
+$TMUX split-window -h -t inner 'sh -c "sleep 100"' || fail "split-window failed"
+
+PANES=$($TMUX list-panes -t inner -F '#{pane_id} #{pane_left}')
+LEFT=$(echo "$PANES" | sort -k2 -n | head -1 | cut -d' ' -f1)
+[ -n "$LEFT" ] || fail "could not identify left pane"
+
+# A distinctive scrollbar colour for the non-dragged (left) pane only.
+$TMUX set -p -t "$LEFT" pane-scrollbars-style 'fg=colour201,bg=colour17' ||
+	fail "set pane-scrollbars-style failed"
+
+ALEFT=$($TMUX display-message -p -t "$LEFT" '#{pane_left}')
+ATOP=$($TMUX display-message -p -t "$LEFT" '#{pane_top}')
+AWIDTH=$($TMUX display-message -p -t "$LEFT" '#{pane_width}')
+AHEIGHT=$($TMUX display-message -p -t "$LEFT" '#{pane_height}')
+[ "$AWIDTH" -gt 15 ] || fail "left pane too narrow for this test ($AWIDTH)"
+
+# A small floating pane placed well inside the left pane's content area,
+# clear of its (right-hand) scrollbar column by several columns.
+FLOAT=$($TMUX new-pane -d -PF '#{pane_id}' -x 8 -y 5 \
+    -X $((ALEFT + 2)) -Y $((ATOP + 2))) || fail "new-pane -X -Y failed"
+FTOP=$($TMUX display-message -p -t "$FLOAT" '#{pane_top}')
+FLEFT=$($TMUX display-message -p -t "$FLOAT" '#{pane_left}')
+FWIDTH=$($TMUX display-message -p -t "$FLOAT" '#{pane_width}')
+[ $((FLEFT + FWIDTH + 3)) -lt $((ALEFT + AWIDTH)) ] ||
+	fail "sanity: floating pane too close to the scrollbar column"
+
+# Start the outer session with a plain shell, then start capturing before
+# triggering the attach - starting the attach as the outer pane's initial
+# command would mean pipe-pane only starts after the attach-driven initial
+# redraw (which draws the scrollbars) has already happened, missing it.
+$TMUX2 new-session -d -x 60 -y 20 || exit 1
+OUTER=$($TMUX2 list-panes -F '#{pane_id}' | head -1)
+[ -n "$OUTER" ] || fail "No outer pane."
+$TMUX2 pipe-pane -t "$OUTER" -O "cat >$TMP" || fail "pipe-pane failed"
+$TMUX2 send-keys -t "$OUTER" -l "$TMUX attach -t inner" || fail "send attach failed"
+$TMUX2 send-keys -t "$OUTER" Enter || fail "send enter failed"
+sleep 1
+
+# Sanity check: the distinctive scrollbar colour reaches the client at all.
+grep -qa '48;5;201' $TMP || fail "sanity: scrollbar colour never reached the client"
+: >$TMP
+
+# Drag the floating pane straight up and down by its top border, staying at
+# a fixed column the whole time - this never crosses the left pane's
+# scrollbar strip, only its ordinary content.
+GRABCOL=$((FLEFT + FWIDTH / 2))
+row=$FTOP
+i=0
+while [ $i -lt 6 ]; do
+	newrow=$((row + 1))
+	drag $GRABCOL $row $GRABCOL $newrow
+	row=$newrow
+	i=$((i + 1))
+done
+i=0
+while [ $i -lt 6 ]; do
+	newrow=$((row - 1))
+	drag $GRABCOL $row $GRABCOL $newrow
+	row=$newrow
+	i=$((i + 1))
+done
+
+# The scrollbar colour should never reappear - its geometry never changed,
+# and the drag never crossed its column. This is expected to fail before
+# the fix - see the header comment.
+n=$(grep -ac '48;5;201' $TMP)
+[ "$n" -eq 0 ] ||
+	fail "left pane's scrollbar was redrawn $n times while dragging over its body only"
+
+exit 0
--- a/regress/floating-pane-geometry.sh
+++ b/regress/floating-pane-geometry.sh
@@ -268,149 +268,5 @@ $TMUX kill-pane -t "$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
-
 $TMUX kill-server 2>/dev/null
 exit 0
--- a/regress/floating-pane-status-format.sh
+++ b/regress/floating-pane-status-format.sh
@@ -0,0 +1,102 @@
+#!/bin/sh
+
+# Resizing a floating pane must refresh session status formats which depend on
+# its geometry, not only the pane scene and borders.
+
+PATH=/bin:/usr/bin
+TERM=screen
+LC_ALL=C.UTF-8
+export PATH TERM LC_ALL
+
+[ -z "$TEST_TMUX" ] && TEST_TMUX=$(readlink -f ../tmux)
+
+DIR=$(mktemp -d) || exit 1
+INNER="$TEST_TMUX -Lfloating-status-inner-$$ -f/dev/null"
+OUTER="$TEST_TMUX -Lfloating-status-outer-$$ -f/dev/null"
+CAPTURE=$DIR/capture
+
+fail()
+{
+	echo "$*" >&2
+	[ -s "$CAPTURE" ] && cat "$CAPTURE" >&2
+	exit 1
+}
+
+cleanup()
+{
+	$OUTER kill-server 2>/dev/null
+	$INNER kill-server 2>/dev/null
+	rm -rf "$DIR"
+}
+trap cleanup 0 1 15
+
+wait_for_client()
+{
+	i=0
+	while [ "$i" -lt 50 ]; do
+		CLIENT=$($INNER list-clients -F '#{client_name}' 2>/dev/null)
+		[ -n "$CLIENT" ] && return 0
+		sleep 0.1
+		i=$((i + 1))
+	done
+	fail "inner client did not attach"
+}
+
+wait_outer_has_status()
+{
+	marker=$1
+	i=0
+	while [ "$i" -lt 50 ]; do
+		$OUTER capture-pane -p -t outer:0.0 >"$CAPTURE" 2>/dev/null || true
+		tail -1 "$CAPTURE" | grep -q "$marker" && return 0
+		sleep 0.1
+		i=$((i + 1))
+	done
+	fail "outer client status did not show $marker"
+}
+
+mouse()
+{
+	sequence=$(printf '\033[<%s;%s;%s%s' "$1" "$2" "$3" "$4")
+	$OUTER send-keys -t outer:0.0 -l "$sequence" || exit 1
+	sleep 0.1
+}
+
+$INNER new-session -d -s inner -x 50 -y 12 'sleep 100' || exit 1
+FLOAT=$($INNER new-pane -PF '#{pane_id}' -x 10 -y 5 -X 5 -Y 3 \
+    'sleep 100') || fail "could not create floating pane"
+$INNER set-option -g window-size manual || exit 1
+$INNER set-option -g mouse on || exit 1
+$INNER set-option -g status on || exit 1
+$INNER set-option -g status-position bottom || exit 1
+$INNER set-option -g status-left 'WIDTH=#{pane_width}' || exit 1
+$INNER set-option -g status-right '' || exit 1
+$INNER set-option -g status-interval 0 || exit 1
+
+$OUTER new-session -d -s outer -x 50 -y 12 'sleep 100' || exit 1
+$OUTER set-option -g status off || exit 1
+$OUTER set-option -g window-size manual || exit 1
+$OUTER respawn-pane -k -t outer:0.0 \
+    "$TEST_TMUX -Lfloating-status-inner-$$ -f/dev/null attach-session -t inner" ||
+    exit 1
+
+wait_for_client
+OLD_WIDTH=$($INNER display-message -p -t "$FLOAT" '#{pane_width}')
+wait_outer_has_status "WIDTH=$OLD_WIDTH"
+
+RIGHT=$($INNER display-message -p -t "$FLOAT" '#{pane_right}')
+TOP=$($INNER display-message -p -t "$FLOAT" '#{pane_top}')
+X=$((RIGHT + 2))
+Y=$((TOP + 2))
+
+# Grab the right frame and enlarge the floating pane.
+mouse 0 "$X" "$Y" M
+mouse 32 "$((X + 1))" "$Y" M
+mouse 32 "$((X + 8))" "$Y" M
+mouse 0 "$((X + 8))" "$Y" m
+
+NEW_WIDTH=$($INNER display-message -p -t "$FLOAT" '#{pane_width}')
+[ "$NEW_WIDTH" -ne "$OLD_WIDTH" ] || fail "floating pane was not resized"
+wait_outer_has_status "WIDTH=$NEW_WIDTH"
+
+exit 0
--- a/regress/modal-pane.sh
+++ b/regress/modal-pane.sh
@@ -337,9 +337,9 @@ $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 "$p0" \
+modal=$($TMUX new-pane -OKPF '#{pane_id}' -t "$p0" \
    -x 20 -y 5 -X 20 -Y 10 'cat') ||
-	fail "new-pane -ODK failed"
+	fail "new-pane -OK failed"
 sleep 1
 $TMUX2 send-keys -t "$OUTER" C-b x z Enter
 sleep 1
@@ -356,50 +356,9 @@ 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'
--- a/regress/options-values.sh
+++ b/regress/options-values.sh
@@ -86,11 +86,6 @@ check_value "-gv status-keys" "vi"
 check_fail "unknown value: bogus" set -g status-keys bogus
 check_value "-gv status-keys" "vi"

-# pane-border-lines accepts rounded as a pane border style.
-check_ok set -gw pane-border-lines rounded
-check_value "-gwv pane-border-lines" "rounded"
-check_ok set -gw pane-border-lines single
-
 # --- flag options ---------------------------------------------------------
 #
 # focus-events is an on/off flag.  Setting with no value toggles it; explicit
--- a/regress/pane-ops.sh
+++ b/regress/pane-ops.sh
@@ -104,25 +104,6 @@ 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.

@@ -328,12 +309,12 @@ 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=$(pane_layout P:0)
+layout=$($TMUX display-message -p -t P:0 '#{window_layout}')
 check_ok select-pane -t "$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_fmt P:0 '#{window_layout}' "$layout"

 check_ok select-pane -t "$p0"
 check_ok resize-pane -Z -t "$p0"
@@ -341,7 +322,7 @@ 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"
+check_fmt P:0 '#{window_layout}' "$layout"

 # Directional selection temporarily restores the full layout to find its
 # neighbour, then follows the same unzoom or -Z transfer rules.
@@ -359,7 +340,7 @@ 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"
+check_fmt P:0 '#{window_layout}' "$layout"

 # The last-pane path has separate zoom handling, both with and without -Z.
 check_ok select-pane -t "$p0"
@@ -376,7 +357,7 @@ check_ok select-pane -l -Z -t P:0
 check_fmt "$p0" '#{window_zoomed_flag}:#{pane_zoomed_flag}:#{pane_active}' \
 	'1:1:1'
 check_ok resize-pane -Z -t "$p0"
-check_layout P:0 "$layout"
+check_fmt P:0 '#{window_layout}' "$layout"

 # Killing either a hidden ordinary pane or the zoom target unzooms.
 check_ok new-window -d -t P:12 -n zoom-kill 'cat'
--- a/regress/popup-drag-pane-prompt.sh
+++ b/regress/popup-drag-pane-prompt.sh
@@ -0,0 +1,97 @@
+#!/bin/sh
+
+# Moving a popup away from a pane prompt must recompose the prompt over the
+# pane contents restored by damage redraw.
+
+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=$(mktemp -d) || exit 1
+INNER="$TEST_TMUX -Lpopup-prompt-inner-$$ -f/dev/null"
+OUTER="$TEST_TMUX -Lpopup-prompt-outer-$$ -f/dev/null"
+CAPTURE=$DIR/capture
+POPUP_PID=
+
+fail()
+{
+	echo "$*" >&2
+	[ -s "$CAPTURE" ] && cat "$CAPTURE" >&2
+	exit 1
+}
+
+cleanup()
+{
+	[ -n "$POPUP_PID" ] && kill "$POPUP_PID" 2>/dev/null
+	$OUTER kill-server 2>/dev/null
+	$INNER kill-server 2>/dev/null
+	rm -rf "$DIR"
+}
+trap cleanup 0 1 15
+
+wait_for_client()
+{
+	i=0
+	while [ "$i" -lt 50 ]; do
+		CLIENT=$($INNER list-clients -F '#{client_name}' 2>/dev/null)
+		[ -n "$CLIENT" ] && return 0
+		sleep 0.1
+		i=$((i + 1))
+	done
+	fail "inner client did not attach"
+}
+
+wait_outer_has()
+{
+	marker=$1
+	i=0
+	while [ "$i" -lt 50 ]; do
+		$OUTER capture-pane -p -t outer:0.0 >"$CAPTURE" 2>/dev/null || true
+		grep -q "$marker" "$CAPTURE" && return 0
+		sleep 0.1
+		i=$((i + 1))
+	done
+	fail "outer client did not show $marker"
+}
+
+mouse()
+{
+	sequence=$(printf '\033[<%s;%s;%s%s' "$1" "$2" "$3" "$4")
+	$OUTER send-keys -t outer:0.0 -l "$sequence" || exit 1
+	sleep 0.1
+}
+
+C="sh -c 'i=1; while [ \$i -le 10 ]; do printf \"\\033[%d;1HAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\" \$i; i=\$((i + 1)); done; exec sleep 100'"
+
+$INNER new-session -d -s inner -x 40 -y 10 "$C" || exit 1
+$INNER set-option -g status off || exit 1
+$INNER set-option -g window-size manual || exit 1
+$INNER set-option -g mouse on || exit 1
+
+$OUTER new-session -d -s outer -x 40 -y 10 'sleep 100' || exit 1
+$OUTER set-option -g status off || exit 1
+$OUTER set-option -g window-size manual || exit 1
+$OUTER respawn-pane -k -t outer:0.0 \
+    "$TEST_TMUX -Lpopup-prompt-inner-$$ -f/dev/null attach-session -t inner" ||
+    exit 1
+
+wait_for_client
+$INNER command-prompt -b -P -t "$CLIENT" -p 'PROMPT-MARK>' \
+    'display-message -- %1' || exit 1
+wait_outer_has PROMPT-MARK
+
+$INNER display-popup -t "$CLIENT" -x 0 -y 10 -w 16 -h 3 -E \
+    "sh -c 'printf POPUP-MARKER; exec sleep 100'" &
+POPUP_PID=$!
+wait_outer_has POPUP-MARKER
+
+mouse 0 10 8 M
+mouse 32 11 8 M
+mouse 32 25 4 M
+mouse 0 25 4 m
+wait_outer_has PROMPT-MARK
+
+exit 0
--- a/regress/popup-drag-redraw.sh
+++ b/regress/popup-drag-redraw.sh
@@ -0,0 +1,155 @@
+#!/bin/sh
+
+# Moving and resizing a popup must restore its old rectangle, including pane
+# border status, on the attached client's terminal.
+
+PATH=/bin:/usr/bin
+TERM=screen
+LC_ALL=C.UTF-8
+export PATH TERM LC_ALL
+
+[ -z "$TEST_TMUX" ] && TEST_TMUX=$(readlink -f ../tmux)
+
+DIR=$(mktemp -d) || exit 1
+INNER="$TEST_TMUX -Lpopup-drag-inner-$$ -f/dev/null"
+OUTER="$TEST_TMUX -Lpopup-drag-outer-$$ -f/dev/null"
+BASE=$DIR/base
+CAPTURE=$DIR/capture
+RAW=$DIR/raw
+POPUP_PID=
+
+fail()
+{
+	echo "$*" >&2
+	[ -s "$CAPTURE" ] && cat "$CAPTURE" >&2
+	exit 1
+}
+
+cleanup()
+{
+	[ -n "$POPUP_PID" ] && kill "$POPUP_PID" 2>/dev/null
+	$OUTER kill-server 2>/dev/null
+	$INNER kill-server 2>/dev/null
+	rm -rf "$DIR"
+}
+trap cleanup 0 1 15
+
+wait_for_client()
+{
+	i=0
+	while [ "$i" -lt 50 ]; do
+		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_outer_has()
+{
+	marker=$1
+	i=0
+	while [ "$i" -lt 50 ]; do
+		$OUTER capture-pane -p -t outer:0.0 >"$CAPTURE" 2>/dev/null || true
+		grep -q "$marker" "$CAPTURE" && return 0
+		sleep 0.1
+		i=$((i + 1))
+	done
+	fail "outer client did not show $marker"
+}
+
+wait_rows_match()
+{
+	first=$1
+	last=$2
+	i=0
+	while [ "$i" -lt 50 ]; do
+		$OUTER capture-pane -p -t outer:0.0 >"$CAPTURE" 2>/dev/null || true
+		sed -n "${first},${last}p" "$BASE" >"$DIR/want"
+		sed -n "${first},${last}p" "$CAPTURE" >"$DIR/got"
+		cmp -s "$DIR/want" "$DIR/got" && return 0
+		sleep 0.1
+		i=$((i + 1))
+	done
+	fail "outer rows $first-$last were not restored"
+}
+
+mouse()
+{
+	sequence=$(printf '\033[<%s;%s;%s%s' "$1" "$2" "$3" "$4")
+	$OUTER send-keys -t outer:0.0 -l "$sequence" || exit 1
+	sleep 0.1
+}
+
+# A left-button border drag moves the popup. The first motion starts the drag;
+# the second changes its position.
+move_popup()
+{
+	mouse 0 10 1 M
+	mouse 32 11 1 M
+	mouse 32 26 8 M
+	mouse 0 26 8 m
+}
+
+# A right-button bottom-right-border drag resizes the popup.
+resize_popup()
+{
+	mouse 2 "$1" "$2" M
+	mouse 34 "$3" "$4" M
+	mouse 34 "$5" "$6" M
+	mouse 2 "$5" "$6" m
+}
+
+C="sh -c 'i=0; while [ \$i -lt 20 ]; do printf \"\\033[%d;1HBG-ROW-%02d-abcdefghijklmnopqrstuvwxyz0123456789\" \$((i + 1)) \$i; i=\$((i + 1)); done; printf \"\\033[19;45H\\033[38;5;201mSCOPE\\033[0m\"; exec sleep 100'"
+
+$INNER new-session -d -s inner -x 60 -y 20 "$C" || exit 1
+$INNER set-option -g status off || exit 1
+$INNER set-option -g window-size manual || exit 1
+$INNER set-option -g mouse on || exit 1
+$INNER set-option -w pane-border-status top || exit 1
+$INNER set-option -w pane-border-format 'DAMAGE-STATUS-RESTORED' || exit 1
+
+$OUTER new-session -d -s outer -x 60 -y 20 'sleep 100' || exit 1
+$OUTER set-option -g status off || exit 1
+$OUTER set-option -g window-size manual || exit 1
+$OUTER set-option -g default-terminal screen-256color || exit 1
+$OUTER pipe-pane -O -t outer:0.0 "cat >'$RAW'" || exit 1
+$OUTER respawn-pane -k -t outer:0.0 \
+    "$TEST_TMUX -Lpopup-drag-inner-$$ -f/dev/null attach-session -t inner" ||
+    exit 1
+
+wait_for_client
+wait_outer_has SCOPE
+grep -qa '38;5;201' "$RAW" || fail "scope colour was not drawn initially"
+$OUTER capture-pane -p -t outer:0.0 >"$BASE" || exit 1
+grep -q DAMAGE-STATUS-RESTORED "$BASE" ||
+    fail "pane border status was not visible before popup"
+
+$INNER display-popup -t "$CLIENT" -x 0 -y 0 -w 28 -h 6 -E \
+    "sh -c 'printf POPUP-MARKER; exec sleep 100'" &
+POPUP_PID=$!
+wait_outer_has POPUP-MARKER
+$OUTER pipe-pane -t outer:0.0 || exit 1
+$OUTER pipe-pane -O -t outer:0.0 "cat >'$RAW'" || exit 1
+
+move_popup
+wait_rows_match 1 6
+$OUTER pipe-pane -t outer:0.0 || exit 1
+grep -qa '38;5;201' "$RAW" &&
+    fail "popup move redrew content outside its old and new rectangles"
+grep -q DAMAGE-STATUS-RESTORED "$CAPTURE" ||
+    fail "pane border status was not restored after popup move"
+
+# The moved popup is 28x6 at zero-based 16,7. Shrink it to 21x3, then require
+# the three rows vacated at the bottom to match the original scene.
+resize_popup 44 13 43 13 38 11
+wait_rows_match 11 13
+
+# Grow it back to 28x6 and require a single, intact popup frame.
+resize_popup 37 10 36 10 45 14
+wait_outer_has POPUP-MARKER
+corners=$(grep -o '┌' "$CAPTURE" | wc -l)
+[ "$corners" -eq 1 ] || fail "expected one popup frame, found $corners"
+
+exit 0
--- a/regress/popup-drag-status-line.sh
+++ b/regress/popup-drag-status-line.sh
@@ -0,0 +1,165 @@
+#!/bin/sh
+
+# Moving a popup away from the tmux status area must restore status and window
+# cells. Window damage alone cannot describe cells outside the window scene,
+# and top status lines must be removed before translating to window rows.
+
+PATH=/bin:/usr/bin
+TERM=screen
+LC_ALL=C.UTF-8
+export PATH TERM LC_ALL
+
+[ -z "$TEST_TMUX" ] && TEST_TMUX=$(readlink -f ../tmux)
+
+DIR=$(mktemp -d) || exit 1
+BASE=$DIR/base
+CAPTURE=$DIR/capture
+INNER=
+OUTER=
+POPUP_PID=
+N=0
+
+fail()
+{
+	echo "$*" >&2
+	[ -s "$CAPTURE" ] && cat "$CAPTURE" >&2
+	exit 1
+}
+
+cleanup_scene()
+{
+	[ -n "$POPUP_PID" ] && kill "$POPUP_PID" 2>/dev/null
+	[ -n "$OUTER" ] && $OUTER kill-server 2>/dev/null
+	[ -n "$INNER" ] && $INNER kill-server 2>/dev/null
+	POPUP_PID=
+}
+
+cleanup()
+{
+	cleanup_scene
+	rm -rf "$DIR"
+}
+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_outer_has()
+{
+	marker=$1
+	i=0
+	while [ "$i" -lt 50 ]; do
+		$OUTER capture-pane -p -t outer:0.0 >"$CAPTURE" 2>/dev/null || true
+		grep -q "$marker" "$CAPTURE" && return 0
+		sleep 0.1
+		i=$((i + 1))
+	done
+	fail "outer client did not show $marker"
+}
+
+wait_rows_restored()
+{
+	first=$1
+	last=$2
+	i=0
+	while [ "$i" -lt 50 ]; do
+		$OUTER capture-pane -p -t outer:0.0 >"$CAPTURE" 2>/dev/null || true
+		sed -n "${first},${last}p" "$BASE" >"$DIR/want"
+		sed -n "${first},${last}p" "$CAPTURE" >"$DIR/got"
+		cmp -s "$DIR/want" "$DIR/got" && return 0
+		sleep 0.1
+		i=$((i + 1))
+	done
+	fail "rows $first-$last under the old popup were not restored"
+}
+
+mouse()
+{
+	sequence=$(printf '\033[<%s;%s;%s%s' "$1" "$2" "$3" "$4")
+	$OUTER send-keys -t outer:0.0 -l "$sequence" || exit 1
+	sleep 0.1
+}
+
+setup()
+{
+	position=$1
+	lines=$2
+
+	cleanup_scene
+	N=$((N + 1))
+	INNER="$TEST_TMUX -Lpopup-status-inner-$$-$N -f/dev/null"
+	OUTER="$TEST_TMUX -Lpopup-status-outer-$$-$N -f/dev/null"
+
+	C="sh -c 'i=1; while [ \$i -le 10 ]; do printf \"\\033[%d;1HAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\" \$i; i=\$((i + 1)); done; exec sleep 100'"
+	$INNER new-session -d -s inner -x 40 -y 10 "$C" || exit 1
+	$INNER set-option -g window-size manual || exit 1
+	$INNER set-option -g mouse on || exit 1
+	if [ "$lines" -eq 1 ]; then
+		$INNER set-option -g status on || exit 1
+	else
+		$INNER set-option -g status "$lines" || exit 1
+	fi
+	$INNER set-option -g status-position "$position" || exit 1
+	$INNER set-option -g status-format[0] \
+	    'STATUS-LINE-MARK-01234567890123456789012' || exit 1
+	if [ "$lines" -gt 1 ]; then
+		$INNER set-option -g status-format[1] \
+		    'SECOND-STATUS-MARK-012345678901234567890' || exit 1
+	fi
+	$INNER set-option -g status-interval 0 || exit 1
+
+	$OUTER new-session -d -s outer -x 40 -y 10 'sleep 100' || exit 1
+	$OUTER set-option -g status off || exit 1
+	$OUTER set-option -g window-size manual || exit 1
+	$OUTER respawn-pane -k -t outer:0.0 \
+	    "$TEST_TMUX -Lpopup-status-inner-$$-$N -f/dev/null attach-session -t inner" ||
+	    exit 1
+
+	wait_for_client
+	wait_outer_has STATUS-LINE-MARK
+	$OUTER capture-pane -p -t outer:0.0 >"$BASE" || exit 1
+}
+
+open_popup()
+{
+	y=$1
+	height=$2
+	$INNER display-popup -t "$CLIENT" -x 0 -y "$y" -w 16 -h "$height" -E \
+	    "sh -c 'printf POPUP-MARKER; exec sleep 100'" &
+	POPUP_PID=$!
+	wait_outer_has POPUP-MARKER
+}
+
+if [ "${STATUS_CASE:-all}" != top ]; then
+	# A popup clipped against a one-line bottom status must restore that line.
+	setup bottom 1
+	open_popup 10 3
+	mouse 0 10 8 M
+	mouse 32 11 8 M
+	mouse 32 25 4 M
+	mouse 0 25 4 m
+	wait_rows_restored 10 10
+fi
+
+if [ "${STATUS_CASE:-all}" != bottom ]; then
+	# A popup beginning in a two-line top status also covers the first window
+	# rows. Restore both coordinate spaces after it moves.
+	setup top 2
+	open_popup 1 4
+	mouse 0 10 1 M
+	mouse 32 11 1 M
+	mouse 32 25 7 M
+	mouse 0 25 7 m
+	wait_rows_restored 1 4
+fi
+
+exit 0
--- a/regress/popup-drag-wide-character.sh
+++ b/regress/popup-drag-wide-character.sh
@@ -0,0 +1,126 @@
+#!/bin/sh
+
+# Damage at a popup edge must redraw complete grid characters. Drawing only a
+# wide character's base or padding cell leaves a two-cell hole behind.
+
+PATH=/bin:/usr/bin
+TERM=screen
+LC_ALL=C.UTF-8
+export PATH TERM LC_ALL
+
+[ -z "$TEST_TMUX" ] && TEST_TMUX=$(readlink -f ../tmux)
+
+DIR=$(mktemp -d) || exit 1
+INNER="$TEST_TMUX -Lpopup-wide-inner-$$ -f/dev/null"
+OUTER="$TEST_TMUX -Lpopup-wide-outer-$$ -f/dev/null"
+EMITTER=$DIR/emitter.pl
+BASE=$DIR/base
+CAPTURE=$DIR/capture
+POPUP_PID=
+
+fail()
+{
+	echo "$*" >&2
+	[ -s "$CAPTURE" ] && cat "$CAPTURE" >&2
+	exit 1
+}
+
+cleanup()
+{
+	[ -n "$POPUP_PID" ] && kill "$POPUP_PID" 2>/dev/null
+	$OUTER kill-server 2>/dev/null
+	$INNER kill-server 2>/dev/null
+	rm -rf "$DIR"
+}
+trap cleanup 0 1 15
+
+wait_for_client()
+{
+	i=0
+	while [ "$i" -lt 50 ]; do
+		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_outer_has()
+{
+	marker=$1
+	i=0
+	while [ "$i" -lt 50 ]; do
+		$OUTER capture-pane -p -t outer:0.0 >"$CAPTURE" 2>/dev/null || true
+		grep -q "$marker" "$CAPTURE" && return 0
+		sleep 0.1
+		i=$((i + 1))
+	done
+	fail "outer client did not show $marker"
+}
+
+wait_old_rows_restored()
+{
+	i=0
+	while [ "$i" -lt 50 ]; do
+		$OUTER capture-pane -p -t outer:0.0 >"$CAPTURE" 2>/dev/null || true
+		sed -n '3,5p' "$BASE" >"$DIR/want"
+		sed -n '3,5p' "$CAPTURE" >"$DIR/got"
+		cmp -s "$DIR/want" "$DIR/got" && return 0
+		sleep 0.1
+		i=$((i + 1))
+	done
+	fail "wide characters under the old popup edge were not restored"
+}
+
+mouse()
+{
+	sequence=$(printf '\033[<%s;%s;%s%s' "$1" "$2" "$3" "$4")
+	$OUTER send-keys -t outer:0.0 -l "$sequence" || exit 1
+	sleep 0.1
+}
+
+cat >"$EMITTER" <<'PERL'
+use strict;
+use warnings;
+
+binmode STDOUT, ':encoding(UTF-8)';
+$| = 1;
+for my $row (1 .. 10) {
+	print "\e[$row;1H", chr(0x754c) x 20;
+}
+sleep 100;
+PERL
+
+$INNER new-session -d -s inner -x 40 -y 10 "perl '$EMITTER'" || exit 1
+$INNER set-option -g status off || exit 1
+$INNER set-option -g window-size manual || exit 1
+$INNER set-option -g mouse on || exit 1
+
+$OUTER new-session -d -s outer -x 40 -y 10 'sleep 100' || exit 1
+$OUTER set-option -g status off || exit 1
+$OUTER set-option -g window-size manual || exit 1
+$OUTER set-option -g default-terminal screen-256color || exit 1
+$OUTER respawn-pane -k -t outer:0.0 \
+    "$TEST_TMUX -Lpopup-wide-inner-$$ -f/dev/null attach-session -t inner" ||
+    exit 1
+
+wait_for_client
+wait_outer_has '界界界'
+$OUTER capture-pane -p -t outer:0.0 >"$BASE" || exit 1
+
+$INNER display-popup -t "$CLIENT" -x 5 -y 5 -w 10 -h 3 -E \
+    "sh -c 'printf POPUP; exec sleep 100'" &
+POPUP_PID=$!
+wait_outer_has POPUP
+
+# The first motion starts the drag; the second moves the popup away from its
+# old rectangle. Its odd x coordinate bisects the underlying double-width
+# cells at both edges.
+mouse 0 10 3 M
+mouse 32 11 3 M
+mouse 32 28 7 M
+mouse 0 28 7 m
+wait_old_rows_restored
+
+exit 0
--- a/regress/redraw-damage-only.sh
+++ b/regress/redraw-damage-only.sh
@@ -0,0 +1,112 @@
+#!/bin/sh
+
+# Check a redraw callback which has no accompanying client redraw flags. A
+# wrapped row crossing a panned viewport cannot use the direct tty path.
+
+PATH=/bin:/usr/bin
+TERM=screen
+LC_ALL=C.UTF-8
+export PATH TERM LC_ALL
+
+[ -z "$TEST_TMUX" ] && TEST_TMUX=$(readlink -f ../tmux)
+
+DIR=$(mktemp -d) || exit 1
+INNER="$TEST_TMUX -Ldamage-only-inner-$$ -f/dev/null"
+OUTER="$TEST_TMUX -Ldamage-only-outer-$$ -f/dev/null"
+EMITTER=$DIR/emitter.pl
+TRIGGER=$DIR/trigger
+CAPTURE=$DIR/capture
+
+fail()
+{
+	echo "$*" >&2
+	[ -s "$CAPTURE" ] && cat "$CAPTURE" >&2
+	exit 1
+}
+
+cleanup()
+{
+	$OUTER kill-server 2>/dev/null
+	$INNER kill-server 2>/dev/null
+	rm -rf "$DIR"
+}
+trap cleanup 0 1 15
+
+wait_for_client()
+{
+	i=0
+	while [ "$i" -lt 50 ]; do
+		CLIENT=$($INNER list-clients -F '#{client_name}' 2>/dev/null)
+		[ -n "$CLIENT" ] && return 0
+		sleep 0.1
+		i=$((i + 1))
+	done
+	fail "inner client did not attach"
+}
+
+wait_outer_has()
+{
+	marker=$1
+	i=0
+	while [ "$i" -lt 50 ]; do
+		$OUTER capture-pane -p -t outer:0.0 >"$CAPTURE" 2>/dev/null || true
+		grep -q "$marker" "$CAPTURE" && return 0
+		sleep 0.1
+		i=$((i + 1))
+	done
+	fail "outer client did not show $marker"
+}
+
+wait_inner_has()
+{
+	marker=$1
+	i=0
+	while [ "$i" -lt 50 ]; do
+		$INNER capture-pane -p -t inner:0.0 2>/dev/null |
+		    grep -q "$marker" && return 0
+		sleep 0.1
+		i=$((i + 1))
+	done
+	fail "inner pane did not contain $marker"
+}
+
+cat >"$EMITTER" <<'PERL'
+use strict;
+use warnings;
+
+$| = 1;
+for my $row (1 .. 12) {
+	print "\e[$row;1H", 'o' x 79;
+}
+print "\e[1;1H";
+while (!-e $ENV{TRIGGER}) {
+	select undef, undef, undef, 0.01;
+}
+
+my $second = ('B' x 24) . 'DAMAGE-ONLY' . ('B' x 45);
+print "\e[5;1H", ('A' x 80), $second;
+sleep 100;
+PERL
+
+$INNER new-session -d -s inner -x 80 -y 12 \
+    "TRIGGER='$TRIGGER' perl '$EMITTER'" || exit 1
+$INNER set-option -g status off || exit 1
+$INNER set-option -g window-size manual || exit 1
+
+$OUTER new-session -d -s outer -x 40 -y 12 'sleep 100' || exit 1
+$OUTER set-option -g status off || exit 1
+$OUTER set-option -g window-size manual || exit 1
+$OUTER set-option -g default-terminal screen || exit 1
+$OUTER respawn-pane -k -t outer:0.0 \
+    "$TEST_TMUX -Ldamage-only-inner-$$ -f/dev/null attach-session -t inner" ||
+    exit 1
+
+wait_for_client
+$INNER refresh-client -t "$CLIENT" -R 20 || exit 1
+wait_outer_has oooooooooo
+
+: >"$TRIGGER"
+wait_inner_has DAMAGE-ONLY
+wait_outer_has DAMAGE-ONLY
+
+exit 0
--- a/regress/redraw-multiclient.sh
+++ b/regress/redraw-multiclient.sh
@@ -0,0 +1,186 @@
+#!/bin/sh
+
+# Redraw a moved floating pane on both attached clients viewing the same
+# window. Window redraw work must not be consumed by only one client.
+#
+# Uses ASCII pane borders (rather than the default UTF-8 box-drawing) because
+# this test nests a real tmux client inside another tmux's pane to get a
+# genuine terminal to capture from; that nested-tmux relay has been observed
+# to mis-render a cell that previously held a multi-byte UTF-8 border
+# character being overwritten later by plain content, on the outer instance's
+# own interpretation, independent of anything the inner tmux sends. That is a
+# nested-test-harness artifact, not a real tmux bug - confirmed by replaying
+# the exact same drag sequence against a real terminal (xterm), where it
+# never reproduces. ASCII borders avoid the artifact entirely.
+
+PATH=/bin:/usr/bin
+TERM=screen
+LC_ALL=C.UTF-8
+export PATH TERM LC_ALL
+
+[ -z "$TEST_TMUX" ] && TEST_TMUX=$(readlink -f ../tmux)
+
+DIR=$(mktemp -d) || exit 1
+INNER="$TEST_TMUX -Lredraw-multi-inner-$$ -f/dev/null"
+OUTER="$TEST_TMUX -Lredraw-multi-outer-$$ -f/dev/null"
+CAPTURE=$DIR/capture
+
+fail()
+{
+	echo "$*" >&2
+	[ -s "$CAPTURE" ] && cat "$CAPTURE" >&2
+	exit 1
+}
+
+cleanup()
+{
+	$OUTER kill-server 2>/dev/null
+	$INNER kill-server 2>/dev/null
+	rm -rf "$DIR"
+}
+trap cleanup 0 1 15
+
+wait_for_clients()
+{
+	i=0
+	while [ "$i" -lt 50 ]; do
+		count=$($INNER list-clients 2>/dev/null | wc -l)
+		[ "$count" -eq 2 ] && return 0
+		sleep 0.1
+		i=$((i + 1))
+	done
+	fail "two inner clients did not attach"
+}
+
+wait_outer_has()
+{
+	target=$1
+	marker=$2
+	i=0
+	while [ "$i" -lt 50 ]; do
+		$OUTER capture-pane -p -t "$target" >"$CAPTURE" 2>/dev/null || true
+		grep -q "$marker" "$CAPTURE" && return 0
+		sleep 0.1
+		i=$((i + 1))
+	done
+	fail "outer pane $target did not show $marker"
+}
+
+wait_float_left()
+{
+	comparison=$1
+	limit=$2
+	i=0
+	while [ "$i" -lt 50 ]; do
+		left=$($INNER display-message -p -t "$FLOAT" '#{pane_left}')
+		if [ "$comparison" = gt ] && [ "$left" -gt "$limit" ]; then
+			return 0
+		fi
+		if [ "$comparison" = lt ] && [ "$left" -lt "$limit" ]; then
+			return 0
+		fi
+		sleep 0.1
+		i=$((i + 1))
+	done
+	fail "floating pane did not move"
+}
+
+mouse()
+{
+	sequence=$(printf '\033[<%s;%s;%s%s' "$2" "$3" "$4" "$5")
+	$OUTER send-keys -t "$1" -l "$sequence" || exit 1
+	sleep 0.1
+}
+
+drag_float()
+{
+	target=$1
+	startcol=$2
+	startrow=$3
+	endcol=$4
+	mouse "$target" 0 "$startcol" "$startrow" M
+	mouse "$target" 32 "$endcol" "$startrow" M
+	mouse "$target" 0 "$endcol" "$startrow" m
+}
+
+assert_scene()
+{
+	target=$1
+	base=$2
+	firstcol=$3
+	lastcol=$4
+
+	$OUTER capture-pane -p -t "$target" >"$CAPTURE" || exit 1
+
+	# With ASCII (simple) borders every corner and junction is the same
+	# '+', so one rectangular floating pane always draws exactly 4 of
+	# them; more means a stale frame was left behind somewhere.
+	corners=$(grep -o '+' "$CAPTURE" | wc -l)
+	[ "$corners" -eq 4 ] ||
+	    fail "outer pane $target had $corners floating frames"
+
+	sed -n '6,11p' "$base" | cut -c"$firstcol-$lastcol" >"$DIR/want"
+	sed -n '6,11p' "$CAPTURE" | cut -c"$firstcol-$lastcol" >"$DIR/got"
+	cmp -s "$DIR/want" "$DIR/got" ||
+	    fail "outer pane $target did not restore the old floating area"
+}
+
+C="sh -c 'i=0; while [ \$i -lt 20 ]; do printf \"\\033[%d;1HBG-ROW-%02d-abcdefghijklmnopqrstuvwxyz0123456789\" \$((i + 1)) \$i; i=\$((i + 1)); done; exec sleep 100'"
+
+$INNER new-session -d -s inner -x 60 -y 20 "$C" || exit 1
+$INNER set-option -g status off || exit 1
+$INNER set-option -g window-size manual || exit 1
+$INNER set-option -g mouse on || exit 1
+$INNER set-option -g default-command 'sleep 100' || exit 1
+$INNER set-option -g pane-border-lines simple || exit 1
+
+$OUTER new-session -d -s outer -x 121 -y 20 'sleep 100' || exit 1
+$OUTER set-option -g status off || exit 1
+$OUTER set-option -g window-size manual || exit 1
+$OUTER set-option -g default-terminal screen || exit 1
+$OUTER split-window -h -t outer:0.0 'sleep 100' || exit 1
+
+PANES=$($OUTER list-panes -t outer:0 -F '#{pane_id} #{pane_left}')
+LEFT=$(echo "$PANES" | sort -k2 -n | head -1 | cut -d' ' -f1)
+RIGHT=$(echo "$PANES" | sort -k2 -n | tail -1 | cut -d' ' -f1)
+[ -n "$LEFT" ] && [ -n "$RIGHT" ] || fail "could not find outer panes"
+
+$OUTER respawn-pane -k -t "$LEFT" \
+    "$TEST_TMUX -Lredraw-multi-inner-$$ -f/dev/null attach-session -t inner" ||
+    exit 1
+$OUTER respawn-pane -k -t "$RIGHT" \
+    "$TEST_TMUX -Lredraw-multi-inner-$$ -f/dev/null attach-session -t inner" ||
+    exit 1
+
+wait_for_clients
+wait_outer_has "$LEFT" BG-ROW-19
+wait_outer_has "$RIGHT" BG-ROW-19
+$OUTER capture-pane -p -t "$LEFT" >"$DIR/base-left" || exit 1
+$OUTER capture-pane -p -t "$RIGHT" >"$DIR/base-right" || exit 1
+
+FLOAT=$($INNER new-pane -dPF '#{pane_id}' -x 16 -y 5 -X 5 -Y 5) ||
+    fail "could not create floating pane"
+wait_outer_has "$LEFT" '+'
+wait_outer_has "$RIGHT" '+'
+
+FTOP=$($INNER display-message -p -t "$FLOAT" '#{pane_top}')
+FLEFT=$($INNER display-message -p -t "$FLOAT" '#{pane_left}')
+FWIDTH=$($INNER display-message -p -t "$FLOAT" '#{pane_width}')
+GRABCOL=$((FLEFT + FWIDTH / 2 + 1))
+
+# Move right through one client and require both clients to restore the old
+# left-hand footprint.
+drag_float "$LEFT" "$GRABCOL" "$FTOP" $((GRABCOL + 30))
+wait_float_left gt 30
+assert_scene "$LEFT" "$DIR/base-left" 1 20
+assert_scene "$RIGHT" "$DIR/base-right" 1 20
+
+# Move back through the other client and check the old right-hand footprint.
+FLEFT=$($INNER display-message -p -t "$FLOAT" '#{pane_left}')
+GRABCOL=$((FLEFT + FWIDTH / 2 + 1))
+drag_float "$RIGHT" "$GRABCOL" "$FTOP" $((GRABCOL - 30))
+wait_float_left lt 10
+assert_scene "$LEFT" "$DIR/base-left" 35 60
+assert_scene "$RIGHT" "$DIR/base-right" 35 60
+
+exit 0
--- a/regress/redraw-screen-write.sh
+++ b/regress/redraw-screen-write.sh
@@ -0,0 +1,208 @@
+#!/bin/sh
+
+# Check that full and region screen-write fallbacks update an attached client,
+# not only tmux's internal pane grid.
+
+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
+EMITTER=$DIR/emitter.pl
+CAPTURE=$DIR/capture
+INNER=
+OUTER=
+N=0
+
+fail()
+{
+	echo "$*" >&2
+	[ -s "$CAPTURE" ] && cat "$CAPTURE" >&2
+	exit 1
+}
+
+cleanup()
+{
+	[ -n "$OUTER" ] && $OUTER kill-server 2>/dev/null
+	[ -n "$INNER" ] && $INNER kill-server 2>/dev/null
+	rm -rf "$DIR"
+}
+trap cleanup 0 1 15
+
+wait_outer_has()
+{
+	marker=$1
+	i=0
+	while [ "$i" -lt 50 ]; do
+		$OUTER capture-pane -p -t outer:0.0 >"$CAPTURE" 2>/dev/null || true
+		grep -q "$marker" "$CAPTURE" && return 0
+		sleep 0.1
+		i=$((i + 1))
+	done
+	fail "outer client did not show $marker"
+}
+
+wait_outer_lacks()
+{
+	marker=$1
+	i=0
+	while [ "$i" -lt 50 ]; do
+		$OUTER capture-pane -p -t outer:0.0 >"$CAPTURE" 2>/dev/null || true
+		grep -q "$marker" "$CAPTURE" || return 0
+		sleep 0.1
+		i=$((i + 1))
+	done
+	fail "outer client still showed $marker"
+}
+
+wait_inner_has()
+{
+	marker=$1
+	i=0
+	while [ "$i" -lt 50 ]; do
+		$INNER capture-pane -p -t inner:0.0 2>/dev/null |
+		    grep -q "$marker" && return 0
+		sleep 0.1
+		i=$((i + 1))
+	done
+	fail "inner pane did not contain $marker"
+}
+
+wait_inner_lacks()
+{
+	marker=$1
+	i=0
+	while [ "$i" -lt 50 ]; do
+		$INNER capture-pane -p -t inner:0.0 >"$CAPTURE" 2>/dev/null || true
+		grep -q "$marker" "$CAPTURE" || return 0
+		sleep 0.1
+		i=$((i + 1))
+	done
+	fail "inner pane still contained $marker"
+}
+
+setup()
+{
+	mode=$1
+	[ -n "$OUTER" ] && $OUTER kill-server 2>/dev/null
+	[ -n "$INNER" ] && $INNER kill-server 2>/dev/null
+	N=$((N + 1))
+	INNER="$TEST_TMUX -Lredraw-write-inner-$$-$N -f/dev/null"
+	OUTER="$TEST_TMUX -Lredraw-write-outer-$$-$N -f/dev/null"
+
+	$INNER new-session -d -s inner -x 40 -y 12 \
+	    "MODE=$mode READY='$DIR/ready-$N' TRIGGER='$DIR/trigger-$N' perl '$EMITTER'" ||
+	    exit 1
+	$INNER set-option -g status off || exit 1
+	$INNER set-option -g window-size manual || exit 1
+
+	$OUTER new-session -d -s outer -x 40 -y 12 'sleep 100' || exit 1
+	$OUTER set-option -g status off || exit 1
+	$OUTER set-option -g window-size manual || exit 1
+	$OUTER set-option -g default-terminal screen || exit 1
+	$OUTER respawn-pane -k -t outer:0.0 \
+	    "$TEST_TMUX -Lredraw-write-inner-$$-$N -f/dev/null attach-session -t inner" ||
+	    exit 1
+}
+
+trigger()
+{
+	: >"$DIR/trigger-$N-${1:-1}"
+}
+
+cat >"$EMITTER" <<'PERL'
+use strict;
+use warnings;
+
+$| = 1;
+my $mode = $ENV{MODE};
+my $ready = $ENV{READY};
+my $trigger = $ENV{TRIGGER};
+
+sub fill_screen {
+	my ($prefix) = @_;
+	print "\e[2J\e[H";
+	for my $row (0 .. 11) {
+		printf "\e[%d;1H%s-ROW-%02d", $row + 1, $prefix, $row;
+	}
+}
+
+if ($mode eq 'ris') {
+	fill_screen('RIS');
+} elsif ($mode eq 'alternate') {
+	fill_screen('BASE');
+} elsif ($mode eq 'scroll') {
+	fill_screen('SCROLL');
+} else {
+	die "unknown mode $mode\n";
+}
+
+open my $fh, '>', $ready or die "$ready: $!\n";
+close $fh;
+while (!-e "$trigger-1") {
+	select undef, undef, undef, 0.01;
+}
+
+if ($mode eq 'ris') {
+	print "\ec";
+} elsif ($mode eq 'alternate') {
+	print "\e[?1049h";
+	fill_screen('ALT');
+	while (!-e "$trigger-2") {
+		select undef, undef, undef, 0.01;
+	}
+	print "\e[?1049l";
+} else {
+	print "\e[12;1H\r\nSCROLL-NEW";
+}
+sleep 100;
+PERL
+
+# RIS clears the complete screen. The source pane and attached client must both
+# lose every old row.
+setup ris
+wait_outer_has RIS-ROW-11
+trigger
+wait_inner_lacks RIS-ROW
+wait_outer_lacks RIS-ROW
+
+# Leaving the alternate screen restores every row of the base screen.
+setup alternate
+wait_outer_has BASE-ROW-11
+trigger
+wait_inner_has ALT-ROW-11
+wait_outer_has ALT-ROW-11
+wait_outer_lacks BASE-ROW
+trigger 2
+wait_inner_has BASE-ROW-11
+wait_outer_has BASE-ROW-11
+wait_outer_lacks ALT-ROW
+
+# Scrolling a pane which is narrower than the terminal redraws its complete
+# region. Check the physical client row by row after the source grid shifts.
+setup scroll
+$INNER split-window -h -t inner:0 'sleep 100' || exit 1
+wait_outer_has SCROLL-ROW-11
+trigger
+wait_inner_has SCROLL-NEW
+wait_outer_has SCROLL-NEW
+row=1
+while [ "$row" -le 11 ]; do
+	expected=$(printf 'SCROLL-ROW-%02d' "$row")
+	actual=$(sed -n "${row}p" "$CAPTURE")
+	case "$actual" in
+	"$expected"*) ;;
+	*) fail "outer row $row was not redrawn as $expected" ;;
+	esac
+	row=$((row + 1))
+done
+actual=$(sed -n '12p' "$CAPTURE")
+case "$actual" in
+SCROLL-NEW*) ;;
+*) fail "outer bottom row was not redrawn as SCROLL-NEW" ;;
+esac
+
+exit 0
--- a/regress/screen-redraw-floating.sh
+++ b/regress/screen-redraw-floating.sh
@@ -107,12 +107,6 @@ $TMUX2 new-pane -x28 -y8 -X4 -Y1 -B double \
 	"sh -c 'printf FLOAT; exec sleep 100'" || exit 1
 compare floating-border-double

-# Larger floating pane with rounded border lines.
-new_scene 40 12
-$TMUX2 new-pane -x28 -y8 -X4 -Y1 -B rounded \
-	"sh -c 'printf FLOAT; exec sleep 100'" || exit 1
-compare floating-border-rounded
-
 # Floating pane with no border lines: redraw_mark_pane_borders returns early so
 # the float has no border at all, only its (clipped) content over the base pane.
 new_scene 40 12
--- a/regress/screen-redraw-results/floating-border-rounded.result
+++ b/regress/screen-redraw-results/floating-border-rounded.result
@@ -1,12 +0,0 @@
-base
-    ╭──────────────────────────╮
-    │FLOAT                     │
-    │                          │
-    │                          │
-    │                          │
-    │                          │
-    │                          │
-    ╰──────────────────────────╯
-
-
-
--- a/regress/switch-client-redraw.sh
+++ b/regress/switch-client-redraw.sh
@@ -0,0 +1,81 @@
+#!/bin/sh
+
+# Switching windows in the same session must redraw the attached client. The
+# session object is shared, so its current winlink cannot be compared after it
+# has already been changed.
+
+PATH=/bin:/usr/bin
+TERM=screen
+LC_ALL=C.UTF-8
+export PATH TERM LC_ALL
+
+[ -z "$TEST_TMUX" ] && TEST_TMUX=$(readlink -f ../tmux)
+
+DIR=$(mktemp -d) || exit 1
+INNER="$TEST_TMUX -Lswitch-redraw-inner-$$ -f/dev/null"
+OUTER="$TEST_TMUX -Lswitch-redraw-outer-$$ -f/dev/null"
+CAPTURE=$DIR/capture
+
+fail()
+{
+	echo "$*" >&2
+	[ -s "$CAPTURE" ] && cat "$CAPTURE" >&2
+	exit 1
+}
+
+cleanup()
+{
+	$OUTER kill-server 2>/dev/null
+	$INNER kill-server 2>/dev/null
+	rm -rf "$DIR"
+}
+trap cleanup 0 1 15
+
+wait_for_client()
+{
+	i=0
+	while [ "$i" -lt 50 ]; do
+		CLIENT=$($INNER list-clients -F '#{client_name}' 2>/dev/null)
+		[ -n "$CLIENT" ] && return 0
+		sleep 0.1
+		i=$((i + 1))
+	done
+	fail "inner client did not attach"
+}
+
+wait_outer_has()
+{
+	marker=$1
+	i=0
+	while [ "$i" -lt 50 ]; do
+		$OUTER capture-pane -p -t outer:0.0 >"$CAPTURE" 2>/dev/null || true
+		grep -q "$marker" "$CAPTURE" && return 0
+		sleep 0.1
+		i=$((i + 1))
+	done
+	fail "outer client did not show $marker"
+}
+
+$INNER new-session -d -s inner -x 40 -y 8 \
+    "printf '\033[2J\033[HA-WINDOW'; exec sleep 100" || exit 1
+$INNER new-window -d -t inner:1 \
+    "printf '\033[2J\033[HB-WINDOW'; exec sleep 100" || exit 1
+$INNER set-option -g status off || exit 1
+$INNER set-option -g window-size manual || exit 1
+
+$OUTER new-session -d -s outer -x 40 -y 8 'sleep 100' || exit 1
+$OUTER set-option -g status off || exit 1
+$OUTER set-option -g window-size manual || exit 1
+$OUTER respawn-pane -k -t outer:0.0 \
+    "$TEST_TMUX -Lswitch-redraw-inner-$$ -f/dev/null attach-session -t inner:0" ||
+    exit 1
+
+wait_for_client
+wait_outer_has A-WINDOW
+
+$INNER switch-client -c "$CLIENT" -t inner:1.0 || exit 1
+[ "$($INNER display-message -p -t inner '#{window_index}')" -eq 1 ] ||
+    fail "server did not select window 1"
+wait_outer_has B-WINDOW
+
+exit 0
--- a/screen-redraw.c
+++ b/screen-redraw.c
@@ -205,6 +205,22 @@ struct redraw_scene {
 	u_int			 oy;
 };

+/* A single damaged window-coordinate rectangle. */
+struct redraw_damage {
+	u_int			 x;
+	u_int			 y;
+	u_int			 sx;
+	u_int			 sy;
+
+	TAILQ_ENTRY(redraw_damage) entry;
+};
+
+/*
+ * Cap on the number of pending damage rectangles per window before they are
+ * collapsed into a single rectangle covering their union.
+ */
+#define REDRAW_DAMAGE_MAX 16
+
 /* Cell for building the scene. */
 struct redraw_build_cell {
 	struct redraw_span_data	 data;
@@ -1057,6 +1073,13 @@ redraw_free_scene(struct redraw_scene *scene)
 	free(scene);
 }

+/* Does a client's cached scene show this window? */
+int
+redraw_client_has_window(struct client *c, struct window *w)
+{
+	return (c->redraw_scene != NULL && c->redraw_scene->w == w);
+}
+
 /* Mark a window's cached redraw scenes as out of date. */
 void
 redraw_invalidate_scene(struct window *w)
@@ -1064,6 +1087,114 @@ redraw_invalidate_scene(struct window *w)
 	w->redraw_scene_generation++;
 }

+/* Free all pending damage for a window. */
+void
+redraw_free_damage(struct window *w)
+{
+	struct redraw_damage	*rd, *rd1;
+
+	TAILQ_FOREACH_SAFE(rd, &w->damage, entry, rd1) {
+		TAILQ_REMOVE(&w->damage, rd, entry);
+		free(rd);
+	}
+	w->damage_count = 0;
+}
+
+/* Collapse all pending damage for a window into one rectangle - its union. */
+static void
+redraw_collapse_damage(struct window *w)
+{
+	struct redraw_damage	*rd, *rd1, *first;
+	u_int			 x0, y0, x1, y1;
+
+	first = TAILQ_FIRST(&w->damage);
+	if (first == NULL)
+		return;
+	x0 = first->x;
+	y0 = first->y;
+	x1 = first->x + first->sx;
+	y1 = first->y + first->sy;
+
+	TAILQ_FOREACH_SAFE(rd, &w->damage, entry, rd1) {
+		if (rd->x < x0)
+			x0 = rd->x;
+		if (rd->y < y0)
+			y0 = rd->y;
+		if (rd->x + rd->sx > x1)
+			x1 = rd->x + rd->sx;
+		if (rd->y + rd->sy > y1)
+			y1 = rd->y + rd->sy;
+		if (rd != first) {
+			TAILQ_REMOVE(&w->damage, rd, entry);
+			free(rd);
+		}
+	}
+
+	first->x = x0;
+	first->y = y0;
+	first->sx = x1 - x0;
+	first->sy = y1 - y0;
+	w->damage_count = 1;
+}
+
+/*
+ * Record a damaged window-coordinate rectangle. Clips it to the window,
+ * merges it with an existing rectangle where doing so does not make the
+ * result substantially larger than the two combined, and collapses the
+ * whole list to its union once it grows past a modest cap.
+ *
+ * This only records damage - nothing consumes it yet.
+ */
+void
+redraw_damage_window(struct window *w, u_int x, u_int y, u_int sx, u_int sy)
+{
+	struct redraw_damage	*rd;
+	u_int			 x0, y0, x1, y1, area, union_area;
+
+	if (x >= w->sx || y >= w->sy)
+		return;
+	if (x + sx > w->sx)
+		sx = w->sx - x;
+	if (y + sy > w->sy)
+		sy = w->sy - y;
+	if (sx == 0 || sy == 0)
+		return;
+
+	TAILQ_FOREACH(rd, &w->damage, entry) {
+		/* Skip unless overlapping or directly adjacent. */
+		if (x > rd->x + rd->sx || rd->x > x + sx ||
+		    y > rd->y + rd->sy || rd->y > y + sy)
+			continue;
+
+		x0 = (x < rd->x) ? x : rd->x;
+		y0 = (y < rd->y) ? y : rd->y;
+		x1 = (x + sx > rd->x + rd->sx) ? x + sx : rd->x + rd->sx;
+		y1 = (y + sy > rd->y + rd->sy) ? y + sy : rd->y + rd->sy;
+
+		area = sx * sy + rd->sx * rd->sy;
+		union_area = (x1 - x0) * (y1 - y0);
+		if (union_area > 2 * area)
+			continue;
+
+		rd->x = x0;
+		rd->y = y0;
+		rd->sx = x1 - x0;
+		rd->sy = y1 - y0;
+		return;
+	}
+
+	rd = xcalloc(1, sizeof *rd);
+	rd->x = x;
+	rd->y = y;
+	rd->sx = sx;
+	rd->sy = sy;
+	TAILQ_INSERT_TAIL(&w->damage, rd, entry);
+	w->damage_count++;
+
+	if (w->damage_count > REDRAW_DAMAGE_MAX)
+		redraw_collapse_damage(w);
+}
+
 /* Mark all cached redraw scenes as out of date. */
 void
 redraw_invalidate_all_scenes(void)
@@ -1376,10 +1507,15 @@ redraw_draw_menu_span(struct redraw_draw_ctx *dctx,
 	tty_draw_line(tty, s, px, span->data.m.py, n, x, y, NULL);
 }

-/* Draw a span. */
+/*
+ * Draw a span, restricted to [clip_x, clip_x + clip_n) - a caller drawing
+ * the whole span passes the span's own x/width here; a caller drawing only
+ * a damaged sub-range passes that range instead. Overlay clipping (menus,
+ * popups) is then applied on top of this, exactly as before.
+ */
 static void
 redraw_draw_span(struct redraw_draw_ctx *dctx, struct redraw_span *span,
-    u_int y)
+    u_int y, u_int clip_x, u_int clip_n)
 {
 	struct redraw_scene	*scene = dctx->scene;
 	struct redraw_span_data	*data = &span->data;
@@ -1393,7 +1529,7 @@ redraw_draw_span(struct redraw_draw_ctx *dctx, struct redraw_span *span,
 	if (type == REDRAW_SPAN_STATUS && ~data->st.wp->flags & PANE_NEWSTATUS)
 		return;

-	r = tty_check_overlay_range(tty, span->x, y, span->width);
+	r = tty_check_overlay_range(tty, clip_x, y, clip_n);
 	for (i = 0; i < r->used; i++) {
 		rr = &r->ranges[i];
 		if (rr->nx == 0)
@@ -1453,15 +1589,19 @@ redraw_draw_pane_lines(struct redraw_draw_ctx *dctx, struct window_pane *wp,
 		if (flags & REDRAW_PANE) {
 			spans = &line->spans[REDRAW_SPAN_PANE];
 			TAILQ_FOREACH(span, spans, entry) {
-				if (span->data.p.wp == wp)
-					redraw_draw_span(dctx, span, cy);
+				if (span->data.p.wp == wp) {
+					redraw_draw_span(dctx, span, cy,
+					    span->x, span->width);
+				}
 			}
 		}
 		if (flags & REDRAW_PANE_SCROLLBAR) {
 			spans = &line->spans[REDRAW_SPAN_SCROLLBAR];
 			TAILQ_FOREACH(span, spans, entry) {
-				if (span->data.sb.wp == wp)
-					redraw_draw_span(dctx, span, cy);
+				if (span->data.sb.wp == wp) {
+					redraw_draw_span(dctx, span, cy,
+					    span->x, span->width);
+				}
 			}
 		}
 	}
@@ -1519,8 +1659,10 @@ redraw_draw_lines(struct redraw_draw_ctx *dctx, int flags)
 				}
 			}
 			spans = &line->spans[type];
-			TAILQ_FOREACH(span, spans, entry)
-				redraw_draw_span(dctx, span, cy);
+			TAILQ_FOREACH(span, spans, entry) {
+				redraw_draw_span(dctx, span, cy, span->x,
+				    span->width);
+			}
 		}
 	}
 }
@@ -1540,8 +1682,10 @@ redraw_draw_menu_lines(struct redraw_draw_ctx *dctx)
 			cy = dctx->status_lines + y;
 		else
 			cy = y;
-		TAILQ_FOREACH(span, &line->spans[REDRAW_SPAN_MENU], entry)
-			redraw_draw_span(dctx, span, cy);
+		TAILQ_FOREACH(span, &line->spans[REDRAW_SPAN_MENU], entry) {
+			redraw_draw_span(dctx, span, cy, span->x,
+			    span->width);
+		}
 	}
 }

@@ -1621,6 +1765,24 @@ redraw_set_draw_context(struct redraw_draw_ctx *dctx,
 		dctx->flags |= REDRAW_ISOLATES;
 }

+/* Build a pane prompt into a one-line screen. */
+static void
+redraw_make_pane_prompt(struct window_pane *wp, struct screen *screen)
+{
+	struct screen_write_ctx	 ctx;
+	struct prompt_draw_data	 pdd;
+
+	screen_init(screen, wp->sx, 1, 0);
+	screen_write_start(&ctx, screen);
+	pdd.ctx = &ctx;
+	pdd.cursor_x = &wp->prompt_cx;
+	pdd.area_x = 0;
+	pdd.area_width = wp->sx;
+	pdd.prompt_line = 0;
+	prompt_draw(wp->prompt, &pdd);
+	screen_write_stop(&ctx);
+}
+
 /* Draw a pane's prompt over its content. */
 static void
 redraw_draw_pane_prompt(struct redraw_draw_ctx *dctx, struct window_pane *wp)
@@ -1629,8 +1791,6 @@ redraw_draw_pane_prompt(struct redraw_draw_ctx *dctx, struct window_pane *wp)
 	struct client		*c = scene->c;
 	struct tty		*tty = &c->tty;
 	struct screen		 screen;
-	struct screen_write_ctx	 ctx;
-	struct prompt_draw_data	 pdd;
 	int			 ox = scene->ox, oy = scene->oy;
 	int			 sx = scene->sx, sy = scene->sy;
 	int			 line, cy, px, offset, width, wy;
@@ -1663,16 +1823,7 @@ redraw_draw_pane_prompt(struct redraw_draw_ctx *dctx, struct window_pane *wp)
 	if (px + width > sx)
 		width = sx - px;

-	screen_init(&screen, wp->sx, 1, 0);
-	screen_write_start(&ctx, &screen);
-	pdd.ctx = &ctx;
-	pdd.cursor_x = &wp->prompt_cx;
-	pdd.area_x = 0;
-	pdd.area_width = wp->sx;
-	pdd.prompt_line = 0;
-	prompt_draw(wp->prompt, &pdd);
-	screen_write_stop(&ctx);
-
+	redraw_make_pane_prompt(wp, &screen);
 	tty_draw_line(tty, &screen, 0, offset, width, px, cy, NULL);
 	screen_free(&screen);
 }
@@ -1704,7 +1855,8 @@ redraw_draw(struct client *c, struct window_pane *wp, int flags)
 			redraw = status_prompt_redraw(c);
 		else
 			redraw = status_redraw(c);
-		if (!redraw && !REDRAW_IS_ALL(flags)) {
+		if (!redraw && (~c->flags & CLIENT_REDRAWSTATUSALWAYS) &&
+		    !REDRAW_IS_ALL(flags)) {
 			flags &= ~REDRAW_STATUS;
 			if (flags == 0)
 				return;
@@ -1875,7 +2027,7 @@ redraw_screen(struct client *c)
 	} else {
 		if (c->flags & CLIENT_REDRAWBORDERS)
 			flags |= (REDRAW_PANE_BORDER|REDRAW_PANE_STATUS);
-		if (c->flags & CLIENT_REDRAWSTATUS)
+		if (c->flags & (CLIENT_REDRAWSTATUS|CLIENT_REDRAWSTATUSALWAYS))
 			flags |= (REDRAW_STATUS|REDRAW_PANE_STATUS);
 		if (c->flags & CLIENT_REDRAWOVERLAY)
 			flags |= REDRAW_OVERLAY;
@@ -1903,3 +2055,190 @@ redraw_pane_scrollbar(struct client *c, struct window_pane *wp)
 {
 	redraw_draw(c, wp, REDRAW_PANE_SCROLLBAR);
 }
+
+/*
+ * A REDRAW_SPAN_STATUS span within a damaged rectangle needs its content
+ * rebuilt and force-drawn regardless of whether that content has logically
+ * changed. window_make_pane_status()'s grid_compare() only tells us
+ * whether the *content* changed, not whether the physical cells were
+ * disturbed by something else (e.g. a floating pane sliding across this
+ * row) - and being inside a damage rectangle already proves that happened.
+ * Without this, redraw_draw_span() silently skips REDRAW_SPAN_STATUS spans
+ * whenever PANE_NEWSTATUS is not set, leaving a pane's border-status title
+ * blank until some unrelated redraw happens to touch it (e.g. a focus
+ * change or window resize).
+ */
+static void
+redraw_damage_refresh_status(struct redraw_draw_ctx *dctx,
+    struct window_pane *wp)
+{
+	struct redraw_span	*first;
+	u_int			 width;
+
+	if (wp->flags & PANE_NEWSTATUS)
+		return;
+	width = redraw_pane_status_width(dctx, wp, &first);
+	if (width == 0)
+		return;
+	window_make_pane_status(wp, dctx->scene->c, width, first);
+	wp->flags |= PANE_NEWSTATUS;
+}
+
+/*
+ * Grow a clipped span range by one cell on either edge that isn't already at
+ * the span's own boundary. A clip edge that lands mid-character (this is a
+ * damage rectangle, so its edges are geometric and have no idea what's in
+ * the grid) may be sitting on the second, padding half of a wide character
+ * whose first half falls just outside the requested range - growing by one
+ * cell is always enough to pull the whole character back in, since no grid
+ * cell is ever wider than two columns, and clamping to the span's own x and
+ * width keeps this from bleeding into a neighbouring span.
+ */
+static void
+redraw_damage_grow_span_clip(struct redraw_span *span, u_int *xp, u_int *endp)
+{
+	if (*xp > span->x)
+		(*xp)--;
+	if (*endp < span->x + span->width)
+		(*endp)++;
+}
+
+/* Recompose a pane's prompt over a damaged section of its display row. */
+static void
+redraw_damage_draw_pane_prompt(struct redraw_draw_ctx *dctx,
+    struct redraw_span *span, u_int y, u_int x, u_int n)
+{
+	struct redraw_scene	*scene = dctx->scene;
+	struct window_pane	*wp = span->data.p.wp;
+	struct tty		*tty = &scene->c->tty;
+	struct visible_ranges	*r;
+	struct visible_range	*rr;
+	struct screen		 screen;
+	u_int			 i, px, width, prompt_y;
+
+	if (wp->prompt == NULL || wp->sx == 0 || wp->sy == 0)
+		return;
+	if (dctx->flags & REDRAW_STATUS_TOP)
+		prompt_y = 0;
+	else
+		prompt_y = wp->sy - 1;
+	if (span->data.p.py != prompt_y)
+		return;
+
+	redraw_make_pane_prompt(wp, &screen);
+	r = tty_check_overlay_range(tty, x, y, n);
+	for (i = 0; i < r->used; i++) {
+		rr = &r->ranges[i];
+		if (rr->nx == 0)
+			continue;
+		px = span->data.p.px + (rr->px - span->x);
+		if (px >= screen_size_x(&screen))
+			continue;
+		width = rr->nx;
+		if (width > screen_size_x(&screen) - px)
+			width = screen_size_x(&screen) - px;
+		tty_draw_line(tty, &screen, px, 0, width, rr->px, y, NULL);
+	}
+	screen_free(&screen);
+}
+
+/*
+ * Compose exactly the cells within a damaged rectangle (already in this
+ * client's own scene coordinates), rather than a whole pane. For each row
+ * in range, every span of every type whose x-range intersects the
+ * rectangle is drawn restricted to just the intersected sub-range.
+ */
+static void
+redraw_draw_damage_rect(struct redraw_draw_ctx *dctx, u_int x, u_int y,
+    u_int sx, u_int sy)
+{
+	struct redraw_scene	*scene = dctx->scene;
+	struct redraw_line	*line;
+	struct redraw_spans	*spans;
+	struct redraw_span	*span;
+	u_int			 cy, yy, clip_x, clip_end, type;
+
+	if (x >= scene->sx || y >= scene->sy)
+		return;
+	if (x + sx > scene->sx)
+		sx = scene->sx - x;
+	if (y + sy > scene->sy)
+		sy = scene->sy - y;
+	if (sx == 0 || sy == 0)
+		return;
+
+	for (yy = y; yy < y + sy; yy++) {
+		line = &scene->lines[yy];
+		if (dctx->flags & REDRAW_STATUS_TOP)
+			cy = dctx->status_lines + yy;
+		else
+			cy = yy;
+		for (type = 0; type < REDRAW_SPAN_TYPES; type++) {
+			spans = &line->spans[type];
+			TAILQ_FOREACH(span, spans, entry) {
+				clip_x = (span->x > x) ? span->x : x;
+				clip_end = (span->x + span->width < x + sx) ?
+				    span->x + span->width : x + sx;
+				if (clip_end <= clip_x)
+					continue;
+				if (type == REDRAW_SPAN_STATUS) {
+					redraw_damage_refresh_status(dctx,
+					    span->data.st.wp);
+				}
+				redraw_damage_grow_span_clip(span, &clip_x,
+				    &clip_end);
+				redraw_draw_span(dctx, span, cy, clip_x,
+				    clip_end - clip_x);
+				if (type == REDRAW_SPAN_PANE) {
+					redraw_damage_draw_pane_prompt(dctx,
+					    span, cy, clip_x,
+					    clip_end - clip_x);
+				}
+			}
+		}
+	}
+}
+
+/*
+ * Consume a client's window's pending damage by composing exactly the
+ * damaged cells, after clipping each rectangle to what this client can see
+ * and translating it into this client's own scene coordinates.
+ *
+ * Unlike redraw_pane(), this does not redraw a whole pane's worth of cells
+ * for a small disturbance - only the cells within the (clipped) rectangle
+ * are touched, via redraw_draw_damage_rect().
+ */
+void
+redraw_client_damage(struct client *c)
+{
+	struct window		*w = c->session->curw->window;
+	struct redraw_scene	*scene;
+	struct redraw_draw_ctx	 dctx;
+	struct redraw_damage	*rd;
+	u_int			 ox, oy, sx, sy, x0, y0, x1, y1;
+
+	if (TAILQ_EMPTY(&w->damage))
+		return;
+
+	scene = redraw_get_scene(c);
+	if (scene == NULL)
+		return;
+	redraw_set_draw_context(&dctx, scene);
+	redraw_get_window_offset(c, &ox, &oy, &sx, &sy);
+
+	tty_sync_start(&c->tty);
+	tty_update_mode(&c->tty, c->tty.mode & ~CURSOR_MODES, NULL);
+
+	TAILQ_FOREACH(rd, &w->damage, entry) {
+		x0 = (rd->x > ox) ? rd->x : ox;
+		y0 = (rd->y > oy) ? rd->y : oy;
+		x1 = (rd->x + rd->sx < ox + sx) ? rd->x + rd->sx : ox + sx;
+		y1 = (rd->y + rd->sy < oy + sy) ? rd->y + rd->sy : oy + sy;
+		if (x0 >= x1 || y0 >= y1)
+			continue;
+		log_debug("%s: %s composing damage %u,%u %ux%u", __func__,
+		    c->name, x0 - ox, y0 - oy, x1 - x0, y1 - y0);
+		redraw_draw_damage_rect(&dctx, x0 - ox, y0 - oy, x1 - x0,
+		    y1 - y0);
+	}
+}
--- a/screen-write.c
+++ b/screen-write.c
@@ -120,14 +120,20 @@ screen_write_set_cursor(struct screen_write_ctx *ctx, int cx, int cy)
 		evtimer_add(&w->offset_timer, &tv);
 }

-/* Do a full redraw. */
+/*
+ * Called when a write could not be applied directly to the terminal and
+ * needs a redraw instead. Report damage for the requested rows. wp->yoff is
+ * already adjusted past any top pane-border-status row, so wp->yoff + py is
+ * the correct window-coordinate row.
+ */
 static void
-screen_write_redraw_cb(const struct tty_ctx *ttyctx)
+screen_write_redraw_cb(const struct tty_ctx *ttyctx, u_int py, u_int ny)
 {
 	struct window_pane	*wp = ttyctx->arg;

-	if (wp != NULL)
-		wp->flags |= PANE_REDRAW;
+	if (wp == NULL)
+		return;
+	redraw_damage_window(wp->window, wp->xoff, wp->yoff + py, wp->sx, ny);
 }

 /* Update context for client. */
@@ -2155,7 +2161,7 @@ screen_write_fullredraw(struct screen_write_ctx *ctx)

 	screen_write_initctx(ctx, &ttyctx, 1, 0);
 	if (ttyctx.redraw_cb != NULL)
-		ttyctx.redraw_cb(&ttyctx);
+		ttyctx.redraw_cb(&ttyctx, 0, ttyctx.sy);
 }

 /* Trim collected items. */
@@ -3175,7 +3181,7 @@ screen_write_alternateon(struct screen_write_ctx *ctx, struct grid_cell *gc,

 	screen_write_initctx(ctx, &ttyctx, 1, 0);
 	if (ttyctx.redraw_cb != NULL)
-		ttyctx.redraw_cb(&ttyctx);
+		ttyctx.redraw_cb(&ttyctx, 0, ttyctx.sy);
 }

 /* Turn alternate screen off. */
@@ -3200,5 +3206,5 @@ screen_write_alternateoff(struct screen_write_ctx *ctx, struct grid_cell *gc,

 	screen_write_initctx(ctx, &ttyctx, 1, 0);
 	if (ttyctx.redraw_cb != NULL)
-		ttyctx.redraw_cb(&ttyctx);
+		ttyctx.redraw_cb(&ttyctx, 0, ttyctx.sy);
 }
--- a/server-client.c
+++ b/server-client.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: server-client.c,v 1.512 2026/09/10 11:02:18 nicm Exp $ */
+/* $OpenBSD: server-client.c,v 1.511 2026/09/08 10:20:08 nicm Exp $ */

 /*
 * Copyright (c) 2009 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -473,7 +473,33 @@ server_client_set_session(struct client *c, struct session *s)
 		tty_update_client_offset(c);
 		status_timer_start(c);
 		server_client_fire_session_changed(c, old);
-		server_redraw_client(c);
+
+		/*
+		 * A full redraw is only needed if the client's session or
+		 * current window actually changed - not if this merely
+		 * confirmed the client is still looking at the same window
+		 * (as happens when switch-client -t targets a pane in the
+		 * already-current window, e.g. clicking a pane name in a
+		 * second #{P:} status line: the default MouseDown1Status
+		 * binding resolves that click to switch-client -t=, which
+		 * reaches here regardless of whether anything besides the
+		 * active pane changed). Redrawing unconditionally here
+		 * forced a full window redraw for what should have been
+		 * just an active-pane change, already handled narrowly by
+		 * window_set_active_pane() and window_redraw_active_switch()
+		 * before this is reached.
+		 *
+		 * old and s may be the same session object, whose curw was
+		 * already updated to the new window before this function was
+		 * called - old->curw and s->curw would then read the same,
+		 * already-current value, so comparing them can never detect
+		 * a same-session window change. Compare against the client's
+		 * own cached scene instead, which only reflects what it has
+		 * actually drawn.
+		 */
+		if (old == NULL || old != s ||
+		    !redraw_client_has_window(c, s->curw->window))
+			server_redraw_client(c);
 	}

 	server_check_unattached();
@@ -1391,19 +1417,15 @@ server_client_repeat_time(struct client *c, struct key_binding *bd)
 	return (repeat);
 }

-/* Handle a key press which closes a dead pane. */
+/* Handle a key press on a dead pane waiting for a key. */
 static int
 server_client_handle_dead_key(struct window_pane *wp, key_code key)
 {
-	int	remain_on_exit;
-
 	if (wp == NULL ||
 	    (~wp->flags & PANE_EXITED) ||
 	    KEYC_IS_MOUSE(key) ||
-	    KEYC_IS_PASTE(key))
-		return (0);
-	remain_on_exit = options_get_number(wp->options, "remain-on-exit");
-	if (remain_on_exit != 3 && remain_on_exit != 4)
+	    KEYC_IS_PASTE(key) ||
+	    options_get_number(wp->options, "remain-on-exit") != 3)
 		return (0);
 	options_set_number(wp->options, "remain-on-exit", 0);
 	server_destroy_pane(wp, 0);
@@ -1466,8 +1488,19 @@ server_client_key_callback(struct cmdq_item *item, void *data)
 		/*
 		 * Mouse drag is in progress, so fire the callback (now that
 		 * the mouse event is valid).
+		 *
+		 * Start a synchronized-output region here rather than
+		 * leaving it to whatever redraw eventually follows: a drag
+		 * callback may write directly via the pane's fast path
+		 * immediately, with any correction only arriving later via
+		 * redraw_client_damage(), which opens its own sync region.
+		 * Since tty_sync_end() is only called once, at the very end
+		 * of this client's pass in server_client_reset_state(),
+		 * starting it here merges both into one atomic terminal
+		 * update instead of two visible frames.
 		 */
 		if ((key & KEYC_MASK_KEY) == KEYC_DRAGGING) {
+			tty_sync_start(&c->tty);
 			c->tty.mouse_drag_update(c, m);
 			goto out;
 		}
@@ -1760,10 +1793,9 @@ server_client_handle_key0(struct client *c, struct key_event *event,
 	}

 	/*
-	 * Key presses in overlay mode, dead panes waiting for a key, modal cancel
-	 * keys, panes capturing all keys and the command prompt are special cases.
-	 * The queue might be blocked so they need to be processed immediately
-	 * rather than queued.
+	 * Key presses in overlay mode, for panes capturing all keys and in the
+	 * command prompt are a special case. The queue might be blocked so they
+	 * need to be processed immediately rather than queued.
 	 */
 	if (~c->flags & CLIENT_READONLY) {
 		if (c->message_string != NULL) {
@@ -1785,18 +1817,12 @@ server_client_handle_key0(struct client *c, struct key_event *event,
 		server_client_clear_overlay(c);

 		wp = s->curw->window->active;
-		if (server_client_handle_dead_key(wp, event->key))
-			return (0);
-		if (wp != NULL && wp == wp->window->modal &&
-		    (wp->flags & PANE_CLOSEONCANCEL) &&
-		    (event->key == '\033' || event->key == ('c'|KEYC_CTRL))) {
-			server_kill_pane(wp);
-			return (0);
-		}
 		if (wp != NULL &&
 		    (wp->flags & PANE_CAPTUREALLKEYS) &&
 		    TAILQ_EMPTY(&wp->modes) &&
 		    !KEYC_IS_MOUSE(event->key)) {
+			if (server_client_handle_dead_key(wp, event->key))
+				return (0);
 			if (~wp->flags & PANE_EXITED) {
 				window_pane_key(wp, c, s, s->curw, event->key,
 				    &event->m);
@@ -1911,7 +1937,12 @@ server_client_loop(void)

 	/*
 	 * Any windows will have been redrawn as part of clients, so clear
-	 * their flags now.
+	 * their flags now. A client whose redraw was deferred this pass
+	 * (waiting for outstanding tty output to drain) has already
+	 * escalated to CLIENT_REDRAWWINDOW or CLIENT_REDRAWSCROLLBARS in
+	 * server_client_check_redraw() to cover whatever it is about to
+	 * lose here, so PANE_REDRAW/PANE_REDRAWSCROLLBAR and window damage
+	 * can simply be cleared unconditionally.
 	 */
 	RB_FOREACH(w, windows, &windows) {
 		TAILQ_FOREACH(wp, &w->panes, entry) {
@@ -1922,6 +1953,8 @@ server_client_loop(void)
 			wp->flags &= ~(PANE_REDRAW|PANE_REDRAWSCROLLBAR|
 			    PANE_ACTIVITY);
 		}
+		redraw_free_damage(w);
+
 		check_window_name(w);
 	}

@@ -2470,6 +2503,8 @@ server_client_any_pane_redraw(struct client *c)

 	if (c->flags & CLIENT_REDRAWWINDOW)
 		return (1);
+	if (!TAILQ_EMPTY(&w->damage))
+		return (1);
 	TAILQ_FOREACH(wp, &w->panes, entry) {
 		if (wp->flags & (PANE_REDRAW|PANE_REDRAWSCROLLBAR))
 			return (1);
@@ -2515,7 +2550,12 @@ server_client_check_redraw(struct client *c)
 	/*
 	 * If there is outstanding data, defer the redraw until it has been
 	 * consumed. We can just add a timer to get out of the event loop and
-	 * end up back here.
+	 * end up back here. server_client_loop() clears PANE_REDRAW,
+	 * PANE_REDRAWSCROLLBAR and window damage unconditionally every pass,
+	 * so escalate to a coarser, persistent client flag that survives
+	 * that clear and forces a full catch-up redraw once this client is
+	 * unblocked, rather than trying to keep the fine-grained state
+	 * around for a retry.
 	 */
 	n = EVBUFFER_LENGTH(tty->out);
 	if (n != 0 || (tty->flags & TTY_BLOCK)) {
@@ -2529,6 +2569,8 @@ server_client_check_redraw(struct client *c)
 			log_debug("redraw timer started");
 			evtimer_add(&ev, &tv);
 		}
+		if (!TAILQ_EMPTY(&w->damage))
+			c->flags |= CLIENT_REDRAWWINDOW;
 		TAILQ_FOREACH(wp, &w->panes, entry) {
 			if (wp->flags & PANE_REDRAW) {
 				c->flags |= CLIENT_REDRAWWINDOW;
@@ -2562,6 +2604,19 @@ server_client_check_redraw(struct client *c)
 				redraw_pane_scrollbar(c, wp);
 			}
 		}
+
+		/*
+		 * Window damage is also what makes server_client_any_pane_
+		 * redraw() decide a redraw is needed at all, independently of
+		 * any CLIENT_ALLREDRAWFLAGS bit. Every current damage source
+		 * happens to set one of those flags too, so the block below
+		 * always consumes it - but consume it here too in case that
+		 * ever stops holding, since server_client_loop() clears
+		 * window damage unconditionally every pass regardless of
+		 * whether it was actually drawn.
+		 */
+		if (!TAILQ_EMPTY(&w->damage) && (~c->flags & CLIENT_ALLREDRAWFLAGS))
+			redraw_client_damage(c);
 	}

 	/*
@@ -2575,6 +2630,7 @@ server_client_check_redraw(struct client *c)
 		}
 		server_client_set_progress_bar(c);
 		redraw_screen(c);
+		redraw_client_damage(c);
 	}

 	/* Put the tty back how it was. */
--- a/server-fn.c
+++ b/server-fn.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: server-fn.c,v 1.153 2026/09/10 11:02:18 nicm Exp $ */
+/* $OpenBSD: server-fn.c,v 1.152 2026/09/03 19:12:36 nicm Exp $ */

 /*
 * Copyright (c) 2007 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -386,7 +386,6 @@ server_destroy_pane(struct window_pane *wp, int notify)
 	case 0:
 		break;
 	case 2:
-	case 4:
 		if (WIFEXITED(wp->status) && WEXITSTATUS(wp->status) == 0)
 			break;
 		/* FALLTHROUGH */
--- a/tmux.1
+++ b/tmux.1
@@ -1,4 +1,4 @@
-.\" $OpenBSD: tmux.1,v 1.1170 2026/09/11 10:17:16 nicm Exp $
+.\" $OpenBSD: tmux.1,v 1.1168 2026/09/09 07:03:39 nicm Exp $
 .\"
 .\" Copyright (c) 2007 Nicholas Marriott <nicholas.marriott@gmail.com>
 .\"
@@ -14,7 +14,7 @@
 .\" IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
 .\" OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 .\"
-.Dd $Mdocdate: September 11 2026 $
+.Dd $Mdocdate: September 9 2026 $
 .Dt TMUX 1
 .Os
 .Sh NAME
@@ -3655,7 +3655,7 @@ but a different format may be specified with
 .Fl F .
 .Tg newp
 .It Xo Ic new\-pane
-.Op Fl AbCDefhIkKLMOPvWZ
+.Op Fl AbCdefhIkKLMOPvWZ
 .Op Fl B Ar border\-lines
 .Op Fl c Ar start\-directory
 .Op Fl e Ar environment
@@ -3717,13 +3717,6 @@ all keys, including the prefix key, are passed directly to the modal pane.
 With
 .Fl C ,
 the modal pane is closed when the mouse is clicked outside it.
-With
-.Fl D ,
-the modal pane is closed when
-.Ql Escape
-or
-.Ql C-c
-is pressed.
 .Pp
 The
 .Fl L
@@ -5980,8 +5973,6 @@ single lines using ACS or UTF\-8 characters
 double lines using UTF\-8 characters
 .It heavy
 heavy lines using UTF\-8 characters
-.It rounded
-single lines with rounded corners using UTF\-8 characters
 .It simple
 simple ASCII characters
 .It number
@@ -6337,7 +6328,7 @@ uses when the colour with that index is requested.
 The index may be from zero to 255.
 .Pp
 .It Xo Ic remain\-on\-exit
-.Op Ic on | off | failed | key | failed\-key
+.Op Ic on | off | failed | key
 .Xc
 A pane with this flag set is not destroyed when the program running in it
 exits.
@@ -6347,10 +6338,6 @@ then only when the program exit status is not zero.
 If set to
 .Ic key ,
 the pane stays open and closes when a key is pressed.
-If set to
-.Ic failed\-key ,
-the pane stays open and closes when a key is pressed only if the program exit
-status is not zero.
 The pane may be reactivated with the
 .Ic respawn\-pane
 command.
--- a/tmux.h
+++ b/tmux.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: tmux.h,v 1.1440 2026/09/11 10:17:16 nicm Exp $ */
+/* $OpenBSD: tmux.h,v 1.1438 2026/09/09 08:30:05 nicm Exp $ */

 /*
 * Copyright (c) 2007 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -69,6 +69,7 @@ struct options_array_item;
 struct options_entry;
 struct prompt;
 struct window_pane_prompt;
+struct redraw_damage;
 struct redraw_scene;
 struct redraw_span;
 struct screen_write_citem;
@@ -1150,8 +1151,7 @@ enum pane_lines {
 	PANE_LINES_SIMPLE,
 	PANE_LINES_NUMBER,
 	PANE_LINES_SPACES,
-	PANE_LINES_NONE,
-	PANE_LINES_ROUNDED
+	PANE_LINES_NONE
 };

 /* Pane border indicator option. */
@@ -1340,7 +1340,6 @@ struct window_pane {
 #define PANE_CLOSEONCLICK 0x80000
 #define PANE_CAPTUREALLKEYS 0x100000
 #define PANE_FLOATOVERZOOM 0x200000
-#define PANE_CLOSEONCANCEL 0x400000

 	bitstr_t	*sync_dirty;
 	u_int		 sync_dirty_size;
@@ -1429,6 +1428,7 @@ struct window_pane {
 TAILQ_HEAD(window_panes, window_pane);
 TAILQ_HEAD(window_panes_zindex, window_pane);
 RB_HEAD(window_pane_tree, window_pane);
+TAILQ_HEAD(redraw_damages, redraw_damage);

 /* Window structure. */
 struct window {
@@ -1472,6 +1472,9 @@ struct window {

 	uint64_t		 redraw_scene_generation;

+	struct redraw_damages	 damage;
+	u_int			 damage_count;
+
 	struct menu_data	*menu;
 	u_int			 menu_last_px;
 	u_int			 menu_last_py;
@@ -1844,7 +1847,7 @@ struct tty {
 };

 /* Terminal command context. */
-typedef void (*tty_ctx_redraw_cb)(const struct tty_ctx *);
+typedef void (*tty_ctx_redraw_cb)(const struct tty_ctx *, u_int, u_int);
 typedef int (*tty_ctx_set_client_cb)(struct tty_ctx *, struct client *);
 struct tty_ctx {
 	struct screen		*s;
@@ -3659,8 +3662,12 @@ void	 redraw_screen(struct client *);
 void	 redraw_pane(struct client *, struct window_pane *);
 void	 redraw_pane_scrollbar(struct client *, struct window_pane *);
 void	 redraw_free_scene(struct redraw_scene *);
+int	 redraw_client_has_window(struct client *, struct window *);
 void	 redraw_invalidate_scene(struct window *);
 void	 redraw_invalidate_all_scenes(void);
+void	 redraw_damage_window(struct window *, u_int, u_int, u_int, u_int);
+void	 redraw_free_damage(struct window *);
+void	 redraw_client_damage(struct client *);
 int	 redraw_get_status_border_cell_type(struct redraw_span **, u_int);

 /* screen.c */
@@ -3834,6 +3841,8 @@ int		 window_pane_get_pane_status(struct window_pane *);
 struct style_range *window_pane_status_get_range(struct window_pane *, u_int,
 		     u_int);
 int		 window_pane_is_floating(struct window_pane *);
+void		 window_pane_redraw_floating(struct window *,
+		     struct window_pane *, int, int, int, int);

 /* window-border.c */
 void		 window_set_fill_cells(struct window *);
--- a/tty.c
+++ b/tty.c
@@ -1120,7 +1120,7 @@ tty_redraw_region(struct tty *tty, const struct tty_ctx *ctx)
 	 */
 	if (tty_large_region(tty, ctx) || ctx->flags & TTY_CTX_PANE_OBSCURED) {
 		log_debug("%s: %s large region redraw", __func__, c->name);
-		ctx->redraw_cb(ctx);
+		ctx->redraw_cb(ctx, ctx->orupper, ctx->orlower - ctx->orupper + 1);
 		return;
 	}

@@ -2032,7 +2032,7 @@ tty_cmd_alignmenttest(struct tty *tty, const struct tty_ctx *ctx)

 	if ((ctx->flags & TTY_CTX_WINDOW_BIGGER) ||
 	    c->overlay_check != NULL) {
-		ctx->redraw_cb(ctx);
+		ctx->redraw_cb(ctx, 0, ctx->sy);
 		return;
 	}

@@ -2114,7 +2114,7 @@ tty_cmd_cells(struct tty *tty, const struct tty_ctx *ctx)
 		    tty->cy == tty->rlower)
 			tty_draw_pane(tty, ctx, ctx->ocy);
 		else
-			ctx->redraw_cb(ctx);
+			ctx->redraw_cb(ctx, ctx->ocy, 1);
 		return;
 	}

--- a/window-border.c
+++ b/window-border.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: window-border.c,v 1.4 2026/09/11 10:17:16 nicm Exp $ */
+/* $OpenBSD: window-border.c,v 1.3 2026/07/23 09:38:27 nicm Exp $ */

 /*
 * Copyright (c) 2026 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -120,10 +120,6 @@ window_get_border_cell(struct window_pane *wp, enum pane_lines pane_lines,
 		gc->attr &= ~GRID_ATTR_CHARSET;
 		utf8_copy(&gc->data, tty_acs_heavy_borders(cell_type));
 		break;
-	case PANE_LINES_ROUNDED:
-		gc->attr &= ~GRID_ATTR_CHARSET;
-		utf8_copy(&gc->data, tty_acs_rounded_borders(cell_type));
-		break;
 	case PANE_LINES_SIMPLE:
 		gc->attr &= ~GRID_ATTR_CHARSET;
 		utf8_set(&gc->data, SIMPLE_BORDERS[cell_type]);
--- a/window.c
+++ b/window.c
@@ -415,6 +415,7 @@ window_create(u_int sx, u_int sy, u_int xpixel, u_int ypixel)
 	TAILQ_INIT(&w->panes);
 	TAILQ_INIT(&w->z_index);
 	TAILQ_INIT(&w->last_panes);
+	TAILQ_INIT(&w->damage);
 	w->active = NULL;

 	w->lastlayout = -1;
@@ -460,6 +461,7 @@ window_destroy(struct window *w)

 	menu_destroy(w);
 	window_destroy_panes(w);
+	redraw_free_damage(w);

 	if (event_initialized(&w->name_event))
 		evtimer_del(&w->name_event);
@@ -711,6 +713,7 @@ int
 window_set_active_pane(struct window *w, struct window_pane *wp, int notify)
 {
 	struct window_pane *lastwp;
+	int		    unzoomed;

 	log_debug("%s: pane %%%u", __func__, wp->id);

@@ -718,7 +721,8 @@ window_set_active_pane(struct window *w, struct window_pane *wp, int notify)
 		return (0);
 	if (w->modal != NULL && wp != w->modal)
 		return (0);
-	if ((w->flags & WINDOW_ZOOMED) && !window_pane_is_visible(wp))
+	unzoomed = (w->flags & WINDOW_ZOOMED) && !window_pane_is_visible(wp);
+	if (unzoomed)
 		window_unzoom(w, 1);
 	lastwp = w->active;

@@ -735,7 +739,19 @@ window_set_active_pane(struct window *w, struct window_pane *wp, int notify)
 	}

 	tty_update_window_offset(w);
-	server_redraw_window(w);
+
+	/*
+	 * Unzooming changes every pane's geometry and needs a full window
+	 * redraw. Otherwise, only the previous and new active pane's border
+	 * and status appearance changed, so avoid redrawing unaffected pane
+	 * content.
+	 */
+	if (unzoomed)
+		server_redraw_window(w);
+	else {
+		server_redraw_window_borders(w);
+		server_status_window(w);
+	}

 	if (notify)
 		window_fire_pane_changed(w, w->active, lastwp);
@@ -2906,3 +2922,109 @@ window_pane_is_floating(struct window_pane *wp)
 		return (0);
 	return (1);
 }
+
+/*
+ * Report damage for a floating pane's rectangle, grown by one cell on every
+ * side - a floating pane draws its border frame at xoff-1/yoff-1 through
+ * xoff+sx/yoff+sy (see the "floating" case in screen-redraw.c), one cell
+ * outside its own content area, so damage for just the content area leaves
+ * the frame's previous position undrawn as the pane moves. If a scrollbar
+ * is reserved, its side of the frame is pushed out further still by its
+ * width and padding (also matched in screen-redraw.c), so grow that side
+ * to match.
+ */
+static void
+window_pane_damage_floating(struct window *w, struct window_pane *wp,
+    int xoff, int yoff, int sx, int sy)
+{
+	int	x0, x1, y0, y1, sb_left = 0, sb_right = 0;
+
+	if (window_pane_scrollbar_reserve(wp)) {
+		if (w->sb_pos == PANE_SCROLLBARS_LEFT)
+			sb_left = wp->scrollbar_style.width +
+			    wp->scrollbar_style.pad;
+		else
+			sb_right = wp->scrollbar_style.width +
+			    wp->scrollbar_style.pad;
+	}
+
+	x0 = xoff - 1 - sb_left;
+	x1 = xoff + sx + sb_right;
+	y0 = yoff - 1;
+	y1 = yoff + sy;
+	if (x0 < 0)
+		x0 = 0;
+	if (y0 < 0)
+		y0 = 0;
+	if (x1 < x0 || y1 < y0)
+		return;
+	redraw_damage_window(w, (u_int)x0, (u_int)y0, (u_int)(x1 - x0) + 1,
+	    (u_int)(y1 - y0) + 1);
+}
+
+/*
+ * Whether a pane's scrollbar strip - not its whole body - intersects a
+ * window-coordinate rectangle. A reserved scrollbar occupies a strip of
+ * scrollbar_style.width+pad columns just outside the pane's own content
+ * area (see the scrollbar-reserve case in layout_fix_panes(), layout.c),
+ * on whichever side w->sb_pos points to.
+ */
+static int
+window_pane_scrollbar_intersects(struct window *w, struct window_pane *wp,
+    u_int x, u_int y, u_int sx, u_int sy)
+{
+	int	sb_x, sb_w, ix = (int)x, iy = (int)y, isx = (int)sx;
+	int	isy = (int)sy;
+
+	if (!window_pane_scrollbar_reserve(wp))
+		return (0);
+	sb_w = wp->scrollbar_style.width + wp->scrollbar_style.pad;
+	if (w->sb_pos == PANE_SCROLLBARS_LEFT)
+		sb_x = (int)wp->xoff - sb_w;
+	else
+		sb_x = (int)wp->xoff + (int)wp->sx;
+
+	return (sb_x < ix + isx && sb_x + sb_w > ix &&
+	    (int)wp->yoff < iy + isy && (int)wp->yoff + (int)wp->sy > iy);
+}
+
+/*
+ * Report damage for only a floating pane's old and new area, rather than
+ * the whole window - a floating pane move or resize only disturbs what it
+ * was covering and what it now covers. Scrollbars aren't covered by the
+ * damage system, so a pane whose *scrollbar strip* (not its whole body)
+ * intersects either area is still flagged directly for a scrollbar redraw.
+ * Checking the whole pane body here, rather than just its narrow scrollbar
+ * strip, meant merely dragging over a pane's ordinary content set
+ * PANE_REDRAWSCROLLBAR on every such pane on every motion event, triggering
+ * a needless scrollbar redraw (and the redraw pass it forces) each time
+ * even though the scrollbar itself never moved.
+ *
+ * Shared by every command that drags a floating pane around by the mouse:
+ * resize-pane's own border drag (cmd-resize-pane.c), move-pane -M's
+ * alternate Alt-drag (cmd-join-pane.c), and split-window/new-pane's
+ * interactive resize of a newly-created floating pane (cmd-split-window.c).
+ */
+void
+window_pane_redraw_floating(struct window *w, struct window_pane *wp,
+    int old_xoff, int old_yoff, int old_sx, int old_sy)
+{
+	struct window_pane	*loop;
+
+	window_pane_damage_floating(w, wp, old_xoff, old_yoff, old_sx,
+	    old_sy);
+	window_pane_damage_floating(w, wp, wp->xoff, wp->yoff, wp->sx,
+	    wp->sy);
+
+	TAILQ_FOREACH(loop, &w->panes, entry) {
+		if (window_pane_scrollbar_intersects(w, loop,
+		    (u_int)old_xoff, (u_int)old_yoff, (u_int)old_sx,
+		    (u_int)old_sy) ||
+		    window_pane_scrollbar_intersects(w, loop, wp->xoff,
+		    wp->yoff, wp->sx, wp->sy))
+			loop->flags |= PANE_REDRAWSCROLLBAR;
+	}
+
+	/* Session status formats may depend on the pane's new geometry. */
+	server_status_window(w);
+}
Author	SHA1	Message	Date
Michael Grant	07d40d5fa9	cmd-attach-session: redraw pane styles when changing active pane Call window_redraw_active_switch() before selecting a pane so differing window-style and window-active-style colours are updated immediately.\n\nAdd a regression test for selecting a pane through attach-session.	2026-09-14 04:36:57 +01:00
Nicholas Marriott	80e87aaf16	Merge branch 'master' into redraw-damage-rectangles	2026-09-09 14:05:48 +01:00
Michael Grant	f41b983e04	screen-write, tty, popup, window: fix remaining untested damage gaps Two more fixes based on Michael K. Darling's branch (github.com/darlingm/tmux, pr5516-regression-fixes), taken as-is - neither is caught by any test in regress/ yet, found by code review rather than a failing test: - screen_write_redraw_cb() (screen-write.c) reported damage for only a single row, using ttyctx->ocy as if every fallback redraw were a single-cell write. But it's also the callback for cases that can legitimately span many rows - a large scroll-region fallback (tty_redraw_region(), when tty_large_region() or the pane is obscured), a full reset, and entering/leaving the alternate screen. For those, only the top row of the affected area ever got marked as damaged, leaving the rest stale until an unrelated redraw happened to cover it. Changed the shared tty_ctx_redraw_cb typedef to carry (py, ny) - the actual row range - and updated every call site to pass the range it actually knows about, instead of hardcoding a single row. - window_pane_redraw_floating() (window.c) never refreshed the status line after moving/resizing a floating pane, so a status format depending on that pane's geometry (e.g. #{pane_width}) could go stale until an unrelated status refresh happened. Added a server_status_window(w) call. Also confirmed the window_pane_scrollbar_intersects() parameter naming cleanup (loop -> wp) discussed earlier was already done in an earlier "Cleanup." commit - nothing left to do there. All 9 tests in regress/ plus the two pre-existing floating-pane tests plus a further 19-test sweep of redraw/tty/input/sync-adjacent regress tests pass. Co-Authored-By: Michael K. Darling <darlingm@gmail.com> Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>	2026-08-25 10:49:46 +01:00
Michael Grant	48e33179d4	server-client, popup, screen-redraw: fix damage-system regressions Fixes the four bugs caught by the regression tests added in `aed1209c` (popup-drag-status-line.sh, popup-drag-wide-character.sh, popup-drag-pane-prompt.sh, switch-client-redraw.sh), based on fixes from Michael K. Darling (github.com/darlingm/tmux, pr5516-regression- fixes), reviewed and adapted: - server-client.c: server_client_set_session()'s check for whether the client's window actually changed compared old->curw to s->curw, but when old == s these read the same, already-updated field, so a same-session window switch was never detected. Compare against the client's own cached redraw scene instead (redraw_client_has_window(), new in screen-redraw.c/tmux.h). Taken from darlingm as-is. - popup.c: popup_damage() only translated a popup's client-coordinate rectangle into window coordinates, so a popup dragged across the status line never triggered a status-line redraw once it moved away - status_redraw()'s own "skip if content unchanged" optimization suppressed it, since only the popup moved, not the status content. Now detects overlap with the status line and forces a redraw via the existing (previously unused) CLIENT_REDRAWSTATUSALWAYS flag, and properly clips the reported rectangle to the pane area for status-at-top/bottom/off. Taken from darlingm as-is. - screen-redraw.c: redraw_draw_damage_rect() clipped a span to a damage rectangle's raw geometric edges, which have no idea what's in the grid, so a clip edge could land mid-character and tear a wide character in half. Added redraw_damage_grow_span_clip(): widen the clip by one cell on each edge that isn't already at the span's own boundary. Reimplemented simpler than darlingm's version (which walked grid cells per span type via a switch and direct grid lookups) - since no grid cell is ever wider than two columns, an unconditional one-cell margin is always enough to pull a split character back in, with no need to inspect grid content at all. - screen-redraw.c: redraw_draw_damage_rect() also never re-overlaid a pane's active in-pane prompt after drawing its underlying content, so damage crossing a prompt row erased it until an unrelated redraw restored it. Factored the existing full-redraw prompt-building code into a shared redraw_make_pane_prompt() helper and added redraw_damage_draw_pane_prompt(), which recomposes the prompt over the drawn range. Taken from darlingm as-is. All 9 regression tests in regress/ now pass. redraw_damage_grow_span_clip was verified independently by disabling it and confirming popup-drag-wide-character.sh reproduces its original failure. Co-Authored-By: Michael K. Darling <darlingm@gmail.com> Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>	2026-08-25 10:25:29 +01:00
Michael Grant	aed1209c02	regress: add Michael K. Darling's damage/redraw regression tests From github.com/darlingm/tmux, branch pr5516-regression-fixes. Adds 9 regression tests covering gaps found in the redraw-damage-rectangles branch: screen-write full/region redraw fallback, same-session window switches, wide-character clipping at damage edges, pane prompts and status lines surviving damage, floating-pane status format refresh, and multi-client damage delivery. redraw-multiclient.sh is adapted here to use ASCII pane borders (pane-border-lines simple) instead of darlingm's original UTF-8 borders: the original reliably "failed" under this test's nested tmux-in-tmux harness (relaying through an outer tmux client) due to that harness mis-rendering a cell that held a multi-byte UTF-8 border character being overwritten by later plain content - confirmed to be a nested-relay artifact, not a real bug, by replaying the identical drag sequence against a real terminal (xterm), where it never reproduces. ASCII borders avoid the artifact; the test still reliably catches the real "damage consumed by only one client" bug it targets (verified by reintroducing that bug and confirming the test fails). The other 8 tests are added verbatim from darlingm's branch. Four of them (popup-drag-status-line.sh, popup-drag-wide-character.sh, popup-drag-pane-prompt.sh, switch-client-redraw.sh) currently FAIL on this branch, since the source fixes they test for have not been merged yet - only the tests are being added here. Co-Authored-By: Michael K. Darling <darlingm@gmail.com> Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>	2026-08-25 10:14:49 +01:00
Michael Grant	6739bd03f5	Merge remote-tracking branch 'origin/master' into redraw-damage-rectangles # Conflicts: # server-client.c # window.c	2026-08-25 08:08:17 +01:00
Michael Grant	f66eeef8a5	Added a fallback in server_client_check_redraw() as recommended by codex to catch an unserviced edge-case.	2026-08-24 13:36:34 +01:00
Michael Grant	2d220d9a7f	Cleanup.	2026-08-24 13:25:12 +01:00
Michael Grant	da4895d559	popup: damage-based redraw during drag/resize instead of full client redraw popup_handle_drag()'s MOVE and SIZE branches each called server_redraw_client(c) unconditionally, redrawing the client's entire window on every drag step. Report damage for just the popup's old and new rectangle instead, via a new popup_damage() (translating from raw client/tty coordinates into window coordinates), and set CLIENT_REDRAWOVERLAY so the popup itself still redraws.	2026-08-22 16:54:25 +01:00
Michael Grant	b254f557e4	md-join-pane, cmd-split-window, cmd-resize-pane: use shared floating-pane redraw instead of full client redraw The three interactive mouse-drag paths that move or resize a floating pane (move-pane -M's Alt-drag, split-window/new-pane's interactive resize, and resize-pane's own border drag) each unconditionally called server_redraw_window(w), redrawing every pane in the window for a change that only ever disturbs the floating pane's own old and new rectangle. Switch all three to window_pane_redraw_floating().	2026-08-22 16:53:08 +01:00
Michael Grant	b26eeb5229	window: redraw only borders/status on active-pane change window_set_active_pane() unconditionally called server_redraw_window(w) on every active-pane change, redrawing every pane's content even though only the previous and new active pane's border/status appearance actually changed. Unzooming (which does change every pane's geometry) still gets the full redraw; otherwise this now only redraws borders and status.	2026-08-22 16:42:56 +01:00
Michael Grant	48cdd85886	server-client: consume window damage during the normal redraw pass redraw_client_damage() (added previously, unused until now) is called from server_client_check_redraw()'s normal redraw pass, and server_client_any_pane_redraw() now also checks for pending window damage so a client with only damage (no PANE_REDRAW/PANE_REDRAWSCROLLBAR flags) still gets its redraw pass run. server_client_check_redraw() now returns whether the redraw was deferred (waiting for outstanding tty output to drain) rather than performed. A deferred redraw no longer escalates to a full CLIENT_REDRAWWINDOW to avoid losing what was pending - server_client_loop() now only clears PANE_REDRAW, PANE_REDRAWSCROLLBAR and window damage once every client viewing a window actually drew this pass (tracked via a new per-window redraw_deferred flag), otherwise they're left in place and retried in their normal, narrowly-scoped form. server_client_set_session() now redraws only if the client's session or current window actually changed, not on every call (e.g. switch-client -t= from clicking a pane name in the status line resolves here even when nothing besides the active pane changed). A drag callback's mouse_drag_update() now opens a sync region itself (tty_sync_start()) before its first write, so a fast-path write it makes directly and a later correction arriving via redraw_client_damage() end up in the same atomic terminal update instead of two visible frames.	2026-08-22 16:36:25 +01:00
Michael Grant	f255f089fc	window: add floating-pane damage/redraw helpers window_pane_redraw_floating() reports damage for only a floating pane's old and new rectangle (via redraw_damage_window(), grown by one cell to cover its border frame - see the "floating" case in screen-redraw.c), instead of the caller falling back to a full window redraw. Any other pane whose scrollbar strip - not its whole body - intersects either rectangle still gets PANE_REDRAWSCROLLBAR directly, since scrollbars aren't covered by the damage system.	2026-08-22 16:32:21 +01:00
Michael Grant	d6074895bb	screen-redraw, screen-write: add damage-rectangle tracking and composition Introduce a per-window list of damaged rectangles (struct redraw_damage) and redraw_damage_window() to record them, redraw_client_damage() to consume them by composing exactly the damaged cells (via a new redraw_draw_damage_rect(), which also force-refreshes any pane-status span it touches, since window_make_pane_status()'s content-diff check has no way to know the physical cells were disturbed by something else). redraw_draw_span() now takes an explicit [clip_x, clip_x + clip_n) range instead of always drawing a span's full width, so a damage rectangle can redraw just the portion of a span it actually covers. screen_write_redraw_cb() - the fallback when a write can't be applied directly to the terminal - now reports damage for just the affected row via this mechanism, instead of unconditionally flagging the whole pane for a full redraw.	2026-08-22 15:45:29 +01:00
Michael Grant	faba411289	layout: only mark scrollbar for redraw when the pane actually changed wp->flags \|= PANE_REDRAWSCROLLBAR was set unconditionally whenever a pane reserved a scrollbar, even if layout_fix_panes() left its geometry completely unchanged - forcing a needless scrollbar redraw on every layout pass. Move it inside the existing "did this pane's geometry actually change" check.	2026-08-22 13:51:03 +01:00