Merge remote-tracking branch 'refs/remotes/tmux-openbsd/master'

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

CHANGES

@@ -33,9 +33,7 @@ CHANGES FROM 3.7c TO 3.8
     line;
 
   - pane-border-status has top-floating and bottom-floating, and there are new
-    default bindings under C-b g for common move and resize operations;
+    default bindings under C-b g for common move and resize operations.
-
-  - floating panes are unzoomed before creation to avoid a crash.
 
 * Layout strings now use a JSON subset format which includes floating panes.
   The old format is still accepted; control mode clients receive old layouts
@@ -132,6 +130,8 @@ 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.

cmd-split-window.c

@@ -1,4 +1,4 @@
-/* $OpenBSD: cmd-split-window.c,v 1.150 2026/08/20 09:19:24 nicm Exp $ */
+/* $OpenBSD: cmd-split-window.c,v 1.151 2026/09/10 11:02:18 nicm Exp $ */
 
 /*
  * Copyright (c) 2009 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -40,8 +40,8 @@ const struct cmd_entry cmd_new_pane_entry = {
 	.name = "new-pane",
 	.alias = "newp",
 
-	.args = { "AbB:Cc:de:EfF:hIkl:KLMm:Op:PR:s:S:t:T:vWx:X:y:Y:Z", 0, -1, NULL },
+	.args = { "AbB:Cc:Dde:EfF:hIkl:KLMm:Op:PR:s:S:t:T:vWx:X:y:Y:Z", 0, -1, NULL },
-	.usage = "[-AbCdefhIkKLMOPvWZ] [-B border-lines] "
+	.usage = "[-AbCDefhIkKLMOPvWZ] [-B border-lines] "
 		 "[-c start-directory] [-e environment] "
 		 "[-F format] [-l size] [-m message] [-p percentage] "
 		 "[-s style] [-S active-border-style] "
@@ -219,6 +219,8 @@ 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) {

configure.ac

@@ -1,6 +1,6 @@
 # configure.ac
 
-AC_INIT([tmux], next-3.8)
+AC_INIT([tmux], next-3.9)
 AC_PREREQ([2.60])
 
 AC_CONFIG_AUX_DIR(etc)

layout-custom.c

@@ -1,4 +1,4 @@
-/* $OpenBSD: layout-custom.c,v 1.40 2026/09/09 07:03:39 nicm Exp $ */
+/* $OpenBSD: layout-custom.c,v 1.41 2026/09/09 09:01:19 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 legacy
+ * Layouts can be represented as strings in a JSON format (v2). The version 1
- * format (v1) will be removed in the future and should no longer be used.
+ * format 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
@@ -57,6 +57,9 @@
  *    "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;
@@ -362,7 +365,7 @@ layout_append_v2(struct layout_cell *lc, struct layout_string *ls)
 	return (0);
 }
 
-/* Append information for a single cell in the legacy (v1) format. */
+/* Append information for a single cell in the version 1 format. */
 static int
 layout_append_v1(struct layout_cell *lc, struct layout_string *ls)
 {
@@ -778,7 +781,7 @@ layout_assign(struct window *w, struct layout_parse_ctx *pctx)
 		layout_assign_fallback(w, w->layout_root);
 }
 
-/* Construct a cell from the legacy (v1) format. */
+/* Construct a cell from the version 1 format. */
 static struct layout_cell *
 layout_construct_cell(struct layout_cell *lcparent, const char **layout)
 {
@@ -827,12 +830,15 @@ layout_construct_cell(struct layout_cell *lcparent, const char **layout)
 	return (lc);
 }
 
-/* Construct a layout from the legacy (v1) format. */
+/* Construct a layout from the version 1 format. */
 static struct layout_cell *
-layout_construct_v1(struct layout_cell *lcparent, const char **layout)
+layout_construct_v1(struct layout_cell *lcparent, const char **layout, u_int depth)
 {
 	struct layout_cell	*lc, *lcchild;
 
+	if (depth > LAYOUT_V1_MAX_DEPTH)
+		return (NULL);
+
 	lc = layout_construct_cell(lcparent, layout);
 	if (lc == NULL)
 		return (NULL);
@@ -855,7 +861,7 @@ layout_construct_v1(struct layout_cell *lcparent, const char **layout)
 
 	do {
 		(*layout)++;
-		lcchild = layout_construct_v1(lc, layout);
+		lcchild = layout_construct_v1(lc, layout, depth + 1);
 		if (lcchild == NULL)
 			goto fail;
 		TAILQ_INSERT_TAIL(&lc->cells, lcchild, entry);
@@ -1068,7 +1074,8 @@ layout_construct(const char *input, struct layout_parse_ctx *pctx)
 			*pctx->cause = xstrdup("invalid layout checksum");
 			return (-1);
 		}
-		if ((pctx->root = layout_construct_v1(NULL, &input)) == NULL) {
+		pctx->root = layout_construct_v1(NULL, &input, 0);
+		if (pctx->root == NULL) {
 			*pctx->cause = xstrdup("invalid layout");
 			return (-1);
 		}

layout.c

@@ -1,4 +1,4 @@
-/* $OpenBSD: layout.c,v 1.99 2026/09/09 07:03:39 nicm Exp $ */
+/* $OpenBSD: layout.c,v 1.100 2026/09/11 08:16:14 nicm Exp $ */
 
 /*
  * Copyright (c) 2009 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -768,6 +768,49 @@ layout_free(struct window *w, int only_nodes)
 	layout_free_cell(w->layout_root, only_nodes);
 }
 
+/* Move and resize floating panes so they stay inside the window. */
+static void
+layout_clamp_floating_panes(struct window *w, u_int sx, u_int sy)
+{
+	struct window_pane	*wp;
+	struct layout_cell	*lc;
+	u_int			 pad, avail, csx, csy;
+
+	TAILQ_FOREACH(wp, &w->z_index, zentry) {
+		lc = wp->layout_cell;
+		if (lc == NULL || (~lc->flags & LAYOUT_CELL_FLOATING))
+			continue;
+		if (window_pane_get_pane_lines(wp) == PANE_LINES_NONE)
+			pad = 0;
+		else
+			pad = 1;
+
+		csx = lc->g.sx;
+		avail = (sx > 2 * pad) ? sx - 2 * pad : 0;
+		if (csx > avail)
+			csx = (avail > PANE_MINIMUM) ? avail : PANE_MINIMUM;
+		csy = lc->g.sy;
+		avail = (sy > 2 * pad) ? sy - 2 * pad : 0;
+		if (csy > avail)
+			csy = (avail > PANE_MINIMUM) ? avail : PANE_MINIMUM;
+		if (csx != lc->g.sx || csy != lc->g.sy)
+			layout_set_size(lc, csx, csy, lc->g.xoff, lc->g.yoff);
+
+		if (lc->g.xoff + lc->g.sx + pad > sx) {
+			if (lc->g.sx + 2 * pad >= sx)
+				lc->g.xoff = pad;
+			else
+				lc->g.xoff = sx - lc->g.sx - pad;
+		}
+		if (lc->g.yoff + lc->g.sy + pad > sy) {
+			if (lc->g.sy + 2 * pad >= sy)
+				lc->g.yoff = pad;
+			else
+				lc->g.yoff = sy - lc->g.sy - pad;
+		}
+	}
+}
+
 /* Resize the entire layout after window resize. */
 void
 layout_resize(struct window *w, u_int sx, u_int sy)
@@ -788,8 +831,11 @@ layout_resize(struct window *w, u_int sx, u_int sy)
 	 * out proportionately - this should leave the layout fitting the new
 	 * window size.
 	 */
-	if (lc->type == LAYOUT_WINDOWPANE && (lc->flags & LAYOUT_CELL_FLOATING))
+	if (lc->type == LAYOUT_WINDOWPANE && (lc->flags & LAYOUT_CELL_FLOATING)) {
+		layout_clamp_floating_panes(w, sx, sy);
+		layout_fix_panes(w, NULL);
 		return;
+	}
 	xchange = sx - lc->g.sx;
 	xlimit = layout_resize_check(w, lc, LAYOUT_LEFTRIGHT);
 	if (xchange < 0 && xchange < -xlimit)
@@ -819,6 +865,7 @@ layout_resize(struct window *w, u_int sx, u_int sy)
 
 	/* Fix cell offsets. */
 	layout_fix_offsets(w);
+	layout_clamp_floating_panes(w, sx, sy);
 	layout_fix_panes(w, NULL);
 }
 

options-table.c

@@ -1,4 +1,4 @@
-/* $OpenBSD: options-table.c,v 1.244 2026/09/01 12:49:49 nicm Exp $ */
+/* $OpenBSD: options-table.c,v 1.246 2026/09/11 10:17:16 nicm Exp $ */
 
 /*
  * Copyright (c) 2011 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -76,7 +76,8 @@ static const char *options_table_pane_border_indicators_list[] = {
 	"off", "colour", "arrows", "both", NULL
 };
 static const char *options_table_pane_border_lines_list[] = {
-	"single", "double", "heavy", "simple", "number", "spaces", "none", NULL
+	"single", "double", "heavy", "simple", "number", "spaces", "none",
+	"rounded", NULL
 };
 static const char *options_table_popup_border_lines_list[] = {
 	"single", "double", "heavy", "simple", "rounded", "padded", "none", NULL
@@ -91,7 +92,7 @@ static const char *options_table_window_size_list[] = {
 	"largest", "smallest", "manual", "latest", NULL
 };
 static const char *options_table_remain_on_exit_list[] = {
-	"off", "on", "failed", "key", NULL
+	"off", "on", "failed", "key", "failed-key", NULL
 };
 static const char *options_table_destroy_unattached_list[] = {
 	"off", "on", "keep-last", "keep-group", NULL
@@ -1698,7 +1699,8 @@ const struct options_table_entry options_table[] = {
 	  .choices = options_table_remain_on_exit_list,
 	  .default_num = 0,
 	  .text = "Whether panes should remain ('on'), remain until a key is "
-		  "pressed ('key') or be automatically killed ('off' or "
+		  "pressed after any exit ('key') or after a failure "
+		  "('failed-key'), or be automatically killed ('off' or "
 		  "'failed') when the program inside exits."
 	},
 

regress/control-client-sanity.sh

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

regress/floating-pane-geometry.sh

@@ -268,5 +268,149 @@ $TMUX kill-pane -t "$floating" || exit 1
 $TMUX kill-pane -t "$right" || exit 1
 $TMUX kill-pane -t "$lower" || exit 1
 
+# --- Floating panes clamped when the window shrinks (issue #5581, PR #5582) ---
+#
+# layout_resize clamps floating panes back inside the window when it shrinks:
+# move them and, only if they cannot fit, shrink them (never below
+# PANE_MINIMUM). A floating cell is the pane's content, so with the default
+# single-line border the clamp counts 1 cell of border per side, exactly as
+# layout_floating_args_parse does on creation; with no border it counts 0.
+# Each case below gets its own window, since resize-window fixes a window at
+# a manual size for the rest of its life.
+
+# Case 1: a lone floating pane -- break-pane -W on a window's only pane --
+# takes the early-return path in layout_resize, added during PR #5582's
+# review round, since there is no tiled tree to walk.
+win=$($TMUX new-window -dPF '#{window_id}') ||
+	fail "new-window for lone float failed"
+
+# -x 20 -y 6 -> pane 18x4; -X 60 -Y 18 -> pane_left 61, pane_top 19: with the
+# border, the footprint is columns 60-79, rows 18-23, flush with the 80x24
+# window's right and bottom edges, so the float fits before it is shrunk.
+$TMUX break-pane -W -s "$win" -x 20 -y 6 -X 60 -Y 18 ||
+	fail "break-pane -W for lone float failed"
+must_equal "$($TMUX display-message -p -t "$win" '#{pane_width}')"  18
+must_equal "$($TMUX display-message -p -t "$win" '#{pane_height}')" 4
+must_equal "$($TMUX display-message -p -t "$win" '#{pane_left}')"   61
+must_equal "$($TMUX display-message -p -t "$win" '#{pane_top}')"    19
+
+# Shrink to 40x16. The float still fits at its own size (18 <= 40-2, 4 <=
+# 16-2) so only its position moves, flush to the new right/bottom edges:
+# xoff = 40 - 18 - 1 = 21; yoff = 16 - 4 - 1 = 11.
+$TMUX resize-window -t "$win" -x 40 -y 16 ||
+	fail "resize-window (lone float) failed"
+must_equal "$($TMUX display-message -p -t "$win" '#{pane_width}')"  18
+must_equal "$($TMUX display-message -p -t "$win" '#{pane_height}')" 4
+must_equal "$($TMUX display-message -p -t "$win" '#{pane_left}')"   21
+must_equal "$($TMUX display-message -p -t "$win" '#{pane_top}')"    11
+
+# Case 5: grow the window back. The clamp must not chase the window back
+# outward -- it only ever pulls a float in, never restores where it was.
+$TMUX resize-window -t "$win" -x 80 -y 24 ||
+	fail "resize-window grow (lone float) failed"
+must_equal "$($TMUX display-message -p -t "$win" '#{pane_width}')"  18
+must_equal "$($TMUX display-message -p -t "$win" '#{pane_height}')" 4
+must_equal "$($TMUX display-message -p -t "$win" '#{pane_left}')"   21
+must_equal "$($TMUX display-message -p -t "$win" '#{pane_top}')"    11
+$TMUX kill-window -t "$win" || exit 1
+
+# Case 2: the same float, but with a tiled sibling surviving alongside it, so
+# the window's root cell stays tiled and layout_resize takes the normal path
+# (the clamp call after layout_fix_offsets) instead of the early return
+# above. Same geometry as case 1, so the same numbers should come out.
+win=$($TMUX new-window -dPF '#{window_id}') ||
+	fail "new-window for tiled sibling failed"
+$TMUX split-window -t "$win" 'sleep 100' ||
+	fail "split-window for tiled sibling failed"
+$TMUX break-pane -W -s "$win" -x 20 -y 6 -X 60 -Y 18 ||
+	fail "break-pane -W for tiled sibling failed"
+must_equal "$($TMUX display-message -p -t "$win" '#{pane_width}')"  18
+must_equal "$($TMUX display-message -p -t "$win" '#{pane_height}')" 4
+must_equal "$($TMUX display-message -p -t "$win" '#{pane_left}')"   61
+must_equal "$($TMUX display-message -p -t "$win" '#{pane_top}')"    19
+
+$TMUX resize-window -t "$win" -x 40 -y 16 ||
+	fail "resize-window (tiled sibling) failed"
+must_equal "$($TMUX display-message -p -t "$win" '#{pane_width}')"  18
+must_equal "$($TMUX display-message -p -t "$win" '#{pane_height}')" 4
+must_equal "$($TMUX display-message -p -t "$win" '#{pane_left}')"   21
+must_equal "$($TMUX display-message -p -t "$win" '#{pane_top}')"    11
+$TMUX kill-window -t "$win" || exit 1
+
+# Case 3: new-pane float, the original repro from issue #5581 and the PR
+# body -- also the normal path, via the tiled base pane new-window creates.
+win=$($TMUX new-window -dPF '#{window_id}') ||
+	fail "new-window for new-pane repro failed"
+$TMUX resize-window -t "$win" -x 120 -y 40 ||
+	fail "resize-window to 120x40 failed"
+
+# -x 30 -y 10 -> pane 28x8; -X 85 -Y 25 -> pane_left 86, pane_top 26.
+floating=$($TMUX new-pane -t "$win" -dPF '#{pane_id}' \
+	-x 30 -y 10 -X 85 -Y 25 'sleep 100') ||
+	fail "new-pane for new-pane repro failed"
+must_equal "$($TMUX display-message -p -t "$floating" '#{pane_width}')"  28
+must_equal "$($TMUX display-message -p -t "$floating" '#{pane_height}')" 8
+must_equal "$($TMUX display-message -p -t "$floating" '#{pane_left}')"   86
+must_equal "$($TMUX display-message -p -t "$floating" '#{pane_top}')"    26
+
+# Shrink to 60x20: xoff = 60 - 28 - 1 = 31; yoff = 20 - 8 - 1 = 11.
+$TMUX resize-window -t "$win" -x 60 -y 20 ||
+	fail "resize-window (new-pane repro) failed"
+must_equal "$($TMUX display-message -p -t "$floating" '#{pane_width}')"  28
+must_equal "$($TMUX display-message -p -t "$floating" '#{pane_height}')" 8
+must_equal "$($TMUX display-message -p -t "$floating" '#{pane_left}')"   31
+must_equal "$($TMUX display-message -p -t "$floating" '#{pane_top}')"    11
+$TMUX kill-window -t "$win" || exit 1
+
+# Case 4: a float that already fits inside the shrunk window is left alone --
+# assert position and size are both unchanged, not just one of them.
+win=$($TMUX new-window -dPF '#{window_id}') ||
+	fail "new-window for untouched float failed"
+
+# -x 20 -y 6 -> pane 18x4; -X 8 -Y 3 -> pane_left 9, pane_top 4 (as at the top
+# of this file). Footprint columns 8-27, rows 3-8: well inside 60x20 too.
+floating=$($TMUX new-pane -t "$win" -dPF '#{pane_id}' \
+	-x 20 -y 6 -X 8 -Y 3 'sleep 100') ||
+	fail "new-pane for untouched float failed"
+must_equal "$($TMUX display-message -p -t "$floating" '#{pane_width}')"  18
+must_equal "$($TMUX display-message -p -t "$floating" '#{pane_height}')" 4
+must_equal "$($TMUX display-message -p -t "$floating" '#{pane_left}')"   9
+must_equal "$($TMUX display-message -p -t "$floating" '#{pane_top}')"    4
+
+$TMUX resize-window -t "$win" -x 60 -y 20 ||
+	fail "resize-window (untouched float) failed"
+must_equal "$($TMUX display-message -p -t "$floating" '#{pane_width}')"  18
+must_equal "$($TMUX display-message -p -t "$floating" '#{pane_height}')" 4
+must_equal "$($TMUX display-message -p -t "$floating" '#{pane_left}')"   9
+must_equal "$($TMUX display-message -p -t "$floating" '#{pane_top}')"    4
+$TMUX kill-window -t "$win" || exit 1
+
+# Case 6: pad = 0, via the pane-border-lines window option set to none. The
+# border arithmetic differs here (no -2/+1 adjustment either on creation or
+# in the clamp).
+win=$($TMUX new-window -dPF '#{window_id}') ||
+	fail "new-window for pad=0 float failed"
+$TMUX set-option -w -t "$win" pane-border-lines none ||
+	fail "set pane-border-lines none failed"
+
+# No border: -x 20 -y 6 -> pane 20x6 directly; -X 60 -Y 18 -> pane_left 60,
+# pane_top 18 directly. Footprint (== content, no border) is columns 60-79,
+# rows 18-23: flush right/bottom of the 80x24 window, same as case 1.
+$TMUX break-pane -W -s "$win" -x 20 -y 6 -X 60 -Y 18 ||
+	fail "break-pane -W for pad=0 float failed"
+must_equal "$($TMUX display-message -p -t "$win" '#{pane_width}')"  20
+must_equal "$($TMUX display-message -p -t "$win" '#{pane_height}')" 6
+must_equal "$($TMUX display-message -p -t "$win" '#{pane_left}')"   60
+must_equal "$($TMUX display-message -p -t "$win" '#{pane_top}')"    18
+
+# Shrink to 40x16 with pad=0: xoff = 40 - 20 - 0 = 20; yoff = 16 - 6 - 0 = 10.
+$TMUX resize-window -t "$win" -x 40 -y 16 ||
+	fail "resize-window (pad=0 float) failed"
+must_equal "$($TMUX display-message -p -t "$win" '#{pane_width}')"  20
+must_equal "$($TMUX display-message -p -t "$win" '#{pane_height}')" 6
+must_equal "$($TMUX display-message -p -t "$win" '#{pane_left}')"   20
+must_equal "$($TMUX display-message -p -t "$win" '#{pane_top}')"    10
+$TMUX kill-window -t "$win" || exit 1
+
 $TMUX kill-server 2>/dev/null
 exit 0

regress/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 -OKPF '#{pane_id}' -t "$p0" \
+modal=$($TMUX new-pane -ODKPF '#{pane_id}' -t "$p0" \
     -x 20 -y 5 -X 20 -Y 10 'cat') ||
-	fail "new-pane -OK failed"
+	fail "new-pane -ODK failed"
 sleep 1
 $TMUX2 send-keys -t "$OUTER" C-b x z Enter
 sleep 1
@@ -356,9 +356,50 @@ 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'

regress/options-values.sh

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

regress/pane-ops.sh

@@ -104,6 +104,25 @@ assert_alive()
 	fi
 }
 
+# Compare layout geometry and pane ordering, ignoring the active pane and
+# last-pane history in the JSON layout. Selection is checked separately.
+pane_layout()
+{
+	$TMUX display-message -p -t "$1" '#{window_layout}' |
+		sed 's/,"a":true//g; s/,"l":[0-9][0-9]*//g'
+}
+
+check_layout()
+{
+	out=$(pane_layout "$1")
+	if [ "$out" != "$2" ]; then
+		echo "Layout for '$1' wrong."
+		echo "Expected: '$2'"
+		echo "But got:  '$out'"
+		exit 1
+	fi
+}
+
 # ---------------------------------------------------------------------------
 # split-window geometry.
 
@@ -309,12 +328,12 @@ 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=$($TMUX display-message -p -t P:0 '#{window_layout}')
+layout=$(pane_layout P:0)
 check_ok select-pane -t "$p0"
 check_ok resize-pane -Z -t "$p0"
 check_ok select-pane -t "$p2"
 check_fmt "$p2" '#{window_zoomed_flag}:#{pane_active}' '0:1'
-check_fmt P:0 '#{window_layout}' "$layout"
+check_layout P:0 "$layout"
 
 check_ok select-pane -t "$p0"
 check_ok resize-pane -Z -t "$p0"
@@ -322,7 +341,7 @@ 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 "$p2"
-check_fmt P:0 '#{window_layout}' "$layout"
+check_layout P:0 "$layout"
 
 # Directional selection temporarily restores the full layout to find its
 # neighbour, then follows the same unzoom or -Z transfer rules.
@@ -340,7 +359,7 @@ 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 "$p2"
-check_fmt P:0 '#{window_layout}' "$layout"
+check_layout P:0 "$layout"
 
 # The last-pane path has separate zoom handling, both with and without -Z.
 check_ok select-pane -t "$p0"
@@ -357,7 +376,7 @@ check_ok select-pane -l -Z -t P:0
 check_fmt "$p0" '#{window_zoomed_flag}:#{pane_zoomed_flag}:#{pane_active}' \
 	'1:1:1'
 check_ok resize-pane -Z -t "$p0"
-check_fmt P:0 '#{window_layout}' "$layout"
+check_layout P:0 "$layout"
 
 # Killing either a hidden ordinary pane or the zoom target unzooms.
 check_ok new-window -d -t P:12 -n zoom-kill 'cat'

regress/screen-redraw-floating.sh

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

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

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

server-client.c

@@ -1,4 +1,4 @@
-/* $OpenBSD: server-client.c,v 1.511 2026/09/08 10:20:08 nicm Exp $ */
+/* $OpenBSD: server-client.c,v 1.512 2026/09/10 11:02:18 nicm Exp $ */
 
 /*
  * Copyright (c) 2009 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -1391,15 +1391,19 @@ server_client_repeat_time(struct client *c, struct key_binding *bd)
 	return (repeat);
 }
 
-/* Handle a key press on a dead pane waiting for a key. */
+/* Handle a key press which closes a dead pane. */
 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) ||
+	    KEYC_IS_PASTE(key))
-	    options_get_number(wp->options, "remain-on-exit") != 3)
+		return (0);
+	remain_on_exit = options_get_number(wp->options, "remain-on-exit");
+	if (remain_on_exit != 3 && remain_on_exit != 4)
 		return (0);
 	options_set_number(wp->options, "remain-on-exit", 0);
 	server_destroy_pane(wp, 0);
@@ -1756,9 +1760,10 @@ server_client_handle_key0(struct client *c, struct key_event *event,
 	}
 
 	/*
-	 * Key presses in overlay mode, for panes capturing all keys and in the
+	 * Key presses in overlay mode, dead panes waiting for a key, modal cancel
-	 * command prompt are a special case. The queue might be blocked so they
+	 * keys, panes capturing all keys and the command prompt are special cases.
-	 * need to be processed immediately rather than queued.
+	 * 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) {
@@ -1780,12 +1785,18 @@ 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);

server-fn.c

@@ -1,4 +1,4 @@
-/* $OpenBSD: server-fn.c,v 1.152 2026/09/03 19:12:36 nicm Exp $ */
+/* $OpenBSD: server-fn.c,v 1.153 2026/09/10 11:02:18 nicm Exp $ */
 
 /*
  * Copyright (c) 2007 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -386,6 +386,7 @@ 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 */

tmux.1

@@ -1,4 +1,4 @@
-.\" $OpenBSD: tmux.1,v 1.1168 2026/09/09 07:03:39 nicm Exp $
+.\" $OpenBSD: tmux.1,v 1.1170 2026/09/11 10:17:16 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 9 2026 $
+.Dd $Mdocdate: September 11 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
@@ -3717,6 +3717,13 @@ 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
@@ -5973,6 +5980,8 @@ 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
@@ -6328,7 +6337,7 @@ 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
+.Op Ic on | off | failed | key | failed\-key
 .Xc
 A pane with this flag set is not destroyed when the program running in it
 exits.
@@ -6338,6 +6347,10 @@ 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.

tmux.h

@@ -1,4 +1,4 @@
-/* $OpenBSD: tmux.h,v 1.1438 2026/09/09 08:30:05 nicm Exp $ */
+/* $OpenBSD: tmux.h,v 1.1440 2026/09/11 10:17:16 nicm Exp $ */
 
 /*
  * Copyright (c) 2007 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -1150,7 +1150,8 @@ enum pane_lines {
 	PANE_LINES_SIMPLE,
 	PANE_LINES_NUMBER,
 	PANE_LINES_SPACES,
-	PANE_LINES_NONE
+	PANE_LINES_NONE,
+	PANE_LINES_ROUNDED
 };
 
 /* Pane border indicator option. */
@@ -1339,6 +1340,7 @@ 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;

window-border.c

@@ -1,4 +1,4 @@
-/* $OpenBSD: window-border.c,v 1.3 2026/07/23 09:38:27 nicm Exp $ */
+/* $OpenBSD: window-border.c,v 1.4 2026/09/11 10:17:16 nicm Exp $ */
 
 /*
  * Copyright (c) 2026 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -120,6 +120,10 @@ 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]);