Merge branch 'redraw-damage-rectangles' into 4902-image-support

Brings in the WezTerm/ghostty/Windows Terminal DECSLRM (margins) coverage from margins-terminal-detection (PR #5630), via redraw-damage-rectangles. Two conflicts, both simple bit-flag/list collisions from independent work on both sides adding something at the same slot: - tmux.h: this branch's own TERM_KITTY/TERM_IMAGE_QUADRANTS/ TERM_IMAGE_SEXTANTS (0x100/0x200/0x400) collided with upstream's new TERM_NOREPLACE, also assigned 0x100. Kept this branch's existing values (already used throughout image.c/tty-features.c) and moved TERM_NOREPLACE to the next free bit, 0x800 - confirmed no other code references the literal 0x100 value for TERM_NOREPLACE, only the symbol. - tty-features.c: this branch's own WezTerm entry (added "sixel") and the incoming margins-terminal-detection change (added "margins") both touched the same line - combined both. Verified: build clean with --enable-images (image_support confirmed 1); this branch's own image-kitty-region-scroll.sh/image-sixel-region-scroll.sh plus this session's other prompt/cross-client/margins tests all pass (3x each); full regress suite run pending/clean per standard practice for this branch. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
2026-09-24 05:43:58 +00:00 · 2026-09-23 08:59:12 +01:00
parent bfda809f98 238067acbf
commit f44699a18c
17 changed files with 634 additions and 42 deletions
--- a/cmd-queue.c
+++ b/cmd-queue.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: cmd-queue.c,v 1.123 2026/08/24 20:34:26 nicm Exp $ */
+/* $OpenBSD: cmd-queue.c,v 1.124 2026/09/22 06:46:50 nicm Exp $ */

 /*
 * Copyright (c) 2013 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -580,6 +580,9 @@ cmdq_fire_command(struct cmdq_item *item)
 	int			 flags, quiet = 0;
 	char			*tmp;

+	if (item->client != NULL && (item->client->flags & CLIENT_DEAD))
+		return (CMD_RETURN_ERROR);
+
 	if (cfg_finished)
 		cmdq_add_message(item);
 	if (log_get_level() > 1) {
--- a/cmd-wait-for.c
+++ b/cmd-wait-for.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: cmd-wait-for.c,v 1.23 2026/07/10 13:38:45 nicm Exp $ */
+/* $OpenBSD: cmd-wait-for.c,v 1.24 2026/09/22 06:46:50 nicm Exp $ */

 /*
 * Copyright (c) 2013 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -480,6 +480,40 @@ cmd_wait_for_unlock(struct cmdq_item *item, const char *name,
 	return (CMD_RETURN_NORMAL);
 }

+void
+cmd_wait_for_client_lost(struct client *c)
+{
+	struct wait_channel	*wc, *wc1;
+	struct wait_item	*wi, *wi1;
+	struct wait_event_item	*wei, *wei1;
+
+	TAILQ_FOREACH_SAFE(wei, &wait_event_items, entry, wei1) {
+		if (cmdq_get_client(wei->item) == c) {
+			TAILQ_REMOVE(&wait_event_items, wei, entry);
+			cmdq_continue(wei->item);
+			cmd_wait_for_event_free(wei);
+		}
+	}
+
+	RB_FOREACH_SAFE(wc, wait_channels, &wait_channels, wc1) {
+		TAILQ_FOREACH_SAFE(wi, &wc->waiters, entry, wi1) {
+			if (cmdq_get_client(wi->item) == c) {
+				cmdq_continue(wi->item);
+				TAILQ_REMOVE(&wc->waiters, wi, entry);
+				free(wi);
+			}
+		}
+		TAILQ_FOREACH_SAFE(wi, &wc->lockers, entry, wi1) {
+			if (cmdq_get_client(wi->item) == c) {
+				cmdq_continue(wi->item);
+				TAILQ_REMOVE(&wc->lockers, wi, entry);
+				free(wi);
+			}
+		}
+		cmd_wait_for_remove_empty(wc);
+	}
+}
+
 void
 cmd_wait_for_flush(void)
 {
--- a/layout-custom.c
+++ b/layout-custom.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: layout-custom.c,v 1.42 2026/09/20 08:37:47 nicm Exp $ */
+/* $OpenBSD: layout-custom.c,v 1.43 2026/09/22 06:48:01 nicm Exp $ */

 /*
 * Copyright (c) 2010 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -307,6 +307,37 @@ bad:
 	return (xstrdup("0000,"));
 }

+/* Get a floating pane cell's z-index in the layout being dumped. */
+static u_int
+layout_cell_zindex(struct layout_cell *lc)
+{
+	struct window_pane	*wp = lc->wp, *wq;
+	struct window		*w = wp->window;
+	struct layout_cell	*other;
+	int			 saved = (lc == wp->saved_layout_cell);
+	u_int			 i = 0;
+
+	if (saved &&
+	    w->active != NULL &&
+	    (w->active->flags & PANE_ZOOMED) &&
+	    (w->active->saved_layout_cell->flags & LAYOUT_CELL_FLOATING)) {
+		if (wp == w->active)
+			return (0);
+		i++;
+	}
+	TAILQ_FOREACH(wq, &w->z_index, zentry) {
+		if (wq == wp)
+			break;
+		if (saved)
+			other = wq->saved_layout_cell;
+		else
+			other = wq->layout_cell;
+		if (other != NULL && (other->flags & LAYOUT_CELL_FLOATING))
+			i++;
+	}
+	return (i);
+}
+
 /* Append information for a single cell in a JSON (v2) format. */
 static int
 layout_append_v2(struct layout_cell *lc, struct layout_string *ls)
@@ -315,7 +346,7 @@ layout_append_v2(struct layout_cell *lc, struct layout_string *ls)
 	struct window_pane	*wp;
 	enum layout_type	 type;
 	char			 c;
-	u_int			 i, n;
+	u_int			 i, n, z;

 	if (lc == NULL)
 		return (-1);
@@ -356,9 +387,10 @@ layout_append_v2(struct layout_cell *lc, struct layout_string *ls)
 		if (window_pane_index(wp, &i) != 0)
 			return (-1);
 		layout_string_write(ls, ",\"i\":%u", i);
-		if ((lc->flags & LAYOUT_CELL_FLOATING) &&
-		    window_pane_zindex(wp, &i) == 0)
-			layout_string_write(ls, ",\"z\":%u", i);
+		if (lc->flags & LAYOUT_CELL_FLOATING) {
+			z = layout_cell_zindex(lc);
+			layout_string_write(ls, ",\"z\":%u", z);
+		}
 		layout_string_write(ls, ",\"I\":\"%%%u\"", wp->id);
 	}

--- a/regress/input-keys.sh
+++ b/regress/input-keys.sh
@@ -22,7 +22,19 @@ assert_key () {
 	      clear-history -t$W \; \
 	      send-keys -t$W "$key" 'EOL' || exit 1

-	actual_code=$($TMUX capturep -pt$W | \
+	# cat echoes the keys back asynchronously, so wait for the EOL marker
+	# to reach the pane instead of capturing straight away.
+	i=0
+	while [ $i -lt 50 ]; do
+		screen=$($TMUX capturep -pt$W)
+		case "$screen" in
+		*EOL*) break ;;
+		esac
+		i=$((i + 1))
+		sleep 0.1
+	done
+
+	actual_code=$(printf '%s\n' "$screen" | \
 			      head -1 | \
 			      sed -e 's/EOL.*$//')

--- a/regress/input-malformed.sh
+++ b/regress/input-malformed.sh
@@ -2,13 +2,13 @@

 . ./input-common.inc

-# Large strings may take longer than start_cmd's delay to reach the parser.
+# Wait for the terminator and following text to reach the parser.
 check_discard()
 {
 	name=$1
 	printf 'OK\n' >"$EXP"
 	i=0
-	while [ "$i" -lt 100 ]; do
+	while [ "$i" -lt 300 ]; do
 		capture_grid "$name" >"$TMP"
 		cmp -s "$TMP" "$EXP" && return 0
 		sleep 0.05
@@ -17,6 +17,23 @@ check_discard()
 	fail "$name (timed out waiting for discard)"
 }

+# The missing-terminator timer may expire before the string limit is reached
+# on a slow build. Clear any payload printed after the timeout, then check
+# that the string did not change the title and normal output has resumed.
+test_discard()
+{
+	name=$1
+	prefix=$2
+	start_cmd "$name" 8 3 "$INPUT_HOLD"
+	$TMUX select-pane -T discard-test || exit 1
+	$TMUX respawn-pane -k \
+	    "perl -e 'print qq{$prefix}, q{x} x 1100000, qq{\e\\\\\e[H\e[2JOK}'; $INPUT_HOLD" || exit 1
+	check_discard "$name"
+	$TMUX display-message -p -t "$name:" '#{pane_title}' >"$TMP" || exit 1
+	printf 'discard-test\n' >"$EXP"
+	cmp "$TMP" "$EXP" || fail "$name title"
+}
+
 start_cmd csi-param-discard 8 3 \
    "perl -e 'print qq{\e[}, q{1} x 80, qq{\030OK}'; sleep 2"
 check_capture csi-param-discard 'OK'
@@ -25,13 +42,8 @@ start_cmd csi-interm-discard 8 3 \
    "perl -e 'print qq{\e[    \030OK}'; sleep 2"
 check_capture csi-interm-discard 'OK'

-start_cmd osc-discard 8 3 \
-    "perl -e 'print qq{\e]2;}, q{x} x 1100000, qq{\e\\\\OK}'; exec cat"
-check_discard osc-discard
-
-start_cmd apc-discard 8 3 \
-    "perl -e 'print qq{\e_}, q{x} x 1100000, qq{\e\\\\OK}'; exec cat"
-check_discard apc-discard
+test_discard osc-discard '\e]2;'
+test_discard apc-discard '\e_'

 start_pane unknown-csi 8 3 '\033[?9999zOK'
 check_capture unknown-csi 'OK'
--- a/regress/layout-custom.sh
+++ b/regress/layout-custom.sh
@@ -377,10 +377,7 @@ must_equal 'Layout after select-pane back' "$(layout L:two)" "$SPLIT"

 # With nothing zoomed the two layout formats agree.
 #
-# The zoomed case is deliberately not covered here. While a pane is zoomed
-# #{window_layout} dumps the saved (unzoomed) layout and
-# #{window_visible_layout} the zoomed one, but that depends on how zooming
-# stashes the layout root rather than on anything in layout-custom.c.
+# Zoomed layouts are checked below with floating panes.
 must_equal 'Visible layout' "$(visible_layout L:two)" "$SPLIT"

 # ---------------------------------------------------------------------------
@@ -704,6 +701,42 @@ must_contain 'Floating layout back z-index' "$floating" '"z":1'
 check_ok select-layout -t L:float "$floating"
 must_equal 'Floating layout after round trip' "$(raw_layout L:float)" "$floating"

+# A dump taken while zoomed must retain the unzoomed floating z-indexes.
+# Check hidden floats, floats above zoom, and a mixture of the two.
+for flags in '' A mixed; do
+	check_ok new-window -d -t L: -n zoom
+	zt=$($TMUX display-message -p -t L:zoom '#{pane_id}')
+	check_ok split-window -d -h -t "$zt"
+	case "$flags" in
+	A|mixed) first=-Ad ;;
+	*) first=-d ;;
+	esac
+	case "$flags" in
+	A) second=-Ad ;;
+	*) second=-d ;;
+	esac
+	check_ok new-pane "$first" -t "$zt" -x 20 -y 6 ''
+	check_ok new-pane "$second" -t "$zt" -x 30 -y 8 ''
+	for pane in 0 2 3; do
+		check_ok select-pane -t "L:zoom.$pane"
+		before=$(raw_layout L:zoom)
+		legacy=$(v1_layout L:zoom)
+		check_ok resize-pane -Z -t "L:zoom.$pane"
+		during=$(raw_layout L:zoom)
+		must_equal 'Layout while zoomed' "$during" "$before"
+		must_equal 'Legacy layout while zoomed' \
+		    "$(v1_layout L:zoom)" "$legacy"
+		must_equal 'Zoom after dumping layout' \
+		    "$($TMUX display-message -p -t L:zoom '#{window_zoomed_flag}')" 1
+		must_differ 'Visible layout while zoomed' \
+		    "$(visible_layout L:zoom)" "$(layout L:zoom)"
+		check_ok select-layout -t L:zoom "$during"
+		must_equal 'Round trip from zoomed layout' \
+		    "$(raw_layout L:zoom)" "$before"
+	done
+	check_ok kill-window -t L:zoom
+done
+
 # ---------------------------------------------------------------------------
 # Floating panes and the legacy (v1) format.
 #
--- a/regress/sync-output-wrapped.sh
+++ b/regress/sync-output-wrapped.sh
@@ -0,0 +1,116 @@
+#!/bin/sh
+
+# When only some lines are redrawn after a synchronized update, a line
+# following a wrapped line must be drawn at its own position, not where the
+# cursor happens to be.
+
+PATH=/bin:/usr/bin
+TERM=screen
+LC_ALL=C.UTF-8
+export PATH TERM LC_ALL
+
+[ -z "$TEST_TMUX" ] && TEST_TMUX=$(readlink -f ../tmux)
+
+DIR=$(mktemp -d) || exit 1
+TMUX_TMPDIR=$DIR
+export TMUX_TMPDIR
+
+INNER="$TEST_TMUX -Li$$ -f/dev/null"
+OUTER="$TEST_TMUX -Lo$$ -f/dev/null"
+CONTROL=$DIR/control
+EMITTER=$DIR/emitter.pl
+
+fail()
+{
+	echo "$*" >&2
+	exit 1
+}
+
+cleanup()
+{
+	$OUTER kill-server 2>/dev/null
+	$INNER kill-server 2>/dev/null
+	rm -rf "$DIR"
+}
+trap cleanup 0 1 15
+
+wait_for_file()
+{
+	i=0
+	while [ "$i" -lt 50 ] && [ ! -e "$1" ]; do
+		sleep 0.1
+		i=$((i + 1))
+	done
+	[ -e "$1" ] || fail "$2"
+}
+
+wait_for_client()
+{
+	i=0
+	while [ "$i" -lt 50 ]; do
+		$INNER list-clients -F '#{client_termfeatures}' 2>/dev/null |
+		    grep -q 'sync' && return 0
+		sleep 0.1
+		i=$((i + 1))
+	done
+	fail "sync-capable client did not attach"
+}
+
+cat >"$EMITTER" <<'PERL'
+use strict;
+use warnings;
+
+my $control = $ENV{CONTROL};
+(my $dir = $control) =~ s{/[^/]+$}{};
+
+# Fill the screen with 80 column lines and no newlines so every line wraps.
+my $out = "\e[H\e[2J";
+for my $row (1 .. 24) {
+	$out .= substr(sprintf("ROW%02d_", $row) . ('x' x 80), 0, 80);
+}
+syswrite STDOUT, $out . "\e[1;1H";
+
+open my $painted, '>', "$dir/painted" or die "$dir/painted: $!\n";
+close $painted;
+while (!-e $control) {
+	select undef, undef, undef, 0.01;
+}
+
+# Change rows 2 and 6 in one synchronized update.
+my $frame = "\e[?2026h" .
+    "\e[2;1H" . substr("NEW02_" . ('#' x 80), 0, 80) .
+    "\e[6;1H" . substr("NEW06_" . ('%' x 80), 0, 80) .
+    "\e[24;1H" .
+    "\e[?2026l";
+my $written = syswrite STDOUT, $frame;
+die "short synchronized frame write\n"
+    unless defined $written && $written == length $frame;
+open my $done, '>', "$dir/done" or die "$dir/done: $!\n";
+close $done;
+select undef, undef, undef, 3;
+PERL
+
+$INNER new-session -d -s inner -x 80 -y 24 \
+    "CONTROL='$CONTROL' perl '$EMITTER'" || exit 1
+$INNER set-option -g status off || exit 1
+$INNER set-option -g window-size manual || exit 1
+$INNER set-option -as terminal-features '*:sync' || exit 1
+
+$OUTER new-session -d -s outer -x 80 -y 24 \
+    "$TEST_TMUX -Li$$ -f/dev/null attach-session -t inner" ||
+    exit 1
+$OUTER set-option -g status off || exit 1
+$OUTER set-option -g window-size manual || exit 1
+wait_for_client
+
+wait_for_file "$DIR/painted" "application did not paint"
+sleep 1
+: >"$CONTROL"
+wait_for_file "$DIR/done" "application did not finish"
+sleep 1
+
+$OUTER capture-pane -p -t outer:0.0 >"$DIR/screen" || exit 1
+sed -n 2p "$DIR/screen" | grep -q '^NEW02_#' || fail "row 2 not redrawn"
+sed -n 3p "$DIR/screen" | grep -q '^ROW03_x' || fail "row 3 overwritten"
+sed -n 6p "$DIR/screen" | grep -q '^NEW06_%' || fail "row 6 not redrawn"
+exit 0
--- a/regress/tty-margins-wt-session.sh
+++ b/regress/tty-margins-wt-session.sh
@@ -0,0 +1,124 @@
+#!/bin/sh
+
+# Windows Terminal cannot be identified by the XTVERSION mechanism
+# tty_default_features() (tty-features.c) otherwise uses for every other
+# terminal in its table - its maintainers have explicitly declined to
+# implement it (github.com/microsoft/terminal issue 18382, closed
+# not_planned). tty_term_create() (tty-term.c) instead detects it via the
+# WT_SESSION environment variable Windows Terminal sets for every child
+# process, granting it the "margins" (DECSLRM) terminal feature.
+#
+# Without DECSLRM, a pane that doesn't span the terminal's full width -
+# because pane-scrollbars is on (the scrollbar occupies a column) or the
+# pane is one of a side-by-side split - can't use the fast native-scroll
+# path (tty_cmd_linefeed()/scrollup()/scrolldown()/reverseindex(), tty.c:
+# "(!tty_full_width(tty, ctx) && !tty_use_margin(tty))") and falls back to
+# tty_redraw_region()'s full manual repaint on every single scroll - a
+# real, confirmed source of flicker (and, separately, of image content not
+# surviving a scroll).
+#
+# This checks the actual server-side decision via the -vv log: a pane with
+# pane-scrollbars on, scrolled several times, must never fall back to
+# tty_redraw_region() when the attaching client's environment carries
+# WT_SESSION - and must (as a sanity check that this scenario would
+# otherwise hit the fallback at all) when it does not.
+
+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
+cd "$DIR" || exit 1
+INNER="$TEST_TMUX -vv -Lwtsession-inner-$$ -f/dev/null"
+OUTER="$TEST_TMUX -Lwtsession-outer-$$ -f/dev/null"
+
+fail()
+{
+	echo "$*" >&2
+	exit 1
+}
+
+cleanup()
+{
+	$OUTER kill-server 2>/dev/null
+	$INNER kill-server 2>/dev/null
+	cd /
+	rm -rf "$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"
+}
+
+run_scroll_phase()
+{
+	label=$1
+	attachcmd=$2
+
+	rm -f tmux-server*.log
+
+	$INNER new-session -d -s inner -x 40 -y 6 'exec sh' || exit 1
+	$INNER set -g status off || exit 1
+	$INNER set -g window-size manual || exit 1
+	$INNER set -g pane-scrollbars on || exit 1
+
+	$OUTER new-session -d -x 40 -y 6 || exit 1
+	OUTERPANE=$($OUTER list-panes -F '#{pane_id}') || exit 1
+	$OUTER set -g status off || exit 1
+	$OUTER set -g window-size manual || exit 1
+	$OUTER set -g default-terminal screen-256color || exit 1
+	$OUTER send-keys -t "$OUTERPANE" -l "$attachcmd" || exit 1
+	$OUTER send-keys -t "$OUTERPANE" Enter || exit 1
+	sleep 1
+
+	wait_for_client
+
+	i=0
+	while [ "$i" -lt 8 ]; do
+		$INNER send-keys -t inner Enter || exit 1
+		sleep 0.2
+		i=$((i + 1))
+	done
+	sleep 0.3
+
+	LOG=$(ls tmux-server*.log 2>/dev/null | head -1)
+	[ -n "$LOG" ] || fail "$label: sanity: no server -vv log was produced"
+
+	n=$(grep -c "tty_redraw_region.*large region redraw" "$LOG")
+
+	$OUTER kill-server 2>/dev/null
+	$INNER kill-server 2>/dev/null
+
+	echo "$n"
+}
+
+# Phase 1: WT_SESSION present in the attaching client's environment - must
+# never fall back to a full region redraw.
+n_with=$(run_scroll_phase "with WT_SESSION" \
+    "WT_SESSION=deadbeef-0000-0000-0000-000000000000 $INNER attach -t inner")
+[ "$n_with" -eq 0 ] ||
+	fail "with WT_SESSION set, scrolling a scrollbar-enabled pane still fell back to a full region redraw ($n_with times) - margins was not granted"
+
+# Phase 2: sanity check - without WT_SESSION, the same scenario must
+# actually hit the fallback, proving phase 1 wasn't accidentally trivial.
+# Explicitly strip WT_SESSION/WSLENV rather than relying on them being
+# unset in the ambient environment - this test may itself be run from
+# inside a real Windows Terminal/WSL session.
+n_without=$(run_scroll_phase "without WT_SESSION" \
+    "env -u WT_SESSION -u WSLENV $INNER attach -t inner")
+[ "$n_without" -gt 0 ] ||
+	fail "sanity: without WT_SESSION, scrolling a scrollbar-enabled pane never fell back to a full region redraw - this scenario no longer exercises the bug this test checks for"
+
+exit 0
--- a/regress/wait-for-client-lost.sh
+++ b/regress/wait-for-client-lost.sh
@@ -0,0 +1,164 @@
+#!/bin/sh
+
+# A disconnected waiter must release both its wait and its command queue.
+PATH=/bin:/usr/bin
+TERM=screen
+export TERM
+
+[ -z "$TEST_TMUX" ] && TEST_TMUX=$(readlink -f ../tmux)
+OUT=$(mktemp -d)
+TMUX="$TEST_TMUX -S$OUT/socket -f/dev/null"
+pids=
+
+cleanup()
+{
+	for pid in $pids; do
+		kill "$pid" 2>/dev/null || true
+	done
+	$TMUX kill-server 2>/dev/null || true
+	rm -rf "$OUT"
+}
+trap cleanup EXIT
+
+fail()
+{
+	echo "$*" >&2
+	exit 1
+}
+
+wait_list()
+{
+	expected=$1
+	shift
+	i=0
+	while [ $i -lt 100 ]; do
+		value=$($TMUX wait-for -l "$@") || fail "list waiters failed"
+		[ "$value" = "$expected" ] && return
+		i=$((i + 1))
+		sleep 0.05
+	done
+	fail "expected waiters '$expected', got '$value'"
+}
+
+wait_free()
+{
+	client_pid=$1
+	i=0
+	while [ $i -lt 100 ]; do
+		awk -v pid="$client_pid" '
+		    $4 == "IDENTIFY_CLIENTPID" && $5 == pid { address = $3 }
+		    address != "" && $2 == "free" && $3 == "client" &&
+		    $4 == address && $5 == "(0" { freed = 1 }
+		    END { exit !freed }
+		' "$OUT"/tmux-server-*.log && return
+		i=$((i + 1))
+		sleep 0.05
+	done
+	fail "client $client_pid was not freed"
+}
+
+cd "$OUT" || exit 1
+$TMUX -vv new-session -d -s test || fail "new-session failed"
+$TMUX set -g @continued 0 || fail "set option failed"
+
+for signal in TERM KILL; do
+	for kind in channel lock event; do
+		name="$kind-$signal"
+		case $kind in
+		channel) args="$name"; list_args="$name" ;;
+		lock)
+			$TMUX wait-for -L "$name" || fail "lock failed"
+			args="-L $name"; list_args="$name"
+			;;
+		event) args="-E @$name"; list_args="-E @$name" ;;
+		esac
+
+		$TMUX wait-for $args \; set -g @continued 1 &
+		dead=$!
+		pids="$dead"
+		wait_list "client-$dead" $list_args
+
+		$TMUX wait-for $args &
+		live=$!
+		pids="$dead $live"
+		wait_list "$(printf 'client-%s\nclient-%s' "$dead" "$live")" \
+		    $list_args
+
+		kill -"$signal" "$dead" || fail "kill failed"
+		wait "$dead" 2>/dev/null || true
+		pids="$live"
+		wait_list "client-$live" $list_args
+		wait_free "$dead"
+		[ "$($TMUX show -gqv @continued)" = 0 ] ||
+			fail "disconnected client's next command ran"
+
+		case $kind in
+		channel) $TMUX wait-for -S "$name" || fail "signal failed" ;;
+		lock) $TMUX wait-for -U "$name" || fail "unlock failed" ;;
+		event)
+			$TMUX wait-for -E -w "client-$live" "@$name" ||
+				fail "wake event waiter failed"
+			;;
+		esac
+		wait_list "" $list_args
+		wait_free "$live"
+		wait "$live" || fail "surviving waiter failed"
+		pids=
+		if [ "$kind" = lock ]; then
+			$TMUX wait-for -U "$name" || fail "final unlock failed"
+		fi
+	done
+done
+
+# Removing the last waiter must remove its otherwise unused channel, and must
+# not create a pending signal. Unrelated pending signals must be preserved.
+$TMUX wait-for -S saved || fail "save signal failed"
+$TMUX wait-for last &
+dead=$!
+pids="$dead"
+wait_list "client-$dead" last
+kill -KILL "$dead" || fail "kill last waiter failed"
+wait "$dead" 2>/dev/null || true
+pids=
+wait_list "" last
+wait_free "$dead"
+grep -F 'remove empty wait channel last' "$OUT"/tmux-server-*.log \
+    >/dev/null || fail "empty channel was not removed"
+
+$TMUX wait-for saved \; wait-for last &
+live=$!
+pids="$live"
+wait_list "client-$live" last
+$TMUX wait-for -S last || fail "signal last failed"
+wait_free "$live"
+wait "$live" || fail "pending signal was not preserved"
+pids=
+
+# Source-file leaves a cleanup callback behind the blocked command.
+printf 'wait-for sourced\nset -g @continued 1\n' >"$OUT/source.conf"
+$TMUX source-file "$OUT/source.conf" &
+dead=$!
+pids="$dead"
+wait_list "client-$dead" sourced
+kill -KILL "$dead" || fail "kill source-file waiter failed"
+wait "$dead" 2>/dev/null || true
+pids=
+wait_list "" sourced
+wait_free "$dead"
+[ "$($TMUX show -gqv @continued)" = 0 ] ||
+	fail "disconnected source-file client's next command ran"
+
+# Firing an event after cancellation must not call the removed event sink.
+$TMUX wait-for -E window-renamed &
+dead=$!
+pids="$dead"
+wait_list "client-$dead" -E window-renamed
+kill -KILL "$dead" || fail "kill event waiter failed"
+wait "$dead" 2>/dev/null || true
+pids=
+wait_list "" -E window-renamed
+wait_free "$dead"
+$TMUX rename-window -t test:0 renamed || fail "rename-window failed"
+$TMUX display-message -p '#{pid}' >/dev/null || fail "server exited"
+
+exit 0
--- a/screen-redraw.c
+++ b/screen-redraw.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: screen-redraw.c,v 1.160 2026/09/21 10:22:31 nicm Exp $ */
+/* $OpenBSD: screen-redraw.c,v 1.161 2026/09/22 16:56:07 nicm Exp $ */

 /*
 * Copyright (c) 2026 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -1990,7 +1990,7 @@ redraw_draw_pane_prompt(struct redraw_draw_ctx *dctx, struct window_pane *wp)
 		width = sx - px;

 	redraw_make_pane_prompt(wp, &screen);
-	tty_draw_line(tty, &screen, 0, offset, width, px, cy, NULL);
+	tty_draw_line(tty, &screen, offset, 0, width, px, cy, NULL);
 	screen_free(&screen);
 }

--- a/server-client.c
+++ b/server-client.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: server-client.c,v 1.513 2026/09/21 10:22:31 nicm Exp $ */
+/* $OpenBSD: server-client.c,v 1.514 2026/09/22 06:46:50 nicm Exp $ */

 /*
 * Copyright (c) 2009 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -411,6 +411,9 @@ server_client_lost(struct client *c)
 	TAILQ_REMOVE(&clients, c, entry);
 	log_debug("lost client %p", c);

+	cmd_wait_for_client_lost(c);
+	cmdq_next(c);
+
 	if (c->flags & CLIENT_ATTACHED) {
 		server_client_attached_lost(c);
 		events_fire_client("client-detached", c);
--- a/tmux.1
+++ b/tmux.1
@@ -1,4 +1,4 @@
-.\" $OpenBSD: tmux.1,v 1.1171 2026/09/21 10:22:31 nicm Exp $
+.\" $OpenBSD: tmux.1,v 1.1172 2026/09/22 06:58:05 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 21 2026 $
+.Dd $Mdocdate: September 22 2026 $
 .Dt TMUX 1
 .Os
 .Sh NAME
@@ -5085,6 +5085,9 @@ The available features are:
 .Bl -tag -width Ds
 .It 256
 Supports 256 colours with the SGR escape sequences.
+.It appesc
+Supports application escape key mode, where the Escape key sends a sequence
+that cannot be mistaken for the start of another key.
 .It clipboard
 Allows setting the system clipboard.
 .It ccolour
@@ -8841,6 +8844,8 @@ These are set automatically if the
 capability is present.
 .It Em \&Dseks , \&Eneks
 Disable and enable extended keys.
+.It Em \&Dsesc , \&Enesc
+Disable and enable application escape key mode.
 .It Em \&Dsfcs , \&Enfcs
 Disable and enable focus reporting.
 These are set automatically if the
--- a/tmux.h
+++ b/tmux.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: tmux.h,v 1.1444 2026/09/21 12:14:32 nicm Exp $ */
+/* $OpenBSD: tmux.h,v 1.1447 2026/09/22 14:10:26 nicm Exp $ */

 /*
 * Copyright (c) 2007 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -470,6 +470,7 @@ enum tty_code_code {
 	TTYC_DL1,
 	TTYC_DSBP,
 	TTYC_DSEKS,
+	TTYC_DSESC,
 	TTYC_DSFCS,
 	TTYC_DSMG,
 	TTYC_E3,
@@ -480,6 +481,7 @@ enum tty_code_code {
 	TTYC_ENACS,
 	TTYC_ENBP,
 	TTYC_ENEKS,
+	TTYC_ENESC,
 	TTYC_ENFCS,
 	TTYC_ENMG,
 	TTYC_FSL,
@@ -1803,6 +1805,7 @@ struct tty_term {
 #define TERM_IMAGE_QUADRANTS 0x200
 #define TERM_IMAGE_SEXTANTS 0x400
 #endif
+#define TERM_NOREPLACE 0x800
 	int		 flags;

 	LIST_ENTRY(tty_term) entry;
@@ -3076,7 +3079,7 @@ void	tty_default_colours(struct grid_cell *, struct window_pane *, u_int *);
 /* tty-term.c */
 extern struct tty_terms tty_terms;
 u_int		 tty_term_ncodes(void);
-void		 tty_term_apply(struct tty_term *, const char *, int);
+void		 tty_term_apply(struct tty_term *, const char *, int, int);
 void		 tty_term_apply_overrides(struct tty_term *);
 struct tty_term *tty_term_create(struct tty *, char *, char **, u_int, char **);
 void		 tty_term_free(struct tty_term *);
@@ -3297,6 +3300,7 @@ void 		 cmdq_print_data(struct cmdq_item *, struct evbuffer *);
 void printflike(2, 3) cmdq_error(struct cmdq_item *, const char *, ...);

 /* cmd-wait-for.c */
+void	cmd_wait_for_client_lost(struct client *);
 void	cmd_wait_for_flush(void);

 /* client.c */
--- a/tty-draw.c
+++ b/tty-draw.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: tty-draw.c,v 1.16 2026/09/21 10:22:31 nicm Exp $ */
+/* $OpenBSD: tty-draw.c,v 1.17 2026/09/22 06:49:47 nicm Exp $ */

 /*
 * Copyright (c) 2026 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -222,7 +222,12 @@ tty_draw_line(struct tty *tty, struct screen *s, u_int px, u_int py, u_int nx,
 	}

 	/* Did the previous line wrap on to this one? */
-	if (py != 0 && atx == 0 && tty->cx >= tty->sx && nx == tty->sx) {
+	if (py != 0 &&
+	    atx == 0 &&
+	    tty->cx >= tty->sx &&
+	    tty->cy != UINT_MAX &&
+	    tty->cy + 1 == aty &&
+	    nx == tty->sx) {
 		gl = grid_get_line(gd, gd->hsize + py - 1);
 		if (gl->flags & GRID_LINE_WRAPPED)
 			wrapped = 1;
--- a/tty-features.c
+++ b/tty-features.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: tty-features.c,v 1.43 2026/08/31 12:41:03 kirill Exp $ */
+/* $OpenBSD: tty-features.c,v 1.45 2026/09/22 14:10:26 nicm Exp $ */

 /*
 * Copyright (c) 2020 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -189,6 +189,18 @@ static const struct tty_feature tty_feature_focus = {
 	0
 };

+/* Terminal supports application escape key mode. */
+static const char *const tty_feature_appesc_capabilities[] = {
+	"Enesc=\\E[?7727h",
+	"Dsesc=\\E[?7727l",
+	NULL
+};
+static const struct tty_feature tty_feature_appesc = {
+	"appesc",
+	tty_feature_appesc_capabilities,
+	0
+};
+
 /* Terminal supports cursor styles. */
 static const char *const tty_feature_cstyle_capabilities[] = {
 	"Ss=\\E[%p1%d q",
@@ -198,7 +210,7 @@ static const char *const tty_feature_cstyle_capabilities[] = {
 static const struct tty_feature tty_feature_cstyle = {
 	"cstyle",
 	tty_feature_cstyle_capabilities,
-	0
+	TERM_NOREPLACE
 };

 /* Terminal supports cursor colours. */
@@ -408,6 +420,7 @@ static const struct tty_feature tty_feature_utf8 = {
 /* Available terminal features. */
 static const struct tty_feature *const tty_features[] = {
 	&tty_feature_256,
+	&tty_feature_appesc,
 	&tty_feature_bpaste,
 	&tty_feature_ccolour,
 	&tty_feature_clipboard,
@@ -576,11 +589,11 @@ tty_apply_features(struct tty_term *term)
 			capability = tf->capabilities;
 			while (*capability != NULL) {
 				log_debug("adding capability: %s", *capability);
-				tty_term_apply(term, *capability, 1);
+				tty_term_apply(term, *capability, 1, tf->flags);
 				capability++;
 			}
 		}
-		term->flags |= tf->flags;
+		term->flags |= (tf->flags & ~TERM_NOREPLACE);
 		if (tf == &tty_feature_utf8)
 			c->flags |= CLIENT_UTF8;
 	}
@@ -603,6 +616,7 @@ tty_default_features(struct client *c, const char *name, u_int version)
 	"256,RGB,bpaste,clipboard,mouse,strikethrough,title"
 		{ .name = "mintty",
 		  .features = TTY_FEATURES_BASE_MODERN_XTERM ","
+			      "appesc,"
 			      "ccolour,"
 			      "cstyle,"
 			      "extkeys,"
@@ -658,6 +672,7 @@ tty_default_features(struct client *c, const char *name, u_int version)
 			      "extkeys,"
 			      "focus,"
 		  	      "hyperlinks,"
+			      "margins,"
 			      "sixel,"
 			      "usstyle"
 		},
@@ -667,6 +682,7 @@ tty_default_features(struct client *c, const char *name, u_int version)
 			      "cstyle,"
 			      "extkeys,"
 			      "focus,"
+			      "margins,"
 			      "overline,"
 			      "hyperlinks,"
 			      "osc7,"
@@ -710,6 +726,22 @@ tty_default_features(struct client *c, const char *name, u_int version)
 			      "cstyle,"
 			      "extkeys,"
 			      "focus"
+		},
+		/*
+		 * Windows Terminal cannot be identified by the XTVERSION
+		 * mechanism used for the other entries above - its
+		 * maintainers have declined to implement it (see
+		 * github.com/microsoft/terminal issue 18382). It is instead
+		 * detected via the WT_SESSION environment variable it sets
+		 * for every child process (tty_term_create(), tty-term.c).
+		 * DECSLRM support was independently confirmed by direct
+		 * (non-tmux) testing; other capabilities have not been
+		 * verified, so only margins is granted here - deliberately
+		 * not the full modern-xterm feature bundle other entries
+		 * get.
+		 */
+		{ .name = "WindowsTerminal",
+		  .features = "margins"
 		}
 	};
 	u_int	i;
--- a/tty-term.c
+++ b/tty-term.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: tty-term.c,v 1.109 2026/08/25 08:37:08 nicm Exp $ */
+/* $OpenBSD: tty-term.c,v 1.111 2026/09/22 14:10:26 nicm Exp $ */

 /*
 * Copyright (c) 2008 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -90,6 +90,7 @@ static const struct tty_term_code_entry tty_term_codes[] = {
 	[TTYC_DL1] = { TTYCODE_STRING, "dl1" },
 	[TTYC_DL] = { TTYCODE_STRING, "dl" },
 	[TTYC_DSEKS] = { TTYCODE_STRING, "Dseks" },
+	[TTYC_DSESC] = { TTYCODE_STRING, "Dsesc" },
 	[TTYC_DSFCS] = { TTYCODE_STRING, "Dsfcs" },
 	[TTYC_DSBP] = { TTYCODE_STRING, "Dsbp" },
 	[TTYC_DSMG] = { TTYCODE_STRING, "Dsmg" },
@@ -101,6 +102,7 @@ static const struct tty_term_code_entry tty_term_codes[] = {
 	[TTYC_ENACS] = { TTYCODE_STRING, "enacs" },
 	[TTYC_ENBP] = { TTYCODE_STRING, "Enbp" },
 	[TTYC_ENEKS] = { TTYCODE_STRING, "Eneks" },
+	[TTYC_ENESC] = { TTYCODE_STRING, "Enesc" },
 	[TTYC_ENFCS] = { TTYCODE_STRING, "Enfcs" },
 	[TTYC_ENMG] = { TTYCODE_STRING, "Enmg" },
 	[TTYC_FSL] = { TTYCODE_STRING, "fsl" },
@@ -362,7 +364,8 @@ tty_term_override_next(const char *s, size_t *offset)
 }

 void
-tty_term_apply(struct tty_term *term, const char *capabilities, int quiet)
+tty_term_apply(struct tty_term *term, const char *capabilities, int quiet,
+    int flags)
 {
 	const struct tty_term_code_entry	*ent;
 	struct tty_code				*code;
@@ -405,6 +408,9 @@ tty_term_apply(struct tty_term *term, const char *capabilities, int quiet)
 			if (strcmp(s, ent->name) != 0)
 				continue;
 			code = &term->codes[i];
+			if ((flags & TERM_NOREPLACE) &&
+			    code->type != TTYCODE_NONE)
+				continue;

 			if (remove) {
 				code->type = TTYCODE_NONE;
@@ -457,7 +463,7 @@ tty_term_apply_overrides(struct tty_term *term)
 		offset = 0;
 		first = tty_term_override_next(s, &offset);
 		if (first != NULL && fnmatch(first, term->name, 0) == 0)
-			tty_term_apply(term, s + offset, 0);
+			tty_term_apply(term, s + offset, 0, 0);
 		a = options_array_next(a);
 	}

@@ -640,6 +646,15 @@ tty_term_create(struct tty *tty, char *name, char **caps, u_int ncaps,
 			tty_parse_client_features(c, "256", ",");
 	}

+	/*
+	 * Windows Terminal cannot be identified by XTVERSION (its
+	 * maintainers have declined to implement it), but it sets
+	 * WT_SESSION for every child process - see the WindowsTerminal
+	 * entry in tty_default_features()'s table (tty-features.c).
+	 */
+	if (environ_find(c->environ, "WT_SESSION") != NULL)
+		tty_default_features(c, "WindowsTerminal", 0);
+
 	/* Apply overrides so any capabilities used for features are changed. */
 	tty_term_apply_overrides(term);

--- a/tty.c
+++ b/tty.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: tty.c,v 1.481 2026/09/21 10:22:31 nicm Exp $ */
+/* $OpenBSD: tty.c,v 1.482 2026/09/22 06:58:06 nicm Exp $ */

 /*
 * Copyright (c) 2007 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -512,8 +512,7 @@ tty_stop_tty(struct tty *tty)
 	if (tty_term_has(tty->term, TTYC_DSBP))
 		tty_raw(tty, tty_term_string(tty->term, TTYC_DSBP));

-	if (tty->term->flags & TERM_VT100LIKE)
-		tty_raw(tty, "\033[?7727l");
+	tty_raw(tty, tty_term_string(tty->term, TTYC_DSESC));
 	tty_raw(tty, tty_term_string(tty->term, TTYC_DSFCS));
 	tty_raw(tty, tty_term_string(tty->term, TTYC_DSEKS));

@@ -583,8 +582,7 @@ tty_update_features(struct tty *tty)
 		tty_puts(tty, tty_term_string(tty->term, TTYC_ENEKS));
 	if (options_get_number(global_options, "focus-events"))
 		tty_puts(tty, tty_term_string(tty->term, TTYC_ENFCS));
-	if (tty->term->flags & TERM_VT100LIKE)
-		tty_puts(tty, "\033[?7727h");
+	tty_puts(tty, tty_term_string(tty->term, TTYC_ENESC));

 	/*
 	 * Features might have changed since the first draw during attach. For