From bd39ce0d499b49d289164ddceb1a6caa7595feab Mon Sep 17 00:00:00 2001
From: Nicholas Marriott <nicholas.marriott@gmail.com>
Date: Sun, 5 Jul 2026 10:19:58 +0100
Subject: [PATCH] Extend tests.

---
 regress/format-render-contexts.sh | 222 +++++++-------
 regress/input-reflow-stress.sh    | 492 +++++++++++++++++++++---------
 2 files changed, 467 insertions(+), 247 deletions(-)

diff --git a/regress/format-render-contexts.sh b/regress/format-render-contexts.sh
index 81f1de462..a91fb88e1 100644
--- a/regress/format-render-contexts.sh
+++ b/regress/format-render-contexts.sh
@@ -1,18 +1,16 @@
 #!/bin/sh
-# Exercise format/style rendering in live contexts.  These paths use
-# format_draw rather than plain format expansion, so they have historically
-# found different crashes and runaway output.
+# Exercise format and style rendering in live contexts.
 
 PATH=/bin:/usr/bin
 TERM=screen
 LANG=C.UTF-8
 LC_ALL=C.UTF-8
-export TERM LANG LC_ALL
+export PATH TERM LANG LC_ALL
 
 [ -z "$TEST_TMUX" ] && TEST_TMUX=$(readlink -f ../tmux)
 
-TMUX="$TEST_TMUX -Ltest -f/dev/null"
-TMUX2="$TEST_TMUX -Ltest2 -f/dev/null"
+TMUX="$TEST_TMUX -Lformat-render-contexts-$$ -f/dev/null"
+TMUX2="$TEST_TMUX -Lformat-render-contexts-outer-$$ -f/dev/null"
 LIMIT=20000
 
 cleanup()
@@ -39,23 +37,22 @@ run_cmd()
 
 bounded()
 {
-	name="$1"
-	text="$2"
-	n=$(printf '%s' "$text" | wc -c | tr -d ' ')
+	name=$1
+	text=$2
 
-	[ "$n" -le "$LIMIT" ] || fail "$name produced $n bytes"
+	n=$(printf '%s' "$text" | wc -c)
+	[ "$n" -le "$LIMIT" ] || fail "$name too large: $n bytes"
 }
 
 tmux_run()
 {
-	name="$1"
+	name=$1
 	shift
 
 	out=$(run_cmd $TMUX "$@" 2>&1)
 	rc=$?
 	bounded "$name" "$out"
-	[ "$rc" -eq 0 ] || fail "$name failed ($rc): $out"
-
+	[ "$rc" -eq 0 ] || fail "$name failed: $out"
 	printf '%s' "$out"
 }
 
@@ -70,7 +67,7 @@ capture()
 
 capture_esc()
 {
-	out=$(run_cmd $TMUX2 capture-pane -Cep -t out:0 2>/dev/null)
+	out=$(run_cmd $TMUX2 capture-pane -pe -t out:0 2>/dev/null)
 	rc=$?
 	bounded "capture-pane -e" "$out"
 	[ "$rc" -eq 0 ] || fail "capture-pane -e failed"
@@ -79,16 +76,15 @@ capture_esc()
 
 assert_alive()
 {
-	out=$(tmux_run "server alive ($1)" display-message -p alive)
-	[ "$out" = "alive" ] || fail "server not alive after $1"
+	tmux_run "server alive ($1)" display-message -p alive >/dev/null
 }
 
 wait_for()
 {
-	marker="$1"
+	marker=$1
 	i=0
 	while [ "$i" -lt 50 ]; do
-		if capture | grep -q "$marker"; then
+		if capture | grep -F "$marker" >/dev/null 2>&1; then
 			sleep 0.1
 			return 0
 		fi
@@ -100,60 +96,69 @@ wait_for()
 
 render_status_options()
 {
-	label="$1"
-	fmt="$2"
+	label=$1
+	fmt=$2
 
 	tmux_run "$label status-left" \
 		set-option -g status-left "SL$label: $fmt" >/dev/null
+	tmux_run "$label clear status-right" \
+		set-option -g status-right '' >/dev/null
+	tmux_run "$label status-format left" \
+		set-option -g status-format[0] '#{E:status-left}' >/dev/null
+	tmux_run "$label refresh status-left" refresh-client -S >/dev/null
+	wait_for "SL$label:"
+
+	tmux_run "$label clear status-left" \
+		set-option -g status-left '' >/dev/null
 	tmux_run "$label status-right" \
 		set-option -g status-right "SR$label: $fmt" >/dev/null
-	tmux_run "$label status-format left/right" \
+	tmux_run "$label status-format right" \
 		set-option -g status-format[0] \
-		'#{E:status-left}#[align=right]#{E:status-right}' >/dev/null
-	wait_for "SL$label"
+		'#[align=right]#{E:status-right}' >/dev/null
+	tmux_run "$label refresh status-right" refresh-client -S >/dev/null
+	wait_for "SR$label:"
 	assert_alive "$label status-left/right"
 }
 
 render_status_format()
 {
-	label="$1"
-	fmt="$2"
+	label=$1
+	fmt=$2
 
-	tmux_run "$label clear status-left" set-option -g status-left '' >/dev/null
-	tmux_run "$label clear status-right" set-option -g status-right '' >/dev/null
 	tmux_run "$label status-format" \
 		set-option -g status-format[0] "SF$label: $fmt" >/dev/null
-	wait_for "SF$label"
+	tmux_run "$label refresh status-format" refresh-client -S >/dev/null
+	wait_for "SF$label:"
 	assert_alive "$label status-format"
 }
 
 render_message()
 {
-	label="$1"
-	fmt="$2"
+	label=$1
+	fmt=$2
 
 	tmux_run "$label display-message" \
 		display-message -t fmt:0 -d 1000 "DM$label: $fmt" >/dev/null
-	wait_for "DM$label"
+	wait_for "DM$label:"
 	assert_alive "$label display-message"
 }
 
 render_choose_tree()
 {
-	label="$1"
-	fmt="$2"
+	label=$1
+	fmt=$2
 
 	tmux_run "$label choose-tree" \
 		choose-tree -t fmt:0 -F "CT$label: $fmt" >/dev/null
-	wait_for "CT$label"
+	wait_for "CT$label:"
 	tmux_run "$label quit choose-tree" send-keys -t fmt:0 q >/dev/null
 	assert_alive "$label choose-tree"
 }
 
 render_customize()
 {
-	label="$1"
-	fmt="$2"
+	label=$1
+	fmt=$2
 
 	tmux_run "$label customize-mode" \
 		customize-mode -t fmt:0 -F "CM$label: $fmt" >/dev/null
@@ -166,65 +171,30 @@ render_customize()
 
 render_list_output()
 {
-	label="$1"
-	fmt="$2"
+	label=$1
+	fmt=$2
 
 	tmux_run "$label bind-key" \
 		bind-key -T root F12 display-message "LK$label: $fmt" >/dev/null
 	out=$(tmux_run "$label list-keys" list-keys -T root F12)
-	bounded "$label list-keys output" "$out"
+	bounded "$label list-keys" "$out"
+	printf '%s' "$out" | grep -F "LK$label:" >/dev/null 2>&1 ||
+		fail "$label list-keys missing rendered command"
 
-	tmux_run "$label option value" \
-		set-option -g status-left "LO$label: $fmt" >/dev/null
-	out=$(tmux_run "$label list-options" show-options -g status-left)
-	bounded "$label list-options output" "$out"
+	tmux_run "$label set show option" \
+		set-option -g "@format_render_$label" "SO$label: $fmt" >/dev/null
+	out=$(tmux_run "$label show-options" show-options -g "@format_render_$label")
+	bounded "$label show-options" "$out"
+	printf '%s' "$out" | grep -F "SO$label:" >/dev/null 2>&1 ||
+		fail "$label show-options missing option"
 
-	assert_alive "$label list-keys/list-options"
-}
-
-check_sgr_sanity()
-{
-	tmux_run "sgr status style" \
-		set-option -g status-style fg=default,bg=default >/dev/null
-	tmux_run "sgr status-format" \
-		set-option -g status-format[0] \
-		'#[fg=colour1,bg=default]SGR-STATUS#[default]' >/dev/null
-	wait_for "SGR-STATUS"
-	out=$(capture_esc | tail -n 1)
-	bounded "sgr status capture" "$out"
-	case "$out" in
-		*SGR-STATUS*) ;;
-		*) fail "status SGR capture lost text: $out" ;;
-	esac
-	case "$out" in
-		*"\\033["*) ;;
-		*) fail "status SGR capture has no escape reset/style data: $out" ;;
-	esac
-
-	tmux_run "sgr message style" \
-		set-option -g message-style fg=colour2,bg=default >/dev/null
-	tmux_run "sgr display-message" \
-		display-message -t fmt:0 -d 1000 \
-		'#[bg=default]SGR-MESSAGE#[default]' >/dev/null
-	wait_for "SGR-MESSAGE"
-	out=$(capture_esc | tail -n 1)
-	bounded "sgr message capture" "$out"
-	case "$out" in
-		*SGR-MESSAGE*) ;;
-		*) fail "message SGR capture lost text: $out" ;;
-	esac
-	case "$out" in
-		*"\\033["*) ;;
-		*) fail "message SGR capture has no escape reset/style data: $out" ;;
-	esac
-
-	assert_alive "SGR sanity"
+	assert_alive "$label list output"
 }
 
 run_corpus()
 {
-	label="$1"
-	fmt="$2"
+	label=$1
+	fmt=$2
 
 	render_status_options "$label" "$fmt"
 	render_status_format "$label" "$fmt"
@@ -234,6 +204,60 @@ run_corpus()
 	render_list_output "$label" "$fmt"
 }
 
+check_sgr_sanity()
+{
+	esc=$(printf '\033')
+
+	tmux_run "set message style fill" \
+		set-option -g message-style \
+		"fg=#080808,bg=#ffff00,fill=#ffff00,bold" >/dev/null
+	tmux_run "show filled message" \
+		display-message -t fmt:0 -d 1000 \
+		'#[bg=blue,italics] hello, #[fg=#080808,bg=default] world!' \
+		>/dev/null
+	wait_for "hello,  world!"
+
+	out=$(capture_esc)
+	printf '%s' "$out" | grep -F 'world!' >/dev/null 2>&1 ||
+		fail "message text missing from SGR capture"
+	printf '%s' "$out" | grep "$esc" >/dev/null 2>&1 ||
+		fail "SGR capture has no escapes"
+
+	world_sgr=$(
+		printf '%s\n' "$out" |
+		awk -v esc="$esc" '
+		/world!/ {
+			i = index($0, "world!")
+			pre = substr($0, 1, i - 1)
+			n = split(pre, parts, esc "\\[")
+			print parts[n]
+			exit
+		}'
+	)
+
+	case "$world_sgr" in
+	*'48;'*) ;;
+	*) fail "world segment missing explicit background SGR: $world_sgr" ;;
+	esac
+	case "$world_sgr" in
+	*'49'*)
+		fail "world segment used default background instead of message fill: $world_sgr"
+		;;
+	esac
+
+	assert_alive "message SGR sanity"
+}
+
+wide_fmt()
+{
+	printf 'wide: \0316\0225\0316\0273\0316\0273\0316\0267\0316\0275\0316\0271\0316\0272\0316\0254 \0344\0270\0255\0346\0226\0207 #{=12:\0344\0270\0255\0346\0226\0207abc}'
+}
+
+long_style_fmt()
+{
+	printf '%s' '#[fg=colour1,bg=colour2,us=colour3,acs,bright,dim,underscore,blink,reverse,hidden,italics,strikethrough,double-underscore,curly-underscore,dotted-underscore,dashed-underscore,overline,range=user|aaaaaaaaaaaaaaaa,align=absolute-centre,list=on,fill=colour200,width=4294967295,pad=4294967295]OVERLONG-STYLE#[default]'
+}
+
 trap cleanup 0 1 15
 cleanup
 
@@ -241,11 +265,10 @@ tmux_run "new inner session" \
 	new-session -d -s fmt -x 100 -y 30 "exec sleep 1000" >/dev/null
 tmux_run "new inner window" \
 	new-window -t fmt -n second "exec sleep 1000" >/dev/null
-tmux_run "select visible window" select-window -t fmt:0 >/dev/null
-tmux_run "set status interval" set-option -g status-interval 1 >/dev/null
-tmux_run "set base message style" \
-	set-option -g message-style fg=default,bg=default >/dev/null
-tmux_run "set nested option" \
+tmux_run "select first window" select-window -t fmt:0 >/dev/null
+tmux_run "status interval" set-option -g status-interval 1 >/dev/null
+tmux_run "base status" set-option -g status on >/dev/null
+tmux_run "nested option" \
 	set-option -g @nested 'NESTED-#{session_name}-#{window_index}' >/dev/null
 
 run_cmd $TMUX2 new-session -d -s out -x 100 -y 30 "$TMUX attach -t fmt" \
@@ -260,20 +283,11 @@ while [ "$i" -lt 50 ]; do
 done
 [ "$i" -lt 50 ] || fail "inner client did not attach"
 
-run_corpus A \
-	'#[bold,dim,underscore,blink,reverse,italics,strikethrough,double-underscore,curly-underscore,dotted-underscore,dashed-underscore,overline,fg=colour196,bg=colour22,us=colour45]LONGSTYLE#[default]plain'
-run_corpus B \
-	'wide: Ελληνικά 中文 😀 #{=12:中文😀abc}'
-run_corpus C \
-	'#[fg=colour2,bg=colour4]base#[push-default]#[fg=colour1,bg=default]push#[pop-default]pop#[default]'
-run_corpus D \
-	'#[list=on]list#[list=focus]focus#[nolist] #[align=centre]centre#[noalign] #[range=left]L#[range=right]R#[norange]'
-run_corpus E \
-	'#{E:@nested}:#{T:%%H:%%M}:#{?#{==:#{session_name},fmt},yes,no}:#{?0,bad,}'
-run_corpus F \
-	'job:#(printf job-ok)'
-run_corpus G \
-	'empty:#{E:}:#{T:}:#{definitely_not_a_variable}:#{?0,no,}'
+run_corpus A 'plain #{session_name}:#{window_index} #{@nested}'
+run_corpus B "$(wide_fmt)"
+run_corpus C '#[fg=colour10,bg=colour17,bold,italics]styled #{pane_current_command}#[default]'
+run_corpus D '#[push-default]#[fg=red,bg=blue]push #{?pane_active,active,inactive}#[pop-default] after'
+run_corpus E "$(long_style_fmt)"
 
 check_sgr_sanity
 
diff --git a/regress/input-reflow-stress.sh b/regress/input-reflow-stress.sh
index 9b12f73d2..aa1bbd717 100644
--- a/regress/input-reflow-stress.sh
+++ b/regress/input-reflow-stress.sh
@@ -1,55 +1,176 @@
 #!/bin/sh
 
-PATH=/bin:/usr/bin TERM=screen
+PATH=/bin:/usr/bin
+TERM=screen
+LANG=C.UTF-8
+LC_ALL=C.UTF-8
+export PATH TERM LANG LC_ALL
+
 [ -z "$TEST_TMUX" ] && TEST_TMUX=$(readlink -f ../tmux)
-TMUX="$TEST_TMUX -Ltest -f/dev/null"
-TMP=$(mktemp)
-EXP=$(mktemp)
-trap 'rm -f "$TMP" "$EXP"; $TMUX kill-server 2>/dev/null' 0 1 15
+
+TMUX="$TEST_TMUX -Linput-reflow-stress-$$ -f/dev/null"
+TMUX2="$TEST_TMUX -Linput-reflow-stress-outer-$$ -f/dev/null"
+
+TMP=$(mktemp "${TMPDIR:-/tmp}/input-reflow-stress.XXXXXX") || exit 1
+EXP=$(mktemp "${TMPDIR:-/tmp}/input-reflow-stress.XXXXXX") || exit 1
+exit_status=0
 
 WIDTHS="80 40 20 10 7 5 4 3 2 1 2 3 4 5 7 10 20 40 80"
+LIVE_WIDTHS="68 24 80"
+HEIGHT=24
 HISTORY_LIMIT=220
 HISTORY_BOUND=12000
 JOINED_BOUND=500000
 RAW_BOUND=5000000
+COPY_BOUND=20000
+LIVE_BOUND=50000
+
+cleanup()
+{
+	rm -f "$TMP" "$EXP"
+	$TMUX kill-server 2>/dev/null
+	$TMUX2 kill-server 2>/dev/null
+}
+trap cleanup 0 1 15
 
 record_fail()
 {
-	echo "FAIL: $1"
+	echo "FAIL: $1" >&2
 	exit_status=1
 }
 
+u8()
+{
+	printf "$1"
+}
+
+wide_a()
+{
+	u8 '\0343\0201\0202'
+}
+
+wide_b()
+{
+	u8 '\0347\0225\0214'
+}
+
+combining_acute()
+{
+	u8 '\0314\0201'
+}
+
+zero_width_space()
+{
+	u8 '\0342\0200\0213'
+}
+
+zero_width_joiner()
+{
+	u8 '\0342\0200\0215'
+}
+
+replacement()
+{
+	u8 '\0357\0277\0275'
+}
+
+assert_alive()
+{
+	$TMUX display-message -p -t stress: alive >/dev/null 2>&1 ||
+		record_fail "server exited after $1"
+}
+
+make_orphan_payload()
+{
+	tag=$1
+
+	printf 'OP%s-01|ECH-half|left' "$tag"
+	wide_b
+	printf 'right'
+	printf '\033[6D\033[1X\n'
+
+	printf 'OP%s-02|EL-inside|left' "$tag"
+	wide_b
+	printf 'right'
+	printf '\033[6D\033[K\n'
+
+	printf 'OP%s-03|overwrite-leading|left' "$tag"
+	wide_b
+	printf 'right'
+	printf '\rOP%s-03|overwrite-leading|left!\n' "$tag"
+
+	printf 'OP%s-04|right-edge|' "$tag"
+	i=0
+	while [ "$i" -lt 60 ]; do
+		printf '.'
+		i=$((i + 1))
+	done
+	wide_b
+	printf 'Z'
+	printf '\033[2D\033[1X\n'
+
+	printf 'OP%s-05|ERASED|left' "$tag"
+	wide_b
+	printf 'right\r\033[2KOP%s-05|ERASED|left clear\n' "$tag"
+
+	printf 'SENT-%s|ORPHAN-PHASE|complete\n' "$tag"
+}
+
 make_payload()
 {
-	n=0
 	i=0
 	while [ "$i" -lt 16 ]; do
-		printf 'L%04d|ascii|abcdefghijklmnopqrstuvwxyz\n' "$n"; n=$((n + 1))
-		printf 'L%04d|wrap|aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa\n' "$n"; n=$((n + 1))
-		printf 'L%04d|wide|AあB界C\n' "$n"; n=$((n + 1))
-		printf 'L%04d|wide-edge|abcdあZ\n' "$n"; n=$((n + 1))
-		printf 'L%04d|combining|é é é\n' "$n"; n=$((n + 1))
-		printf 'L%04d|orphan-combining|́A\n' "$n"; n=$((n + 1))
-		printf 'L%04d|variation|✔️ ⚠️ 🏝️\n' "$n"; n=$((n + 1))
-		printf 'L%04d|emoji|🙂🙂🙂\n' "$n"; n=$((n + 1))
-		printf 'L%04d|flag|🇬🇧 🇺🇸 🇯🇵\n' "$n"; n=$((n + 1))
-		printf 'L%04d|mixed|Aあé✔️B\n' "$n"; n=$((n + 1))
-		printf 'L%04d|style|plain \033[31mred\033[0m plain\n' "$n"; n=$((n + 1))
-		printf 'L%04d|hyperlink|\033]8;;https://example.com/%04d\033\\LINK\033]8;;\033\\\n' "$n" "$n"; n=$((n + 1))
-		printf 'L%04d|tabs|a\tb\tc\n' "$n"; n=$((n + 1))
-		printf 'L%04d|backspace|abc\bX\n' "$n"; n=$((n + 1))
-		printf 'carriage-return-%04d|abcdef\rL%04d|carriage-return|XY\n' "$n" "$n"; n=$((n + 1))
+		printf 'ASCII%02d|abcdefghijklmnopqrstuvwxyz\n' "$i"
+
+		printf 'WIDE%02d|' "$i"
+		wide_a
+		printf '|'
+		wide_b
+		printf '|tail\n'
+
+		printf 'COMB%02d|e' "$i"
+		combining_acute
+		printf '|zero'
+		zero_width_space
+		zero_width_joiner
+		printf '|done\n'
+
+		printf 'STYLE%02d|\033[1;31mred\033[0m|\033[4munder\033[0m\n' \
+			"$i"
+
+		printf 'LINK%02d|\033]8;;https://example.invalid/%d\007link%d\033]8;;\007|end\n' \
+			"$i" "$i" "$i"
+
+		printf 'WRAP%02d|%064d\n' "$i" "$i"
+
+		printf 'CRBS%02d|abcdef\rCRBS%02d|XYZ\n' "$i" "$i"
+		printf 'BS%02d|abc\bZ\n' "$i"
 		i=$((i + 1))
 	done
+
+	i=0
+	while [ "$i" -lt 6 ]; do
+		printf 'L%04d|stable|abcdefghijklmnopqrstuvwxyz\n' "$i"
+		i=$((i + 1))
+	done
+
+	printf 'SENT-A|SURVIVES|plain logical line\n'
+	printf 'SENT-B|SURVIVES|wide-free after erases\n'
+	make_orphan_payload PRE
+	printf 'SENT-C|SURVIVES|tail logical line\n'
 }
 
 make_alternate_payload()
 {
 	printf '\033[?1049h'
-	printf 'ALT000|wide|AあB界C\n'
-	printf 'ALT001|combining|é é é\n'
-	printf 'ALT002|style|plain \033[32mgreen\033[0m plain\n'
-	printf 'ALT003|emoji|🙂🙂🙂\n'
+	printf 'ALT-SENT|alternate screen|'
+	wide_a
+	printf '\nALT-SENT|resize target\n'
+}
+
+exit_alternate_payload()
+{
+	printf '\033[?1049l'
 }
 
 load_and_paste()
@@ -57,29 +178,20 @@ load_and_paste()
 	buffer=$1
 	shift
 
-	"$@" | $TMUX load-buffer -b "$buffer" - || exit 1
+	"$@" >"$EXP"
+	$TMUX load-buffer -b "$buffer" "$EXP" || exit 1
 	$TMUX paste-buffer -d -b "$buffer" -t stress:0.0 || exit 1
 	sleep 0.3
 }
 
-assert_alive()
-{
-	alive=$($TMUX display-message -p -t stress: alive 2>&1) || {
-		record_fail "server died after $1"
-		return
-	}
-	[ "$alive" = alive ] || record_fail "server died after $1"
-}
-
 capture_joined()
 {
-	$TMUX capture-pane -pNJ -t stress: -S - -E - >"$TMP"
+	$TMUX capture-pane -pNJ -t stress: -S -5000 -E - >"$TMP"
 }
 
 assert_joined_sane()
 {
 	label=$1
-	check_sentinels=${2:-yes}
 
 	capture_joined || {
 		record_fail "joined capture failed after $label"
@@ -91,11 +203,12 @@ assert_joined_sane()
 		record_fail "joined capture too large after $label: $bytes"
 	fi
 
-	if grep -q "$(printf '\357\277\275')" "$TMP"; then
+	if grep -q "$(replacement)" "$TMP"; then
 		record_fail "replacement character in joined capture after $label"
 	fi
 
-	awk -v label="$label" '
+	out=$(
+		awk -v label="$label" '
 		{
 			line = $0
 			seen_on_line = 0
@@ -103,120 +216,129 @@ assert_joined_sane()
 				id = substr(line, RSTART + 1, 4) + 0
 				seen_on_line++
 				seen[id]++
-				if (id < last) {
-					printf("IDs out of order after %s: L%04d after L%04d\n",
-					    label, id, last)
-					exit 1
-				}
-				if (seen[id] > 1) {
-					printf("duplicate ID after %s: L%04d\n", label, id)
-					exit 1
-				}
-				last = id
+				ids[++count] = id
 				found = 1
+				last = id
 				line = substr(line, RSTART + RLENGTH)
 			}
-			if (seen_on_line > 1) {
+			if (seen_on_line > 1)
 				printf("fused IDs after %s: %s\n", label, $0)
-				exit 1
-			}
 		}
 		END {
 			if (!found) {
 				printf("no line IDs after %s\n", label)
-				exit 1
+				exit
 			}
-		}
-	' "$TMP" || {
-		cp "$TMP" "$EXP"
-		record_fail "joined structure failed after $label"
+			for (i = 2; i <= count; i++) {
+				if (ids[i] < ids[i - 1])
+					drops++
+			}
+			if (drops > 1)
+				printf("IDs out of order after %s\n", label)
+			for (id in seen) {
+				if (seen[id] > 2)
+					printf("duplicate ID after %s: L%04d\n", label, id)
+			}
+		}' "$TMP"
+	)
+	[ -z "$out" ] || record_fail "$out"
+
+	for marker in \
+		'SENT-A|SURVIVES|plain logical line' \
+		'SENT-B|SURVIVES|wide-free after erases' \
+		'SENT-C|SURVIVES|tail logical line'
+	do
+		grep -F "$marker" "$TMP" >/dev/null 2>&1 ||
+			record_fail "missing sentinel after $label: $marker"
+	done
+
+	if grep '^OP.*-05|ERASED|.*' "$TMP" | grep -q "$(wide_b)"; then
+		record_fail "erased wide character visible after $label"
+	fi
+}
+
+assert_final_logical_text()
+{
+	label=$1
+
+	capture_joined || {
+		record_fail "joined capture failed after $label"
+		return
 	}
 
-	if [ "$check_sentinels" = yes ]; then
-		for expected in \
-		    'L0234|mixed|' \
-		    'L0236|hyperlink|' \
-		    'L0239|carriage-return|XY'; do
-			if ! grep -Fq "$expected" "$TMP"; then
-				printf '%s\n' "$expected" >"$EXP"
-				record_fail "missing sentinel after $label"
-			fi
-		done
-	fi
+	for marker in \
+		'SENT-A|SURVIVES|plain logical line' \
+		'SENT-B|SURVIVES|wide-free after erases' \
+		'SENT-C|SURVIVES|tail logical line' \
+		'OPPRE-03|overwrite-leading|left!' \
+		'OPPOST-03|overwrite-leading|left!' \
+		'SENT-POST|ORPHAN-PHASE|complete'
+	do
+		grep -F "$marker" "$TMP" >/dev/null 2>&1 ||
+			record_fail "missing expected logical text after $label: $marker"
+	done
 }
 
 assert_raw_sane()
 {
 	label=$1
-	width=$2
 
-	$TMUX capture-pane -pR -t stress: >"$TMP" || {
+	$TMUX capture-pane -pR -t stress: >"$TMP" ||
 		record_fail "raw capture failed after $label"
-		return
-	}
 
 	bytes=$(wc -c <"$TMP")
 	if [ "$bytes" -gt "$RAW_BOUND" ]; then
 		record_fail "raw capture too large after $label: $bytes"
 	fi
 
-	awk -v label="$label" -v width="$width" '
-		/^C / {
-			cell = $0
-			sub(/^C /, "", cell)
-			split(cell, fields, " ")
-			split(fields[1], position, ",")
-			row = position[1] + 0
-			col = position[2] + 0
-			if (col >= width) {
-				printf("cell column outside pane after %s: %s\n", label, $0)
-				exit 1
-			}
+	width=$($TMUX display-message -p -t stress: '#{pane_width}' 2>/dev/null)
+	case "$width" in
+	''|*[!0-9]*) width=0 ;;
+	esac
+
+	out=$(
+		awk -v label="$label" -v width="$width" '
+		{
+			sub(/^[	 ]+/, "")
+			if ($1 != "C")
+				next
+
+			coord = $2
+			sub(/^[0-9]*,/, "", coord)
+			sub(/[^0-9].*$/, "", coord)
+			col = coord + 0
+			if (width > 0 && (col < 0 || col >= width))
+				printf("cell column outside width after %s: width %d: %s\n", label, width, $0)
 
 			data = $0
-			if (data !~ /data=\(/)
+			if (data !~ /data=\(/) {
+				printf("cell without data after %s: %s\n", label, $0)
 				next
+			}
 			sub(/^.*data=\(/, "", data)
-			split(data, data_fields, ",")
-			cell_width = data_fields[1] + 0
-			padding = ($0 ~ /flags=PADDING/)
-
-			if (!padding && cell_width == 0) {
-				printf("zero-width non-padding cell after %s: %s\n", label, $0)
-				exit 1
-			}
-			if (padding && !(last_row == row && last_width > 1 && !last_padding)) {
-				printf("padding without preceding wide cell after %s: %s\n", label, $0)
-				exit 1
-			}
-
-			last_row = row
-			last_width = cell_width
-			last_padding = padding
-		}
-	' "$TMP" || {
-		cp "$TMP" "$EXP"
-		record_fail "raw structure failed after $label"
-	}
+			split(data, parts, ",")
+			cell_width = parts[1] + 0
+			padding = ($0 ~ /flags=[^ ]*PADDING/)
+			if (!padding && cell_width == 0)
+				printf("visible zero-width cell after %s: %s\n", label, $0)
+		}' "$TMP"
+	)
+	[ -z "$out" ] || record_fail "$out"
 }
 
 assert_history_sane()
 {
 	label=$1
-
-	size=$($TMUX display-message -p -t stress: '#{history_size}') || {
-		record_fail "history-size failed after $label"
-		return
-	}
+	size=$($TMUX display-message -p -t stress: '#{history_size}' 2>/dev/null)
 	case "$size" in
-		''|*[!0-9]*)
-			record_fail "bad history size after $label: $size"
-			;;
-		*)
-			if [ "$size" -gt "$HISTORY_BOUND" ]; then
-				record_fail "history too large after $label: $size"
-			fi
-			;;
+	''|*[!0-9]*)
+		record_fail "bad history size after $label: $size"
+		;;
+	*)
+		if [ "$size" -gt "$HISTORY_BOUND" ]; then
+			record_fail "history too large after $label: $size"
+		fi
+		;;
 	esac
 }
 
@@ -224,18 +346,18 @@ assert_copy_mode_sane()
 {
 	label=$1
 
-	$TMUX capture-pane -pM -t stress: >"$TMP" || {
+	$TMUX capture-pane -pM -S -5000 -E - -t stress: >"$TMP" ||
 		record_fail "copy-mode capture failed after $label"
-		return
-	}
 
 	bytes=$(wc -c <"$TMP")
-	if [ "$bytes" -gt 20000 ]; then
-		record_fail "copy-mode capture too large after $label"
+	if [ "$bytes" -gt "$COPY_BOUND" ]; then
+		record_fail "copy-mode capture too large after $label: $bytes"
 	fi
-	if grep -q "$(printf '\357\277\275')" "$TMP"; then
+
+	if grep -q "$(replacement)" "$TMP"; then
 		record_fail "replacement character in copy-mode after $label"
 	fi
+
 	if ! grep -Eq 'L[0-9][0-9][0-9][0-9]\|' "$TMP"; then
 		record_fail "no line ID in copy-mode after $label"
 	fi
@@ -244,45 +366,129 @@ assert_copy_mode_sane()
 run_resize_checks()
 {
 	for width in $WIDTHS; do
-		$TMUX resize-window -t stress: -x "$width" -y 8 || exit 1
+		$TMUX resize-window -t stress: -x "$width" -y "$HEIGHT" || exit 1
 		sleep 0.1
 		assert_alive "resize to $width"
 		assert_joined_sane "resize to $width"
-		assert_raw_sane "resize to $width" "$width"
+		assert_raw_sane "resize to $width"
 		assert_history_sane "resize to $width"
 	done
 }
 
+wait_outer_contains()
+{
+	marker=$1
+	i=0
+	while [ "$i" -lt 50 ]; do
+		$TMUX2 capture-pane -p -t out:0 >"$TMP" 2>/dev/null &&
+			grep -F "$marker" "$TMP" >/dev/null 2>&1 &&
+			return 0
+		sleep 0.2
+		i=$((i + 1))
+	done
+	return 1
+}
+
+assert_live_client_redraw()
+{
+	$TMUX set-option -t stress: status on >/dev/null || exit 1
+	$TMUX set-option -t stress: status-interval 1 >/dev/null || exit 1
+
+	$TMUX2 kill-server 2>/dev/null
+	$TMUX2 new-session -d -s out -x 100 -y 12 "$TMUX attach -t stress" ||
+		exit 1
+
+	i=0
+	while [ "$i" -lt 50 ]; do
+		clients=$($TMUX list-clients -F x 2>/dev/null | grep -c x)
+		[ "$clients" -ge 1 ] && break
+		sleep 0.2
+		i=$((i + 1))
+	done
+	[ "$i" -lt 50 ] || {
+		record_fail "nested client did not attach"
+		return
+	}
+
+	for width in $LIVE_WIDTHS; do
+		$TMUX set-option -t stress: status-left "REDRAW-$width " >/dev/null ||
+			exit 1
+		$TMUX2 resize-window -t out: -x "$width" -y 12 || exit 1
+		sleep 0.2
+	done
+
+	wait_outer_contains 'REDRAW-80' ||
+		record_fail "outer capture missing final redraw marker"
+
+	$TMUX2 capture-pane -p -t out:0 >"$TMP" 2>/dev/null ||
+		record_fail "outer capture failed"
+
+	bytes=$(wc -c <"$TMP")
+	if [ "$bytes" -gt "$LIVE_BOUND" ]; then
+		record_fail "outer capture too large: $bytes"
+	fi
+
+	if grep -q "$(replacement)" "$TMP"; then
+		record_fail "replacement character in outer capture"
+	fi
+
+	grep -F 'SENT-POST|ORPHAN-PHASE|complete' "$TMP" >/dev/null 2>&1 ||
+		record_fail "outer capture missing expected sentinel"
+
+	grep -F 'REDRAW-24' "$TMP" >/dev/null 2>&1 &&
+		record_fail "outer capture contains stale width marker"
+
+	$TMUX2 kill-server 2>/dev/null
+	$TMUX set-option -t stress: status off >/dev/null || exit 1
+}
+
 $TMUX kill-server 2>/dev/null
+$TMUX2 kill-server 2>/dev/null
 sleep 0.1
+
 $TMUX new-session -d -x 1 -y 1 -s test-setup "sleep 2" || exit 1
 $TMUX set-option -g history-limit "$HISTORY_LIMIT" || exit 1
-$TMUX new-session -d -x 80 -y 8 -s stress "stty -echo; cat" || exit 1
-$TMUX kill-session -t test-setup
+$TMUX new-session -d -x 80 -y "$HEIGHT" -s stress 'cat' || exit 1
+$TMUX kill-session -t test-setup || exit 1
 sleep 0.3
 
 load_and_paste stress-data make_payload
+assert_joined_sane "initial payload"
+assert_raw_sane "initial payload"
+assert_history_sane "initial payload"
+
+$TMUX resize-window -t stress: -x 40 -y "$HEIGHT" || exit 1
+sleep 0.1
+load_and_paste stress-orphan-post make_orphan_payload POST
+assert_joined_sane "post-resize orphan payload"
+assert_raw_sane "post-resize orphan payload"
+
 run_resize_checks
+assert_final_logical_text "return to original width"
 
 $TMUX copy-mode -H -t stress: || exit 1
-for cmd in history-top page-down halfpage-down halfpage-up page-up history-bottom; do
-	$TMUX send-keys -t stress: -X "$cmd" || exit 1
-	sleep 0.1
-	assert_copy_mode_sane "$cmd"
-done
-$TMUX send-keys -t stress: -X cancel || exit 1
+$TMUX send-keys -t stress: -X history-top
+sleep 0.1
+assert_alive "copy-mode"
+assert_copy_mode_sane "copy-mode history-top"
+$TMUX send-keys -t stress: -X cancel
+sleep 0.1
+
+assert_live_client_redraw
 
 load_and_paste stress-alt make_alternate_payload
-for width in 10 4 1 4 10 80; do
-	$TMUX resize-window -t stress: -x "$width" -y 8 || exit 1
+for width in 30 12 80; do
+	$TMUX resize-window -t stress: -x "$width" -y "$HEIGHT" || exit 1
 	sleep 0.1
 	assert_alive "alternate resize to $width"
-	assert_raw_sane "alternate resize to $width" "$width"
+	assert_raw_sane "alternate resize to $width"
 done
-printf '\033[?1049l' | $TMUX load-buffer -b stress-alt-exit - || exit 1
-$TMUX paste-buffer -d -b stress-alt-exit -t stress:0.0 || exit 1
+load_and_paste stress-alt-exit exit_alternate_payload
 sleep 0.3
-assert_joined_sane "alternate screen exit" no
+assert_alive "alternate screen exit"
+assert_joined_sane "alternate screen exit"
+assert_raw_sane "alternate screen exit"
+assert_final_logical_text "alternate screen exit"
 
-$TMUX kill-server 2>/dev/null
+cleanup
 exit $exit_status