From 24cde9e0eb9c3162fb413050e24553d3b8093a41 Mon Sep 17 00:00:00 2001
From: Nicholas Marriott <nicholas.marriott@gmail.com>
Date: Fri, 2 Oct 2026 16:13:12 +0100
Subject: [PATCH] Test for 5613.

---
 regress/display-message-client.sh | 66 +++++++++++++++++++++++++++++++
 1 file changed, 66 insertions(+)
 create mode 100755 regress/display-message-client.sh

diff --git a/regress/display-message-client.sh b/regress/display-message-client.sh
new file mode 100755
index 000000000..c0f52c257
--- /dev/null
+++ b/regress/display-message-client.sh
@@ -0,0 +1,66 @@
+#!/bin/sh
+
+# display-message -c must take the client formats from the given client, even
+# when it is attached to a different session from the target pane.
+
+PATH=/bin:/usr/bin
+TERM=screen
+LC_ALL=C.UTF-8
+export PATH TERM LC_ALL
+
+[ -z "$TEST_TMUX" ] && TEST_TMUX=$(readlink -f ../tmux)
+INNER="$TEST_TMUX -LtestI$$ -f/dev/null"
+OUTER="$TEST_TMUX -LtestO$$ -f/dev/null"
+
+fail()
+{
+	echo "$*" >&2
+	exit 1
+}
+
+cleanup()
+{
+	$OUTER kill-server 2>/dev/null
+	$INNER kill-server 2>/dev/null
+}
+trap cleanup 0 1 15
+
+cleanup
+$INNER new-session -d -s one -x40 -y10 'exec sleep 100' || exit 1
+$INNER new-session -d -s two -x40 -y10 'exec sleep 100' || exit 1
+$INNER set-option -g status off || exit 1
+
+# Each client has a distinct TERM so that client_termname identifies it.
+attach()
+{
+	echo "env -i PATH=/bin:/usr/bin TERM=$1 LC_ALL=C.UTF-8 $TEST_TMUX -LtestI$$ -f/dev/null attach-session -t $2"
+}
+$OUTER new-session -d -s outer -x40 -y10 "$(attach screen one)" || exit 1
+$OUTER new-window -d "$(attach xterm two)" || exit 1
+$OUTER set-option -g status off || exit 1
+
+i=0
+while [ "$i" -lt 50 ]; do
+	n=$($INNER list-clients -F '#{client_name}' 2>/dev/null|wc -l)
+	[ "$n" -eq 2 ] && break
+	sleep 0.1
+	i=$((i + 1))
+done
+[ "$i" -lt 50 ] || fail "clients did not attach"
+
+c1=$($INNER list-clients -F '#{client_name}' -f '#{==:#{client_termname},screen}')
+c2=$($INNER list-clients -F '#{client_name}' -f '#{==:#{client_termname},xterm}')
+[ -n "$c1" ] && [ -n "$c2" ] || fail "could not find both clients"
+
+# The target is in session two, but the client is the one in session one.
+term=$($INNER display-message -c "$c1" -t two: -p '#{client_termname}')
+[ "$term" = screen ] || fail "client_termname was '$term', not screen"
+
+# The session formats still come from the target.
+session=$($INNER display-message -c "$c1" -t two: -p '#{session_name}')
+[ "$session" = two ] || fail "session_name was '$session', not two"
+
+term=$($INNER display-message -c "$c2" -t one: -p '#{client_termname}')
+[ "$term" = xterm ] || fail "client_termname was '$term', not xterm"
+
+exit 0