From cd3f577c8520035ab4b51dd62d3b033a253a3911 Mon Sep 17 00:00:00 2001
From: Nicholas Marriott <nicholas.marriott@gmail.com>
Date: Mon, 3 Aug 2026 20:27:10 +0100
Subject: [PATCH] Add test for control mode events and guards.

---
 regress/control-notify-guard.sh | 158 ++++++++++++++++++++++++++++++++
 1 file changed, 158 insertions(+)
 create mode 100755 regress/control-notify-guard.sh

diff --git a/regress/control-notify-guard.sh b/regress/control-notify-guard.sh
new file mode 100755
index 000000000..459ec9f35
--- /dev/null
+++ b/regress/control-notify-guard.sh
@@ -0,0 +1,158 @@
+#!/bin/sh
+
+PATH=/bin:/usr/bin
+TERM=screen
+LC_ALL=C.UTF-8
+LANG=C.UTF-8
+export TERM LC_ALL LANG
+
+[ -z "$TEST_TMUX" ] && TEST_TMUX=$(readlink -f ../tmux)
+TMUX="$TEST_TMUX -LtestA$$ -f/dev/null"
+
+TMPDIR=$(mktemp -d)
+IN="$TMPDIR/in"
+OUT="$TMPDIR/out"
+BADCFG="$TMPDIR/bad.conf"
+PID=
+
+cleanup()
+{
+	exec 3>&- 2>/dev/null
+	[ -n "$PID" ] && kill "$PID" 2>/dev/null
+	$TMUX kill-server 2>/dev/null
+	rm -rf "$TMPDIR"
+}
+trap cleanup EXIT
+
+fail()
+{
+	echo "$1" >&2
+	[ -s "$OUT" ] && cat "$OUT" >&2
+	exit 1
+}
+
+wait_for()
+{
+	pattern=$1
+	timeout=${2:-60}
+	i=0
+
+	while [ "$i" -lt "$timeout" ]; do
+		grep -F -- "$pattern" "$OUT" >/dev/null 2>&1 && return 0
+		sleep 0.1
+		i=$((i + 1))
+	done
+	fail "missing: $pattern"
+}
+
+wait_for_count()
+{
+	pattern=$1
+	expected=$2
+	timeout=${3:-60}
+	i=0
+
+	while [ "$i" -lt "$timeout" ]; do
+		count=$(grep -F -c -- "$pattern" "$OUT" 2>/dev/null)
+		[ "$count" -ge "$expected" ] && return 0
+		sleep 0.1
+		i=$((i + 1))
+	done
+	fail "missing count $expected for: $pattern"
+}
+
+send()
+{
+	printf '%s\n' "$1" >&3 || fail "failed to send: $1"
+}
+
+# A notification is a standalone protocol message. It must never be part of
+# the response between the real %begin and matching %end or %error for a
+# command. Ignore guard-looking command output while a real guard is open.
+check_guards()
+{
+	awk '
+	function notification(line) {
+		return line ~ /^%(sessions-changed|session-changed |unlinked-window-add )/ ||
+		    line ~ /^%(pause |continue |config-error )/
+	}
+	!open && $0 ~ /^%begin [0-9]+ [0-9]+ [0-9]+$/ {
+		open = 1
+		time = $2
+		number = $3
+		flags = $4
+		next
+	}
+	open && ($0 == "%end " time " " number " " flags ||
+	    $0 == "%error " time " " number " " flags) {
+		open = 0
+		next
+	}
+	notification($0) {
+		seen[$1]++
+		if (open) {
+			print "notification inside guard: " $0 > "/dev/stderr"
+			bad = 1
+		}
+	}
+	END {
+		if (open) {
+			print "unterminated command guard" > "/dev/stderr"
+			bad = 1
+		}
+		if (seen["%sessions-changed"] < 2 ||
+		    seen["%session-changed"] < 1 ||
+		    seen["%unlinked-window-add"] < 2 ||
+		    seen["%pause"] < 1 || seen["%continue"] < 1 ||
+		    seen["%config-error"] < 1) {
+			print "missing expected notification" > "/dev/stderr"
+			bad = 1
+		}
+		exit bad
+	}' "$OUT" || fail "bad control protocol notification ordering"
+}
+
+$TMUX kill-server 2>/dev/null
+$TMUX new-session -d -s guard -x 80 -y 24 || exit 1
+pane=$($TMUX display-message -p -t guard:0.0 '#{pane_id}') || exit 1
+
+mkfifo "$IN" || exit 1
+: >"$OUT"
+$TMUX -C attach-session -t guard <"$IN" >"$OUT" 2>&1 &
+PID=$!
+exec 3>"$IN"
+
+# Attaching generates a session notification synchronously from inside the
+# attach command. It must follow the closing guard.
+wait_for '%session-changed '
+
+# Guard-looking output is arbitrary command output, not protocol state. Make
+# new-session both generate notifications and print an unmatched fake %begin;
+# it must not leave those notifications permanently deferred.
+send "set-option -g @fake-begin '%begin 1 2 3'"
+send "new-session -d -P -F '#{@fake-begin}' -s fake-begin"
+wait_for_count '%sessions-changed' 1
+
+# Likewise, fake %end output from a command that generates multiple
+# notifications must not flush them before the command actually ends.
+send "set-option -g @fake-end '%end 1 2 3'"
+send "new-session -d -P -F '#{@fake-end}' -s fake-end"
+wait_for_count '%sessions-changed' 2
+
+# Exercise notification paths outside control-notify.c.
+send "refresh-client -A '$pane:pause'"
+wait_for "%pause $pane"
+send "refresh-client -A '$pane:continue'"
+wait_for "%continue $pane"
+
+printf '%s\n' 'not-a-command' >"$BADCFG"
+send "source-file '$BADCFG'"
+wait_for '%config-error '
+
+# A final command guarantees all earlier command guards have completed before
+# the transcript is checked.
+send "display-message -p 'guard-check-done'"
+wait_for 'guard-check-done'
+check_guards
+
+exit 0