upstream: Add test for client termination status on signal.

Based on patch from Alexxz via github PR#235 with some tweaks, to
match patch in bz#3281.

OpenBSD-Regress-ID: d87c7446fb8b5f8b45894fbbd6875df326e729e2

regress/Makefile

@@ -1,4 +1,4 @@
-#	$OpenBSD: Makefile,v 1.116 2021/08/04 21:28:00 djm Exp $
+#	$OpenBSD: Makefile,v 1.117 2021/09/03 04:11:13 dtucker Exp $
 
 tests:		prep file-tests t-exec unit
 
@@ -27,6 +27,7 @@ LTESTS= 	connect \
 		proto-version \
 		proto-mismatch \
 		exit-status \
+		exit-status-signal \
 		envpass \
 		transfer \
 		banner \

regress/exit-status-signal.sh

@@ -0,0 +1,24 @@
+# This test performs validation that ssh client is not successive on being terminated
+
+tid="exit status on signal"
+
+# spawn client in background
+rm -f $OBJ/remote_pid
+${SSH} -F $OBJ/ssh_proxy somehost 'echo $$ >'$OBJ'/remote_pid; sleep 444' &
+ssh_pid=$!
+
+# wait for it to start
+n=20
+while [ ! -f $OBJ/remote_pid ] && [ $n -gt 0 ]; do
+	n=$(($n - 1))
+	sleep 1
+done
+
+kill $ssh_pid
+wait $ssh_pid
+exit_code=$?
+
+if [ $exit_code -eq 0 ]; then
+	fail "ssh client should fail on signal"
+fi
+