tests: add regression test for `systemctl restart systemd-journald`

See https://github.com/systemd/systemd/issues/2236

test/TEST-04-JOURNAL/test-journal.sh

@@ -51,5 +51,13 @@ journalctl --sync
 journalctl -b -o cat -t "$ID" >/output
 cmp /expected /output
 
+# Don't lose streams on restart
+systemctl start forever-print-hola
+sleep 3
+systemctl restart systemd-journald
+sleep 3
+systemctl stop forever-print-hola
+[[ ! -f "/i-lose-my-logs" ]]
+
 touch /testok
 exit 0

test/TEST-04-JOURNAL/test.sh

@@ -55,6 +55,15 @@ After=multi-user.target
 [Service]
 ExecStart=/test-journal.sh
 Type=oneshot
+EOF
+
+        cat >$initdir/etc/systemd/system/forever-print-hola.service <<EOF
+[Unit]
+Description=ForeverPrintHola service
+
+[Service]
+Type=simple
+ExecStart=/bin/sh -x -c 'while :; do printf "Hola\n" || touch /i-lose-my-logs; sleep 1; done'
 EOF
 
         cp test-journal.sh $initdir/