From b425bf0081386a544e1faf872a75da69a971e173 Mon Sep 17 00:00:00 2001
From: Andrew Dunstan <andrew@dunslane.net>
Date: Wed, 23 Nov 2022 07:03:06 -0500
Subject: [PATCH] Fix perl warning from commit 9b4eafcaf4

per gripe from Andres Freund and Tom Lane

Backpatch to all live branches.
---
 src/test/perl/PostgreSQL/Test/Cluster.pm | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/test/perl/PostgreSQL/Test/Cluster.pm b/src/test/perl/PostgreSQL/Test/Cluster.pm
index 6101740ca0..7411188dc8 100644
--- a/src/test/perl/PostgreSQL/Test/Cluster.pm
+++ b/src/test/perl/PostgreSQL/Test/Cluster.pm
@@ -1593,7 +1593,7 @@ sub _reserve_port
 	# take an exclusive lock to avoid concurrent access
 	flock($portfile, LOCK_EX) || die "locking port file $filename: $!";
 	# see if someone else has or had a reservation of this port
-	my $pid = <$portfile>;
+	my $pid = <$portfile> || "0";
 	chomp $pid;
 	if ($pid +0 > 0)
 	{