From: Alvaro Herrera <alvherre@alvh.no-ip.org>
Date: Thu, 10 Jun 2021 16:44:03 -0400
Subject: [PATCH 2/2] the test

---
 src/test/recovery/t/019_replslot_limit.pl | 73 ++++++++++++++++++++++-
 1 file changed, 70 insertions(+), 3 deletions(-)

diff --git a/src/test/recovery/t/019_replslot_limit.pl b/src/test/recovery/t/019_replslot_limit.pl
index 7094aa0704..fa47c915a5 100644
--- a/src/test/recovery/t/019_replslot_limit.pl
+++ b/src/test/recovery/t/019_replslot_limit.pl
@@ -11,7 +11,7 @@ use TestLib;
 use PostgresNode;
 
 use File::Path qw(rmtree);
-use Test::More tests => 14;
+use Test::More tests => 17;
 use Time::HiRes qw(usleep);
 
 $ENV{PGDATABASE} = 'postgres';
@@ -211,8 +211,8 @@ for (my $i = 0; $i < 10000; $i++)
 }
 ok($failed, 'check that replication has been broken');
 
-$node_primary->stop('immediate');
-$node_standby->stop('immediate');
+$node_primary->stop;
+$node_standby->stop;
 
 my $node_primary2 = get_new_node('primary2');
 $node_primary2->init(allows_streaming => 1);
@@ -253,6 +253,73 @@ my @result =
 		timeout => '60'));
 is($result[1], 'finished', 'check if checkpoint command is not blocked');
 
+$node_primary2->stop;
+$node_standby->stop;
+
+# The next test depends on Perl's `kill`, which apparently is not
+# portable to Windows.  (It would be nice to use Test::More's `subtest`,
+# but that's not in the ancient version we require.)
+done_testing() if $TestLib::windows_os;
+
+# Get a slot terminated while the walsender is active
+# We do this by sending SIGSTOP to the walreceiver.  Skip this on Windows.
+my $node_primary3 = get_new_node('primary3');
+$node_primary3->init(allows_streaming => 1, extra => ['--wal-segsize=1']);
+$node_primary3->append_conf(
+	'postgresql.conf', qq(
+	min_wal_size = 2MB
+	max_wal_size = 2MB
+	log_checkpoints = yes
+	max_slot_wal_keep_size = 1MB
+	));
+$node_primary3->start;
+$node_primary3->safe_psql('postgres',
+	"SELECT pg_create_physical_replication_slot('rep3')");
+# Take backup
+$backup_name = 'my_backup';
+$node_primary3->backup($backup_name);
+# Create standby
+my $node_standby3 = get_new_node('standby_3');
+$node_standby3->init_from_backup($node_primary3, $backup_name,
+	has_streaming => 1);
+$node_standby3->append_conf('postgresql.conf', "primary_slot_name = 'rep3'");
+$node_standby3->start;
+$node_primary3->wait_for_catchup($node_standby3->name, 'replay');
+my $pid = $node_standby3->safe_psql('postgres',
+	"SELECT pid FROM pg_stat_activity WHERE backend_type = 'walreceiver'");
+like($pid, qr/^[0-9]+$/, "have walreceiver pid $pid");
+
+# freeze walreceiver. Slot will still be active, but it won't advance
+kill 'STOP', $pid;
+$logstart = get_log_size($node_primary3);
+advance_wal($node_primary3, 2);
+
+my ($in, $out, $timer, $h);
+$timer = IPC::Run::timeout(180);
+$h = $node_primary3->background_psql('postgres', \$in, \$out, $timer);
+$in .= qq{
+checkpoint;
+};
+$h->pump_nb;
+ok( find_in_log($node_primary3,
+		"to release replication slot"),
+	"walreceiver termination logged");
+
+# Now let it continue to its demise
+kill 'CONT', $pid;
+
+$node_primary3->poll_query_until('postgres',
+	"SELECT wal_status FROM pg_replication_slots WHERE slot_name = 'rep3'",
+	"lost") or die "timed out waiting for slot to be lost";
+
+ok( find_in_log($node_primary3,
+		'invalidating slot "rep3" because its restart_lsn'),
+	"slot invalidation logged");
+
+
+$node_primary3->stop;
+$node_standby3->stop;
+
 #####################################
 # Advance WAL of $node by $n segments
 sub advance_wal
-- 
2.20.1


--6s6fi4xhi7ezemxn--