From 92537befabccbbd8e5e16f14f7cf3f25b4562399 Mon Sep 17 00:00:00 2001
From: Zhijie Hou <houzj.fnst@fujitsu.com>
Date: Wed, 27 May 2026 15:58:05 +0800
Subject: [PATCH v5] Add TAP test for WAL recycling during REPACK CONCURRENTLY

Following 45b0298 which allows old WAL recycling during REPACK CONCURRENTLY,
this commit adds a TAP test to verify the intended behavior and helps prevent
future regressions in WAL retention during long-running REPACK CONCURRENTLY
operations.
---
 .../recovery/t/046_checkpoint_logical_slot.pl | 83 +++++++++++++++++++
 1 file changed, 83 insertions(+)

diff --git a/src/test/recovery/t/046_checkpoint_logical_slot.pl b/src/test/recovery/t/046_checkpoint_logical_slot.pl
index 66761bf56c1..778bdf42406 100644
--- a/src/test/recovery/t/046_checkpoint_logical_slot.pl
+++ b/src/test/recovery/t/046_checkpoint_logical_slot.pl
@@ -226,4 +226,87 @@ is( $standby->safe_psql(
 	"t",
 	'logical slot is not invalidated');
 
+# Clean up old replication slots that might interfere with later WAL removal
+# tests.
+$standby->stop;
+$primary->safe_psql('postgres',
+	q{SELECT pg_drop_replication_slot('slot_logical');
+	SELECT pg_drop_replication_slot('slot_physical');
+	SELECT pg_drop_replication_slot('failover_slot');
+	SELECT pg_drop_replication_slot('phys_slot');});
+
+# Verify that the REPACK slot's restart_lsn can advance while REPACK
+# CONCURRENTLY is still running, allowing WAL files to be recycled during this
+# period.
+
+# Create the table to be repacked and populate it with some data.
+$node->safe_psql(
+	'postgres',
+	q{
+CREATE TABLE repack_test(i int PRIMARY KEY, t text);
+INSERT INTO repack_test
+SELECT g, md5(g::text)
+FROM generate_series(1, 100) g;
+});
+
+# Pause the REPACK command in the middle of its execution so that the decoding
+# worker continues running, allowing us to test slot restart_lsn advancement
+# later.
+$node->safe_psql('postgres',
+	q(select injection_points_attach('repack-concurrently-before-lock','wait'))
+);
+
+my $repack = $node->background_psql('postgres');
+$repack->query_until(
+	qr/repack_started/,
+	q(
+\echo repack_started
+REPACK (CONCURRENTLY) repack_test;
+\q
+));
+
+# Wait until REPACK reaches the injection point.
+$node->wait_for_event('client backend', 'repack-concurrently-before-lock');
+
+my $restart_lsn_before = $node->safe_psql('postgres',
+	"SELECT restart_lsn FROM pg_replication_slots WHERE slot_name ~ '^repack_[0-9]+' AND slot_type = 'logical' AND temporary;");
+
+# Verify that the replication slot created by the subscription exists and has a
+# valid restart_lsn.
+ok(defined($restart_lsn_before) && $restart_lsn_before ne '',
+	'REPACK slot has restart_lsn');
+
+my $segment_before = $node->safe_psql('postgres',
+	"SELECT pg_walfile_name('$restart_lsn_before')");
+my $segment_before_path = $node->data_dir . "/pg_wal/$segment_before";
+ok(-f $segment_before_path,
+	"segment for initial restart_lsn exists: $segment_before");
+
+# Switch WAL file on the primary while REPACK is still running and then force
+# WAL removal/recycling with a checkpoint.
+$node->advance_wal(1);
+
+# Wait until the REPACK slot's restart_lsn advances
+ok( $node->poll_query_until(
+	'postgres', qq[
+    SELECT count(*) > 0
+	FROM pg_replication_slots
+	WHERE slot_name ~ '^repack_[0-9]+'
+	  AND slot_type = 'logical'
+	  AND temporary
+	  AND restart_lsn IS NOT NULL
+	  AND restart_lsn <> '$restart_lsn_before'::pg_lsn]),
+	'REPACK slot restart_lsn advances while command is still running');
+
+$node->safe_psql('postgres', 'CHECKPOINT');
+
+# Test that the old WAL segment was recycled
+ok(!-f $segment_before_path,
+	'old WAL segment was recycled while REPACK CONCURRENTLY was running');
+
+$node->safe_psql('postgres',
+	"SELECT injection_points_wakeup('repack-concurrently-before-lock')");
+
+$repack->quit;
+
 done_testing();
-- 
2.43.0