From 38c67b0fd8f2d83e97a93108484fe23c881dd91c Mon Sep 17 00:00:00 2001
From: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Date: Mon, 8 May 2023 07:02:50 +0000
Subject: [PATCH v1] fix retaining WAL test

---
 .../t/035_standby_logical_decoding.pl         | 38 ++++++++++---------
 1 file changed, 21 insertions(+), 17 deletions(-)
 100.0% src/test/recovery/t/

diff --git a/src/test/recovery/t/035_standby_logical_decoding.pl b/src/test/recovery/t/035_standby_logical_decoding.pl
index ad1def2474..4bda706eae 100644
--- a/src/test/recovery/t/035_standby_logical_decoding.pl
+++ b/src/test/recovery/t/035_standby_logical_decoding.pl
@@ -276,20 +276,6 @@ $node_standby->append_conf('postgresql.conf',
        max_replication_slots = 5]);
 $node_standby->start;
 $node_primary->wait_for_replay_catchup($node_standby);
-$node_standby->safe_psql('testdb', qq[SELECT * FROM pg_create_physical_replication_slot('$standby_physical_slotname');]);
-
-#######################
-# Initialize cascading standby node
-#######################
-$node_standby->backup($backup_name);
-$node_cascading_standby->init_from_backup(
-	$node_standby, $backup_name,
-	has_streaming => 1,
-	has_restoring => 1);
-$node_cascading_standby->append_conf('postgresql.conf',
-	qq[primary_slot_name = '$standby_physical_slotname']);
-$node_cascading_standby->start;
-$node_standby->wait_for_replay_catchup($node_cascading_standby, $node_primary);
 
 #######################
 # Initialize subscriber node
@@ -503,9 +489,6 @@ check_slots_conflicting_status(1);
 # Verify that invalidated logical slots do not lead to retaining WAL.
 ##################################################
 
-# Wait for the cascading standby to catchup before removing the WAL file(s)
-$node_standby->wait_for_replay_catchup($node_cascading_standby, $node_primary);
-
 # Get the restart_lsn from an invalidated slot
 my $restart_lsn = $node_standby->safe_psql('postgres',
 	"SELECT restart_lsn from pg_replication_slots WHERE slot_name = 'vacuum_full_activeslot' and conflicting is true;"
@@ -538,6 +521,27 @@ my $standby_walfile = $node_standby->data_dir . '/pg_wal/' . $walfile_name;
 ok(!-f "$standby_walfile",
 	"invalidated logical slots do not lead to retaining WAL");
 
+# Now create the physical slot on the standby and initialize the cascading standby node.
+# It's done here because the physical slot on the standby could prevent the WAL
+# file to be removed in the test above (ensuring the WAL file removal could still be
+# possible but we want to keep the above test simple).
+# Also please note that the cascading standby will be created with hot_standby_feedback
+# set to on thanks to the last change_hot_standby_feedback_and_wait_for_xmins() call.
+$node_standby->safe_psql('testdb', qq[SELECT * FROM pg_create_physical_replication_slot('$standby_physical_slotname');]);
+
+#######################
+# Initialize cascading standby node
+#######################
+$node_standby->backup($backup_name);
+$node_cascading_standby->init_from_backup(
+	$node_standby, $backup_name,
+	has_streaming => 1,
+	has_restoring => 1);
+$node_cascading_standby->append_conf('postgresql.conf',
+	qq[primary_slot_name = '$standby_physical_slotname']);
+$node_cascading_standby->start;
+$node_standby->wait_for_replay_catchup($node_cascading_standby, $node_primary);
+
 ##################################################
 # Recovery conflict: Invalidate conflicting slots, including in-use slots
 # Scenario 2: conflict due to row removal with hot_standby_feedback off.
-- 
2.34.1