From 4c65f8e58b0f0eae4a9ea6aba8838273c1bc8c62 Mon Sep 17 00:00:00 2001
From: Michael Paquier <michael@paquier.xyz>
Date: Tue, 9 Jan 2024 13:30:56 +0900
Subject: [PATCH v9 3/4] Add regression test to show snapbuild consistency

Reverting 409f9ca44713 causes the test to fail.  The test added here
relies on the existing callbacks in injection_points.
---
 src/backend/replication/logical/snapbuild.c |  3 ++
 src/test/recovery/Makefile                  |  7 ++-
 src/test/recovery/meson.build               |  4 ++
 src/test/recovery/t/040_snapshot_status.pl  | 51 +++++++++++++++++++++
 4 files changed, 64 insertions(+), 1 deletion(-)
 create mode 100644 src/test/recovery/t/040_snapshot_status.pl

diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c
index a0b7947d2f..93048afc2f 100644
--- a/src/backend/replication/logical/snapbuild.c
+++ b/src/backend/replication/logical/snapbuild.c
@@ -141,6 +141,7 @@
 #include "storage/procarray.h"
 #include "storage/standby.h"
 #include "utils/builtins.h"
+#include "utils/injection_point.h"
 #include "utils/memutils.h"
 #include "utils/snapmgr.h"
 #include "utils/snapshot.h"
@@ -654,6 +655,8 @@ SnapBuildInitialSnapshot(SnapBuild *builder)
 	snap->xcnt = newxcnt;
 	snap->xip = newxip;
 
+	INJECTION_POINT("SnapBuildInitialSnapshot");
+
 	return snap;
 }
 
diff --git a/src/test/recovery/Makefile b/src/test/recovery/Makefile
index 17ee353735..f57baba5e8 100644
--- a/src/test/recovery/Makefile
+++ b/src/test/recovery/Makefile
@@ -9,12 +9,17 @@
 #
 #-------------------------------------------------------------------------
 
-EXTRA_INSTALL=contrib/pg_prewarm contrib/pg_stat_statements contrib/test_decoding
+EXTRA_INSTALL=contrib/pg_prewarm \
+	contrib/pg_stat_statements \
+	contrib/test_decoding \
+	src/test/modules/injection_points
 
 subdir = src/test/recovery
 top_builddir = ../../..
 include $(top_builddir)/src/Makefile.global
 
+export enable_injection_points enable_injection_points
+
 # required for 017_shm.pl and 027_stream_regress.pl
 REGRESS_SHLIB=$(abs_top_builddir)/src/test/regress/regress$(DLSUFFIX)
 export REGRESS_SHLIB
diff --git a/src/test/recovery/meson.build b/src/test/recovery/meson.build
index 88fb0306f5..43d7411a79 100644
--- a/src/test/recovery/meson.build
+++ b/src/test/recovery/meson.build
@@ -6,6 +6,9 @@ tests += {
   'bd': meson.current_build_dir(),
   'tap': {
     'test_kwargs': {'priority': 40}, # recovery tests are slow, start early
+    'env': {
+      'enable_injection_points': get_option('injection_points') ? 'yes' : 'no',
+    },
     'tests': [
       't/001_stream_rep.pl',
       't/002_archiving.pl',
@@ -45,6 +48,7 @@ tests += {
       't/037_invalid_database.pl',
       't/038_save_logical_slots_shutdown.pl',
       't/039_end_of_wal.pl',
+      't/040_snapshot_status.pl',
     ],
   },
 }
diff --git a/src/test/recovery/t/040_snapshot_status.pl b/src/test/recovery/t/040_snapshot_status.pl
new file mode 100644
index 0000000000..e77b138144
--- /dev/null
+++ b/src/test/recovery/t/040_snapshot_status.pl
@@ -0,0 +1,51 @@
+# Test consistent of initial snapshot data.
+
+# This requires a node with wal_level=logical combined with an injection
+# point that forces a failure when a snapshot is initially built with a
+# logical slot created.
+#
+# See bug https://postgr.es/m/CAFiTN-s0zA1Kj0ozGHwkYkHwa5U0zUE94RSc_g81WrpcETB5=w@mail.gmail.com.
+
+use strict;
+use warnings;
+
+use PostgreSQL::Test::Cluster;
+use PostgreSQL::Test::Utils;
+use Test::More;
+
+if ($ENV{enable_injection_points} ne 'yes')
+{
+	plan skip_all => 'Injection points not supported by this build';
+}
+
+my $node = PostgreSQL::Test::Cluster->new('node');
+$node->init(allows_streaming => 'logical');
+$node->start;
+
+$node->safe_psql('postgres', 'CREATE EXTENSION injection_points;');
+$node->safe_psql('postgres',
+  "SELECT injection_points_attach('SnapBuildInitialSnapshot', 'error');");
+
+my $node_host = $node->host;
+my $node_port = $node->port;
+my $connstr_common = "host=$node_host port=$node_port";
+my $connstr_db = "$connstr_common replication=database dbname=postgres";
+
+# This requires a single session, with two commands.
+my $psql_session =
+  $node->background_psql('postgres', on_error_stop => 0,
+			 extra_params => [ '-d', $connstr_db ]);
+my ($output, $ret) = $psql_session->query(
+    'CREATE_REPLICATION_SLOT "slot" LOGICAL "pgoutput";');
+ok($ret != 0, "First CREATE_REPLICATION_SLOT fails on injected error");
+
+# Now remove the injected error and check that the second command works.
+$node->safe_psql('postgres',
+  "SELECT injection_points_detach('SnapBuildInitialSnapshot');");
+
+($output, $ret) = $psql_session->query(
+    'CREATE_REPLICATION_SLOT "slot" LOGICAL "pgoutput";');
+ok(substr($output, 0, 4) eq 'slot',
+   "Second CREATE_REPLICATION_SLOT passes");
+
+done_testing();
-- 
2.43.0