From 12fb1c1e24d59eba470e1a38a2c124044025b0a9 Mon Sep 17 00:00:00 2001
From: Hayato Kuroda <kuroda.hayato@fujitsu.com>
Date: Wed, 7 Oct 2026 15:46:50 +0900
Subject: [PATCH v2 3/4] Reproduce the mixture of the error context by REPACK
 CONCURRENTLY

---
 src/backend/commands/repack_worker.c          |  3 +
 src/test/modules/injection_points/Makefile    |  2 +
 src/test/modules/injection_points/meson.build |  8 ++
 .../t/001_repack_error_context.pl             | 76 +++++++++++++++++++
 4 files changed, 89 insertions(+)
 create mode 100644 src/test/modules/injection_points/t/001_repack_error_context.pl

diff --git a/src/backend/commands/repack_worker.c b/src/backend/commands/repack_worker.c
index d355b9954fc..7dd6c288504 100644
--- a/src/backend/commands/repack_worker.c
+++ b/src/backend/commands/repack_worker.c
@@ -28,6 +28,7 @@
 #include "storage/proc.h"
 #include "tcop/tcopprot.h"
 #include "utils/guc.h"
+#include "utils/injection_point.h"
 #include "utils/memutils.h"
 
 #define PGREPACK_PLUGIN   "pgrepack"
@@ -396,6 +397,8 @@ decode_concurrent_changes(LogicalDecodingContext *ctx,
 		char	   *errm = NULL;
 		XLogRecPtr	end_lsn;
 
+		INJECTION_POINT("repack-worker-error-context", NULL);
+
 		CHECK_FOR_INTERRUPTS();
 
 		record = XLogReadRecord(ctx->reader, &errm);
diff --git a/src/test/modules/injection_points/Makefile b/src/test/modules/injection_points/Makefile
index 2463d6e0fb9..1ca1dc98d02 100644
--- a/src/test/modules/injection_points/Makefile
+++ b/src/test/modules/injection_points/Makefile
@@ -45,6 +45,8 @@ NO_INSTALLCHECK = 1
 
 export enable_injection_points
 
+TAP_TESTS = 1
+
 ifdef USE_PGXS
 PG_CONFIG = pg_config
 PGXS := $(shell $(PG_CONFIG) --pgxs)
diff --git a/src/test/modules/injection_points/meson.build b/src/test/modules/injection_points/meson.build
index b4a0079484b..8695d45b1b0 100644
--- a/src/test/modules/injection_points/meson.build
+++ b/src/test/modules/injection_points/meson.build
@@ -77,4 +77,12 @@ tests += {
       '--temp-config', files('extra.conf'),
     ],
   },
+  'tap': {
+    'env': {
+      'enable_injection_points': 'yes',
+    },
+    'tests': [
+      't/001_repack_error_context.pl',
+    ],
+  },
 }
diff --git a/src/test/modules/injection_points/t/001_repack_error_context.pl b/src/test/modules/injection_points/t/001_repack_error_context.pl
new file mode 100644
index 00000000000..9c348e1bfb6
--- /dev/null
+++ b/src/test/modules/injection_points/t/001_repack_error_context.pl
@@ -0,0 +1,76 @@
+# Copyright (c) 2026, PostgreSQL Global Development Group
+
+# Test that an error propagated by the REPACK decoding worker does not use
+# a current context on the backend.
+use strict;
+use warnings FATAL => 'all';
+use PostgreSQL::Test::Cluster;
+use PostgreSQL::Test::Utils;
+use Test::More;
+
+my $node = PostgreSQL::Test::Cluster->new('repack_error_context');
+# wal_level must be higher than 'replica'
+$node->init(allows_streaming => 1);
+$node->start;
+
+if (!$node->check_extension('injection_points'))
+{
+	plan skip_all => 'Extension injection_points not installed';
+}
+
+# Setup a node
+$node->safe_psql('postgres',
+	"CREATE EXTENSION injection_points WITH SCHEMA public;");
+$node->safe_psql('postgres',
+	"CREATE TABLE repack_error_context_test (i integer PRIMARY KEY);");
+$node->safe_psql('postgres',
+	"INSERT INTO repack_error_context_test SELECT generate_series(1, 100);");
+
+# Define a function that triggers an injection point. The backend would wait at
+# this point by the upcoming test.
+$node->safe_psql('postgres', qq[
+	CREATE FUNCTION repack_error_context(integer) RETURNS integer
+	LANGUAGE plpgsql IMMUTABLE AS \$\$
+	BEGIN
+		PERFORM public.injection_points_run('repack-leader-error-context');
+		RETURN \$1;
+	END;
+	\$\$;
+]);
+
+# Define an index which uses the repack_error_context function
+$node->safe_psql('postgres',
+	"CREATE INDEX repack_error_context_idx ON repack_error_context_test (repack_error_context(i));");
+
+$node->safe_psql('postgres',
+	"SELECT injection_points_attach('repack-leader-error-context', 'wait');");
+
+my $log_offset = -s $node->logfile;
+
+# Run REPACK CONCURRENTLY. The command would wait at the injection point.
+my $session = $node->background_psql('postgres', on_error_stop => 0);
+$session->query_until(
+	qr/repack_started/,
+	q[
+\echo repack_started
+REPACK (CONCURRENTLY) repack_error_context_test;
+]);
+$node->wait_for_event('client backend', 'repack-leader-error-context');
+
+# Attach another injection point for the repack worker to raise an error
+$node->safe_psql('postgres',
+	"SELECT injection_points_attach('repack-worker-error-context', 'error')");
+
+$node->wait_for_log(
+	qr/client backend.*ERROR:  error triggered for injection point repack-worker-error-context/,
+	$log_offset);
+
+$session->quit;
+
+my $log_contents = slurp_file($node->logfile, $log_offset);
+unlike(
+	$log_contents,
+	qr/PL\/pgSQL function public\.repack_error_context/,
+	'worker error does not use the backend PL/pgSQL context');
+
+done_testing();
-- 
2.52.0