[pull] master from postgres:master

contrib/amcheck/expected/check_gin.out

@@ -76,3 +76,15 @@ SELECT gin_index_check('gin_check_jsonb_idx');
 
 -- cleanup
 DROP TABLE gin_check_jsonb;
+-- Test GIN multicolumn index
+CREATE TABLE "gin_check_multicolumn"(a text[], b text[]);
+INSERT INTO gin_check_multicolumn (a,b) values ('{a,c,e}','{b,d,f}');
+CREATE INDEX "gin_check_multicolumn_idx" on gin_check_multicolumn USING GIN(a,b);
+SELECT gin_index_check('gin_check_multicolumn_idx');
+ gin_index_check 
+-----------------
+
+(1 row)
+
+-- cleanup
+DROP TABLE gin_check_multicolumn;

contrib/amcheck/meson.build

@@ -49,6 +49,7 @@ tests += {
       't/003_cic_2pc.pl',
       't/004_verify_nbtree_unique.pl',
       't/005_pitr.pl',
+      't/006_verify_gin.pl',
     ],
   },
 }

contrib/amcheck/sql/check_gin.sql

@@ -50,3 +50,13 @@ SELECT gin_index_check('gin_check_jsonb_idx');
 
 -- cleanup
 DROP TABLE gin_check_jsonb;
+
+-- Test GIN multicolumn index
+CREATE TABLE "gin_check_multicolumn"(a text[], b text[]);
+INSERT INTO gin_check_multicolumn (a,b) values ('{a,c,e}','{b,d,f}');
+CREATE INDEX "gin_check_multicolumn_idx" on gin_check_multicolumn USING GIN(a,b);
+
+SELECT gin_index_check('gin_check_multicolumn_idx');
+
+-- cleanup
+DROP TABLE gin_check_multicolumn;

contrib/amcheck/t/006_verify_gin.pl

@@ -0,0 +1,199 @@
+
+# Copyright (c) 2021-2025, PostgreSQL Global Development Group
+
+use strict;
+use warnings FATAL => 'all';
+
+use PostgreSQL::Test::Cluster;
+use PostgreSQL::Test::Utils;
+
+use Test::More;
+
+my $node;
+my $blksize;
+
+# to get the split fast, we want tuples to be as large as possible, but the same time we don't want them to be toasted.
+my $filler_size = 1900;
+
+#
+# Test set-up
+#
+$node = PostgreSQL::Test::Cluster->new('test');
+$node->init(no_data_checksums => 1);
+$node->append_conf('postgresql.conf', 'autovacuum=off');
+$node->start;
+$blksize = int($node->safe_psql('postgres', 'SHOW block_size;'));
+$node->safe_psql('postgres', q(CREATE EXTENSION amcheck));
+$node->safe_psql(
+	'postgres', q(
+		CREATE OR REPLACE FUNCTION  random_string( INT ) RETURNS text AS $$
+		SELECT string_agg(substring('0123456789abcdefghijklmnopqrstuvwxyz', ceil(random() * 36)::integer, 1), '') from generate_series(1, $1);
+		$$ LANGUAGE SQL;));
+
+# Tests
+invalid_entry_order_leaf_page_test();
+invalid_entry_order_inner_page_test();
+invalid_entry_columns_order_test();
+
+sub invalid_entry_order_leaf_page_test
+{
+	my $relname = "test";
+	my $indexname = "test_gin_idx";
+
+	$node->safe_psql(
+		'postgres', qq(
+		DROP TABLE IF EXISTS $relname;
+		CREATE TABLE $relname (a text[]);
+		INSERT INTO $relname (a) VALUES ('{aaaaa,bbbbb}');
+		CREATE INDEX $indexname ON $relname USING gin (a);
+	 ));
+	my $relpath = relation_filepath($indexname);
+
+	$node->stop;
+
+	my $blkno = 1;  # root
+
+	# produce wrong order by replacing aaaaa with ccccc
+	string_replace_block(
+		$relpath,
+		'aaaaa',
+		'ccccc',
+		$blkno
+	);
+
+	$node->start;
+
+	my ($result, $stdout, $stderr) = $node->psql('postgres', qq(SELECT gin_index_check('$indexname')));
+	my $expected = "index \"$indexname\" has wrong tuple order on entry tree page, block 1, offset 2, rightlink 4294967295";
+	like($stderr, qr/$expected/);
+}
+
+sub invalid_entry_order_inner_page_test
+{
+	my $relname = "test";
+	my $indexname = "test_gin_idx";
+
+	# to break the order in the inner page we need at least 3 items (rightmost key in the inner level is not checked for the order)
+	# so fill table until we have 2 splits
+	$node->safe_psql(
+		'postgres', qq(
+		DROP TABLE IF EXISTS $relname;
+		CREATE TABLE $relname (a text[]);
+		INSERT INTO $relname (a) VALUES (('{' || 'pppppppppp' || random_string($filler_size) ||'}')::text[]);
+		INSERT INTO $relname (a) VALUES (('{' || 'qqqqqqqqqq' || random_string($filler_size) ||'}')::text[]);
+		INSERT INTO $relname (a) VALUES (('{' || 'rrrrrrrrrr' || random_string($filler_size) ||'}')::text[]);
+		INSERT INTO $relname (a) VALUES (('{' || 'ssssssssss' || random_string($filler_size) ||'}')::text[]);
+		INSERT INTO $relname (a) VALUES (('{' || 'tttttttttt' || random_string($filler_size) ||'}')::text[]);
+		INSERT INTO $relname (a) VALUES (('{' || 'uuuuuuuuuu' || random_string($filler_size) ||'}')::text[]);
+		INSERT INTO $relname (a) VALUES (('{' || 'vvvvvvvvvv' || random_string($filler_size) ||'}')::text[]);
+		INSERT INTO $relname (a) VALUES (('{' || 'wwwwwwwwww' || random_string($filler_size) ||'}')::text[]);
+		CREATE INDEX $indexname ON $relname USING gin (a);
+	));
+	my $relpath = relation_filepath($indexname);
+
+	$node->stop;
+
+	my $blkno = 1;  # root
+
+	# we have rrrrrrrrr... and tttttttttt... as keys in the root, so produce wrong order by replacing rrrrrrrrrr....
+	string_replace_block(
+		$relpath,
+		'rrrrrrrrrr',
+		'zzzzzzzzzz',
+		$blkno
+	);
+
+	$node->start;
+
+	my ($result, $stdout, $stderr) = $node->psql('postgres', qq(SELECT gin_index_check('$indexname')));
+	my $expected = "index \"$indexname\" has wrong tuple order on entry tree page, block 1, offset 2, rightlink 4294967295";
+	like($stderr, qr/$expected/);
+}
+
+sub invalid_entry_columns_order_test
+{
+	my $relname = "test";
+	my $indexname = "test_gin_idx";
+
+	$node->safe_psql(
+		'postgres', qq(
+		DROP TABLE IF EXISTS $relname;
+		CREATE TABLE $relname (a text[],b text[]);
+		INSERT INTO $relname (a,b) VALUES ('{aaa}','{bbb}');
+		CREATE INDEX $indexname ON $relname USING gin (a,b);
+	));
+	my $relpath = relation_filepath($indexname);
+
+	$node->stop;
+
+	my $blkno = 1;  # root
+
+	# mess column numbers
+	# root items order before: (1,aaa), (2,bbb)
+	# root items order after:  (2,aaa), (1,bbb)
+	my $attrno_1 = pack('s', 1);
+	my $attrno_2 = pack('s', 2);
+
+	my $find = qr/($attrno_1)(.)(aaa)/s;
+	my $replace = $attrno_2 . '$2$3';
+	string_replace_block(
+		$relpath,
+		$find,
+		$replace,
+		$blkno
+	);
+
+	$find = qr/($attrno_2)(.)(bbb)/s;
+	$replace = $attrno_1 . '$2$3';
+	string_replace_block(
+		$relpath,
+		$find,
+		$replace,
+		$blkno
+	);
+
+	$node->start;
+
+	my ($result, $stdout, $stderr) = $node->psql('postgres', qq(SELECT gin_index_check('$indexname')));
+	my $expected = "index \"$indexname\" has wrong tuple order on entry tree page, block 1, offset 2, rightlink 4294967295";
+	like($stderr, qr/$expected/);
+}
+
+# Returns the filesystem path for the named relation.
+sub relation_filepath
+{
+	my ($relname) = @_;
+
+	my $pgdata = $node->data_dir;
+	my $rel = $node->safe_psql('postgres',
+		qq(SELECT pg_relation_filepath('$relname')));
+	die "path not found for relation $relname" unless defined $rel;
+	return "$pgdata/$rel";
+}
+
+# substitute pattern 'find' with 'replace' within the block with number 'blkno' in the file 'filename'
+sub string_replace_block
+{
+	my ($filename, $find, $replace, $blkno) = @_;
+
+	my $fh;
+	open($fh, '+<', $filename) or BAIL_OUT("open failed: $!");
+	binmode $fh;
+
+	my $offset = $blkno * $blksize;
+	my $buffer;
+
+	sysseek($fh, $offset, 0) or BAIL_OUT("seek failed: $!");
+	sysread($fh, $buffer, $blksize) or BAIL_OUT("read failed: $!");
+
+	$buffer =~ s/$find/'"' . $replace . '"'/gee;
+
+	sysseek($fh, $offset, 0) or BAIL_OUT("seek failed: $!");
+	syswrite($fh, $buffer) or BAIL_OUT("write failed: $!");
+
+	close($fh) or BAIL_OUT("close failed: $!");
+
+	return;
+}
+
+done_testing();