duplicate_archive_test.patch

diff --git a/src/test/recovery/t/020_archive_status.pl b/src/test/recovery/t/020_archive_status.pl
index 777bf05274..ed5e80327b 100644
--- a/src/test/recovery/t/020_archive_status.pl
+++ b/src/test/recovery/t/020_archive_status.pl
@@ -8,7 +8,7 @@ use strict;
 use warnings;
 use PostgresNode;
 use TestLib;
-use Test::More tests => 16;
+use Test::More tests => 17;
 use Config;
 
 my $primary = get_new_node('primary');
@@ -176,6 +176,7 @@ ok( -f "$standby1_data/$segment_path_2_done",
 # will cause archiving failures.
 my $standby2 = get_new_node('standby2');
 $standby2->init_from_backup($primary, 'backup', has_restoring => 1);
+$standby2->enable_archiving;
 $standby2->append_conf('postgresql.conf', 'archive_mode = always');
 my $standby2_data = $standby2->data_dir;
 $standby2->start;
@@ -234,3 +235,49 @@ ok( -f "$standby2_data/$segment_path_1_done"
 	  && -f "$standby2_data/$segment_path_2_done",
 	".done files created after archive success with archive_mode=always on standby"
 );
+
+
+# Check if restart of a archive-replicated standby doesn't archive the
+# same file twice.
+
+# Use duplicate-resistent archive_command
+my $archpath = TestLib::perl2host($standby2->archive_dir);
+$archpath =~ s{\\}{\\\\}g if ($TestLib::windows_os);
+my $nodup_command =
+	  $TestLib::windows_os
+	  ? qq{if not exist "$archpath\\\\%f" (copy "%p" "$archpath\\\\%f") else (exit 1)}
+	  : qq{test ! -f "$archpath/%f" && cp "%p" "$archpath/%f"};
+$standby2->safe_psql(
+	'postgres', qq{
+	ALTER SYSTEM SET archive_command TO '$nodup_command';
+	SELECT pg_reload_conf();
+});
+
+# Remember the current semgent file, The +1 below is an adjustment to avoid
+# segment borders.
+my $cursegfile = $primary->safe_psql(
+	'postgres',
+	'SELECT pg_walfile_name(pg_current_wal_lsn() + 1)');
+$primary->psql('postgres', 'CHECKPOINT; SELECT pg_switch_wal();');
+$standby2->psql('postgres', 'CHECKPOINT');
+$standby2->poll_query_until(
+	'postgres',
+	"SELECT last_archived_wal = '$cursegfile' FROM pg_stat_archiver")
+  or die "Timed out waiting for the segment to be archived";
+
+$standby2->restart;
+
+$primary->psql('postgres', 'CHECKPOINT; SELECT pg_switch_wal();');
+
+$standby2->poll_query_until(
+	'postgres', qq[
+	SELECT last_archived_wal IS NOT NULL OR
+           last_failed_wal IS NOT NULL
+	FROM pg_stat_archiver]);
+
+my $result =
+  $standby2->safe_psql(
+	  'postgres',
+	  "SELECT last_archived_wal, last_failed_wal FROM pg_stat_archiver");
+
+ok($result =~ /^[^|]+\|$/, 'check if archiving proceeds');