From 835e6fe3e30d534bc5918d1d6c399074a9a13626 Mon Sep 17 00:00:00 2001
From: Michael Banck <michael.banck@credativ.de>
Date: Sun, 19 Mar 2017 10:58:13 +0100
Subject: [PATCH 1/2] Create replication slot in pg_basebackup if requested and
 not yet present.

If a replication slot is explicitly requested, try to create it before
starting to replicate from it.
---
 src/bin/pg_basebackup/pg_basebackup.c        | 15 +++++++++++++++
 src/bin/pg_basebackup/t/010_pg_basebackup.pl | 19 ++++++++++++-------
 2 files changed, 27 insertions(+), 7 deletions(-)

diff --git a/src/bin/pg_basebackup/pg_basebackup.c b/src/bin/pg_basebackup/pg_basebackup.c
index 0a4944d..69ca4be 100644
--- a/src/bin/pg_basebackup/pg_basebackup.c
+++ b/src/bin/pg_basebackup/pg_basebackup.c
@@ -581,6 +581,21 @@ StartLogStreamer(char *startpos, uint32 timeline, char *sysidentifier)
 	else
 		param->temp_slot = temp_replication_slot;
 
+	/*
+	 * Try to create a permanent replication slot if one is specified. Do
+	 * not error out if the slot already exists, other errors are already
+	 * reported by CreateReplicationSlot().
+	 */
+	if (!temp_replication_slot && replication_slot)
+	{
+		if (verbose)
+			fprintf(stderr, _("%s: creating replication slot \"%s\"\n"),
+					progname, replication_slot);
+
+		if (!CreateReplicationSlot(param->bgconn, replication_slot, NULL, true, true))
+			return 1;
+	}
+
 	if (format == 'p')
 	{
 		/*
diff --git a/src/bin/pg_basebackup/t/010_pg_basebackup.pl b/src/bin/pg_basebackup/t/010_pg_basebackup.pl
index 14bd813..29592fd 100644
--- a/src/bin/pg_basebackup/t/010_pg_basebackup.pl
+++ b/src/bin/pg_basebackup/t/010_pg_basebackup.pl
@@ -4,7 +4,7 @@ use Cwd;
 use Config;
 use PostgresNode;
 use TestLib;
-use Test::More tests => 72;
+use Test::More tests => 73;
 
 program_help_ok('pg_basebackup');
 program_version_ok('pg_basebackup');
@@ -246,17 +246,22 @@ $node->command_ok(
 	'pg_basebackup -X stream runs with --no-slot');
 
 $node->command_fails(
-	[ 'pg_basebackup', '-D', "$tempdir/fail", '-S', 'slot1' ],
+	[ 'pg_basebackup', '-D', "$tempdir/fail", '-X', 'none', '-S', 'slot0' ],
 	'pg_basebackup with replication slot fails without -X stream');
-$node->command_fails(
+$node->command_ok(
 	[   'pg_basebackup',             '-D',
 		"$tempdir/backupxs_sl_fail", '-X',
 		'stream',                    '-S',
-		'slot1' ],
-	'pg_basebackup fails with nonexistent replication slot');
+		'slot0' ],
+	'pg_basebackup runs with nonexistent replication slot');
+
+my $lsn = $node->safe_psql('postgres',
+	q{SELECT restart_lsn FROM pg_replication_slots WHERE slot_name = 'slot0'}
+);
+like($lsn, qr!^0/[0-9A-F]{7,8}$!, 'slot is present');
 
 $node->safe_psql('postgres',
-	q{SELECT * FROM pg_create_physical_replication_slot('slot1')});
+       q{SELECT * FROM pg_create_physical_replication_slot('slot1')});
 my $lsn = $node->safe_psql('postgres',
 	q{SELECT restart_lsn FROM pg_replication_slots WHERE slot_name = 'slot1'}
 );
@@ -268,7 +273,7 @@ $node->command_ok(
 $lsn = $node->safe_psql('postgres',
 	q{SELECT restart_lsn FROM pg_replication_slots WHERE slot_name = 'slot1'}
 );
-like($lsn, qr!^0/[0-9A-Z]{7,8}$!, 'restart LSN of slot has advanced');
+like($lsn, qr!^0/[0-9A-F]{7,8}$!, 'restart LSN of slot has advanced');
 
 $node->command_ok(
 	[   'pg_basebackup', '-D', "$tempdir/backupxs_sl_R", '-X',
-- 
2.1.4