Add new simple TAP test for tablespaces.

The tablespace tests in the main regression tests have been changed to
use "in-place" tablespaces, so that they work when streamed to a replica
on the same host.  Add a new TAP test that exercises tablespaces with
absolute paths, for coverage.

Reviewed-by: Andres Freund <andres@anarazel.de>
Reviewed-by: Michael Paquier <michael@paquier.xyz>
Discussion: https://postgr.es/m/CA%2BhUKGKpRWQ9SxdxxDmTBCJoR0YnFpMBe7kyzY8SUQk%2BHeskxg%40mail.gmail.com

src/test/modules/test_misc/t/002_tablespace.pl

@@ -0,0 +1,96 @@
+# Simple tablespace tests that can't be replicated on the same host
+# due to the use of absolute paths, so we keep them out of the regular
+# regression tests.
+
+use strict;
+use warnings;
+use PostgreSQL::Test::Cluster;
+use PostgreSQL::Test::Utils;
+use Test::More tests => 20;
+
+my $node = PostgreSQL::Test::Cluster->new('main');
+$node->init;
+$node->start;
+
+# Create a couple of directories to use as tablespaces.
+my $TS1_LOCATION = $node->basedir() . "/ts1";
+mkdir($TS1_LOCATION);
+my $TS2_LOCATION = $node->basedir() . "/ts2";
+mkdir($TS2_LOCATION);
+
+my $result;
+
+# Create a tablespace with an absolute path
+$result = $node->psql('postgres',
+	"CREATE TABLESPACE regress_ts1 LOCATION '$TS1_LOCATION'");
+ok($result == 0, 'create tablespace with absolute path');
+
+# Can't create a tablespace where there is one already
+$result = $node->psql('postgres',
+	"CREATE TABLESPACE regress_ts1 LOCATION '$TS1_LOCATION'");
+ok($result != 0, 'clobber tablespace with absolute path');
+
+# Create table in it
+$result = $node->psql('postgres',
+	"CREATE TABLE t () TABLESPACE regress_ts1");
+ok($result == 0, 'create table in tablespace with absolute path');
+
+# Can't drop a tablespace that still has a table in it
+$result = $node->psql('postgres',
+	"DROP TABLESPACE regress_ts1");
+ok($result != 0, 'drop tablespace with absolute path');
+
+# Drop the table
+$result = $node->psql('postgres', "DROP TABLE t");
+ok($result == 0, 'drop table in tablespace with absolute path');
+
+# Drop the tablespace
+$result = $node->psql('postgres', "DROP TABLESPACE regress_ts1");
+ok($result == 0, 'drop tablespace with absolute path');
+
+# Create two absolute tablespaces and two in-place tablespaces, so we can
+# testing various kinds of tablespace moves.
+$result = $node->psql('postgres',
+	"CREATE TABLESPACE regress_ts1 LOCATION '$TS1_LOCATION'");
+ok($result == 0, 'create tablespace 1 with absolute path');
+$result = $node->psql('postgres',
+	"CREATE TABLESPACE regress_ts2 LOCATION '$TS2_LOCATION'");
+ok($result == 0, 'create tablespace 2 with absolute path');
+$result = $node->psql('postgres',
+	"SET allow_in_place_tablespaces=on; CREATE TABLESPACE regress_ts3 LOCATION ''");
+ok($result == 0, 'create tablespace 3 with in-place directory');
+$result = $node->psql('postgres',
+	"SET allow_in_place_tablespaces=on; CREATE TABLESPACE regress_ts4 LOCATION ''");
+ok($result == 0, 'create tablespace 4 with in-place directory');
+
+# Create a table and test moving between absolute and in-place tablespaces
+$result = $node->psql('postgres',
+	"CREATE TABLE t () TABLESPACE regress_ts1");
+ok($result == 0, 'create table in tablespace 1');
+$result = $node->psql('postgres',
+	"ALTER TABLE t SET tablespace regress_ts2");
+ok($result == 0, 'move table abs->abs');
+$result = $node->psql('postgres',
+	"ALTER TABLE t SET tablespace regress_ts3");
+ok($result == 0, 'move table abs->in-place');
+$result = $node->psql('postgres',
+	"ALTER TABLE t SET tablespace regress_ts4");
+ok($result == 0, 'move table in-place->in-place');
+$result = $node->psql('postgres',
+	"ALTER TABLE t SET tablespace regress_ts1");
+ok($result == 0, 'move table in-place->abs');
+
+# Drop everything
+$result = $node->psql('postgres',
+	"DROP TABLE t");
+ok($result == 0, 'create table in tablespace 1');
+$result = $node->psql('postgres', "DROP TABLESPACE regress_ts1");
+ok($result == 0, 'drop tablespace 1');
+$result = $node->psql('postgres', "DROP TABLESPACE regress_ts2");
+ok($result == 0, 'drop tablespace 2');
+$result = $node->psql('postgres', "DROP TABLESPACE regress_ts3");
+ok($result == 0, 'drop tablespace 3');
+$result = $node->psql('postgres', "DROP TABLESPACE regress_ts4");
+ok($result == 0, 'drop tablespace 4');
+
+$node->stop;