Add failing test.

t/pt-table-checksum/bugs.t

@@ -0,0 +1,82 @@
+#!/usr/bin/env perl
+
+BEGIN {
+   die "The PERCONA_TOOLKIT_BRANCH environment variable is not set.\n"
+      unless $ENV{PERCONA_TOOLKIT_BRANCH} && -d $ENV{PERCONA_TOOLKIT_BRANCH};
+   unshift @INC, "$ENV{PERCONA_TOOLKIT_BRANCH}/lib";
+};
+
+use strict;
+use warnings FATAL => 'all';
+use English qw(-no_match_vars);
+use Test::More;
+
+# Hostnames make testing less accurate.  Tests need to see
+# that such-and-such happened on specific slave hosts, but
+# the sandbox servers are all on one host so all slaves have
+# the same hostname.
+$ENV{PERCONA_TOOLKIT_TEST_USE_DSN_NAMES} = 1;
+
+use Data::Dumper;
+use PerconaTest;
+use Sandbox;
+
+# Fix @INC because pt-table-checksum uses subclass OobNibbleIterator.
+shift @INC;  # our unshift (above)
+shift @INC;  # PerconaTest's unshift
+require "$trunk/bin/pt-table-checksum";
+
+my $dp = new DSNParser(opts=>$dsn_opts);
+my $sb = new Sandbox(basedir => '/tmp', DSNParser => $dp);
+my $master_dbh = $sb->get_dbh_for('master');
+my $slave_dbh  = $sb->get_dbh_for('slave1');
+
+if ( !$master_dbh ) {
+   plan skip_all => 'Cannot connect to sandbox master';
+}
+elsif ( !$slave_dbh ) {
+   plan skip_all => 'Cannot connect to sandbox slave1';
+}
+else {
+   plan tests => 2;
+}
+
+# The sandbox servers run with lock_wait_timeout=3 and it's not dynamic
+# so we need to specify --lock-wait-timeout=3 else the tool will die.
+my $master_dsn = 'h=127.1,P=12345,u=msandbox,p=msandbox';
+my @args       = ($master_dsn, qw(--lock-wait-timeout 3));
+my $output;
+my $exit_status;
+my $sample  = "t/pt-table-checksum/samples/";
+
+# ############################################################################
+# https://bugs.launchpad.net/percona-toolkit/+bug/995274
+# Can't use an undefined value as an ARRAY reference at pt-table-checksum
+# line 2206
+# ############################################################################
+$sb->load_file('master', "$sample/undef-arrayref-bug-995274.sql");
+PerconaTest::wait_for_table($slave_dbh, "test.GroupMembers", "id=493076");
+
+$output = output(
+   sub { $exit_status = pt_table_checksum::main(@args, qw(-d test)) },
+   stderr => 1,
+);
+
+is(
+   $exit_status,
+   0,
+   "Bug 995274: zero exit status"
+);
+
+cmp_ok(
+   PerconaTest::count_checksum_results($output, 'rows'),
+   '>',
+   1,
+   "Bug 995274: checksummed rows"
+);
+
+# #############################################################################
+# Done.
+# #############################################################################
+$sb->wipe_clean($master_dbh);
+exit;