PT-94 Fixed updates to PK while osc is running

t/pt-online-schema-change/issue-1646713.t

@@ -0,0 +1,100 @@
+#!/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 threads;
+use threads::shared;
+
+use English qw(-no_match_vars);
+use Test::More;
+
+use Data::Dumper;
+use PerconaTest;
+use Sandbox;
+use SqlModes;
+use File::Temp qw/ tempdir /;
+
+plan tests => 2;
+
+require "$trunk/bin/pt-online-schema-change";
+
+my $dp = new DSNParser(opts=>$dsn_opts);
+my $sb = new Sandbox(basedir => '/tmp', DSNParser => $dp);
+
+our ($master_dbh, $master_dsn) = $sb->start_sandbox(
+   server => 'master',
+   type   => 'master',
+   env    => q/FORK="pxc" BINLOG_FORMAT="ROW"/,
+);
+
+if ( !$master_dbh ) {
+   plan skip_all => 'Cannot connect to sandbox master';
+}
+
+# The sandbox servers run with lock_wait_timeout=3 and it's not dynamic
+# so we need to specify --set-vars innodb_lock_wait_timeout=3 else the
+# tool will die.
+my @args       = (qw(--set-vars innodb_lock_wait_timeout=3));
+my $output;
+my $exit_status;
+my $sample  = "t/pt-online-schema-change/samples/";
+
+$sb->load_file('master', "$sample/issue-1646713.sql");
+
+sub start_thread {
+   my ($dsn_opts, $sleep_time) = @_;
+   my $dp = new DSNParser(opts=>$dsn_opts);
+   my $sb = new Sandbox(basedir => '/tmp', DSNParser => $dp);
+   my $dbh = $sb->get_dbh_for('master');
+   diag("Thread started: Sleeping $sleep_time seconds before updating the PK field for row with id=1 in test.sbtest");
+   sleep($sleep_time);
+   $dbh->do("UPDATE `test`.`o1` SET id=0 WHERE id=1");
+   diag("Row updated");
+}
+my $thr = threads->create('start_thread', $dsn_opts, 3);
+$thr->detach();
+threads->yield();
+
+diag("Starting osc. A row will be updated in a different thread.");
+my $dir = tempdir( CLEANUP => 1 );
+$output = output(
+   sub { pt_online_schema_change::main(@args, "$master_dsn,D=test,t=o1",
+         '--execute', 
+         '--alter', "ADD COLUMN c INT",
+         '--chunk-size', '1',
+         ),
+      },
+);
+
+
+like(
+      $output,
+      qr/Successfully altered/s,
+      "bug-1646713 duplicate rows in _t_new for UPDATE t set pk=0 where pk=1",
+);
+
+my $rows = $master_dbh->selectrow_arrayref(
+   "SELECT COUNT(*) FROM `test`.`o1` WHERE id=0");
+is(
+   $rows->[0],
+   1,
+   "bug-1646713 correct value after updating the PK"
+) or diag(Dumper($rows));
+
+threads->exit();
+
+$master_dbh->do("DROP DATABASE IF EXISTS test");
+
+# #############################################################################
+# Done.
+# #############################################################################
+$sb->wipe_clean($master_dbh);
+$sb->stop_sandbox(qw(master)); 
+ok($sb->ok(), "Sandbox servers") or BAIL_OUT(__FILE__ . " broke the sandbox");
+done_testing;