Use new tbl indexes to create delete trigger.

bin/pt-online-schema-change

@@ -7857,6 +7857,22 @@ sub main {
                      keys %$orig_cols;
    PTDEBUG && _d('Common columns', @common_cols);
 
+   # Find a pk or unique index to use for the delete trigger.  can_nibble()
+   # above returns an index, but NibbleIterator will use non-unique indexes,
+   # so we have to do this again here.
+   my $indexes = $new_tbl->{tbl_struct}->{keys}; # brevity
+   foreach my $index ( $tp->sort_indexes($new_tbl->{tbl_struct}) ) {
+      if ( $index eq 'PRIMARY' || $indexes->{$index}->{is_unique} ) {
+         PTDEBUG && _d('Delete trigger index:', Dumper($index));
+         $new_tbl->{del_index} = $index;
+         last;
+      }
+   }
+   if ( !$new_tbl->{del_index} ) {
+      die "The new table $new_tbl->{name} does not have a PRIMARY KEY "
+        . "or a unique index which is required for the DELETE trigger.\n";
+   }
+
    # ########################################################################
    # Step 3: Create the triggers to capture changes on the original table and
    # apply them to the new table.
@@ -8651,22 +8667,6 @@ sub check_orig_table {
       die "Cannot chunk the original table $orig_tbl->{name}: $EVAL_ERROR\n";
    }
 
-   # Find a pk or unique index to use for the delete trigger.  can_nibble()
-   # above returns an index, but NibbleIterator will use non-unique indexes,
-   # so we have to do this again here.
-   my $indexes = $orig_tbl->{tbl_struct}->{keys}; # brevity
-   foreach my $index ( $tp->sort_indexes($orig_tbl->{tbl_struct}) ) {
-      if ( $index eq 'PRIMARY' || $indexes->{$index}->{is_unique} ) {
-         PTDEBUG && _d('Delete trigger index:', Dumper($index));
-         $orig_tbl->{del_index} = $index;
-         last;
-      }
-   }
-   if ( !$orig_tbl->{del_index} ) {
-      die "The original table $orig_tbl->{name} does not have a PRIMARY KEY "
-        . "or a unique index which is required for the DELETE trigger.\n";
-   }
-
    return;  # success
 }
 
@@ -8915,8 +8915,8 @@ sub create_triggers {
    # To be safe, the delete trigger must specify all the columns of the
    # primary key/unique index.  We use null-safe equals, because unique
    # unique indexes can be nullable.
-   my $tbl_struct     = $orig_tbl->{tbl_struct};
+   my $tbl_struct     = $new_tbl->{tbl_struct};
-   my $del_index      = $orig_tbl->{del_index};
+   my $del_index      = $new_tbl->{del_index};
    my $del_index_cols = join(" AND ",
                            map {
                               my $col = $q->quote($_);

t/pt-online-schema-change/bugs.t

@@ -77,7 +77,7 @@ $sb->load_file('master', "$sample/bug-1002448.sql");
 
 
 unlike $output,
-    qr/\QThe original table `test1002448`.`table_name` does not have a PRIMARY KEY or a unique index which is required for the DELETE trigger/,
+    qr/\QThe new table `test1002448`.`_table_name_new` does not have a PRIMARY KEY or a unique index which is required for the DELETE trigger/,
     "Bug 1002448: mistakenly uses indexes instead of keys";
 
 # ############################################################################
@@ -193,6 +193,48 @@ is_deeply(
 
 $master_dbh->do(q{DROP DATABASE IF EXISTS `bug_1041372`});
 
+# ############################################################################
+# https://bugs.launchpad.net/percona-toolkit/+bug/1062324
+# pt-online-schema-change sets bad DELETE trigger when changing Primary Key
+# ############################################################################
+$sb->load_file('master', "$sample/del-trg-bug-1062324.sql");
+
+{
+   # pt-osc has no --no-drop-triggers option, so we hijack its sub.
+   no warnings;
+   local *pt_online_schema_change::drop_triggers = sub { return };
+
+   # Run the tool but leave the original and new tables as-is,
+   # and leave the triggers.
+   ($output, $exit_status) = full_output(
+      sub { pt_online_schema_change::main(@args,
+         "$master_dsn,D=test,t=t1",
+         "--alter", "drop key 2bpk, drop key c3, drop primary key, drop c1, add primary key (c2, c3(4)), add key (c3(4))",
+         qw(--execute --no-drop-new-table --no-swap-tables)) },
+   );
+
+   # Since _t1_new no longer has the c1 column, the bug caused this
+   # query to throw "ERROR 1054 (42S22): Unknown column 'test._t1_new.c1'
+   # in 'where clause'".
+   eval {
+      $master_dbh->do("DELETE FROM test.t1 WHERE c1=1");
+   };
+   is(
+      $EVAL_ERROR,
+      "",
+      "No delete trigger error after altering PK (bug 1062324)"
+   ) or diag($output);
+
+   # The original row was (c1,c2,c3) = (1,1,1).  We deleted where c1=1,
+   # so the row where c2=1 AND c3=1 should no longer exist.
+   my $row = $master_dbh->selectrow_arrayref("SELECT * FROM test._t1_new WHERE c2=1 AND c3=1");
+   is(
+      $row,
+      undef,
+      "Delete trigger works after altering PK (bug 1062324)"
+   );
+}
+
 # #############################################################################
 # Done.
 # #############################################################################

t/pt-online-schema-change/samples/del-trg-bug-1062324.sql

@@ -0,0 +1,24 @@
+drop database if exists test;
+create database test;
+use test;
+
+CREATE TABLE `t1` (
+  `c1` bigint(20) unsigned NOT NULL AUTO_INCREMENT,
+  `c2` bigint(20) unsigned DEFAULT NULL,
+  `c3` binary(20) DEFAULT NULL,
+  PRIMARY KEY (`c1`),
+  UNIQUE KEY `2bpk` (`c2`,`c3`),
+  KEY `c3` (`c3`)
+) ENGINE=InnoDB;
+
+INSERT INTO t1 VALUES
+  (null, 1, 1),
+  (null, 1, 2),
+  (null, 1, 3),
+  (null, 1, 4),
+  (null, 1, 5),
+  (null, 2, 1),
+  (null, 2, 2),
+  (null, 2, 3),
+  (null, 2, 4),
+  (null, 2, 5);

t/pt-online-schema-change/sanity_checks.t

@@ -92,8 +92,8 @@ $master_dbh->do("ALTER TABLE pt_osc.t DROP INDEX c");
 );
 
 like( $output,
-   qr/`pt_osc`.`t` does not have a PRIMARY KEY or a unique index/,
+   qr/`pt_osc`.`_t_new` does not have a PRIMARY KEY or a unique index/,
-   "Original table must have a PK or unique index"
+   "New table must have a PK or unique index"
 );
 
 # #############################################################################