Fix for bug #18153 "ALTER/OPTIMIZE/REPAIR on transactional tables corrupt

triggers".

Applying ALTER/OPTIMIZE/REPAIR TABLE statements to transactional table or to
table of any type on Windows caused disappearance of its triggers.
Bug was introduced in 5.0.19 by my fix for bug #13525 "Rename table does not
keep info of triggers" (see comment for sql_table.cc for more info).
.


mysql-test/r/trigger.result:
  Added test-case covering handling of triggers when one does ALTER TABLE which
  should move table to different database.
mysql-test/t/trigger.test:
  Added test-case covering handling of triggers when one does ALTER TABLE which
  should move table to different database.
sql/sql_table.cc:
  mysql_alter_table():
    Removal of strdup() which is no longer necessary allows us to preserve
    nice assumption that "(new_db != db || new_table != table_name) indicates
    that table will be renamed. So now we really can use this condition to
    avoid updating trigger definitions when table is not renamed.
    Note that we can't use (alter_info->flags & ALTER_RENAME) condition instead
    since it can be also true when we do "ALTER TABLE t1 RENAME TO t1".
sql/sql_trigger.cc:
  Table_triggers_list::change_table_name():
    Mentioned assumption that subject table is not renamed to itself in method
    description. Added DBUG_ASSERT() to catch wrong usage of this method.
mysql-test/r/trigger-trans.result:
  New BitKeeper file ``mysql-test/r/trigger-trans.result''
mysql-test/t/trigger-trans.test:
  New BitKeeper file ``mysql-test/t/trigger-trans.test''

mysql-test/r/trigger-trans.result

+drop table if exists t1;
+create table t1 (a varchar(16), b int) engine=innodb;
+create trigger t1_bi before insert on t1 for each row
+begin
+set new.a := upper(new.a);
+set new.b := new.b + 3;
+end|
+select trigger_schema, trigger_name, event_object_schema,
+event_object_table, action_statement from information_schema.triggers
+where event_object_schema = 'test' and event_object_table = 't1';
+trigger_schema	trigger_name	event_object_schema	event_object_table	action_statement
+test	t1_bi	test	t1	begin
+set new.a := upper(new.a);
+set new.b := new.b + 3;
+end
+insert into t1 values ('The Lion', 10);
+select * from t1;
+a	b
+THE LION	13
+optimize table t1;
+Table	Op	Msg_type	Msg_text
+test.t1	optimize	status	OK
+select trigger_schema, trigger_name, event_object_schema,
+event_object_table, action_statement from information_schema.triggers
+where event_object_schema = 'test' and event_object_table = 't1';
+trigger_schema	trigger_name	event_object_schema	event_object_table	action_statement
+test	t1_bi	test	t1	begin
+set new.a := upper(new.a);
+set new.b := new.b + 3;
+end
+insert into t1 values ('The Unicorn', 20);
+select * from t1;
+a	b
+THE LION	13
+THE UNICORN	23
+alter table t1 add column c int default 0;
+select trigger_schema, trigger_name, event_object_schema,
+event_object_table, action_statement from information_schema.triggers
+where event_object_schema = 'test' and event_object_table = 't1';
+trigger_schema	trigger_name	event_object_schema	event_object_table	action_statement
+test	t1_bi	test	t1	begin
+set new.a := upper(new.a);
+set new.b := new.b + 3;
+end
+insert into t1 values ('Alice', 30, 1);
+select * from t1;
+a	b	c
+THE LION	13	0
+THE UNICORN	23	0
+ALICE	33	1
+alter table t1 rename to t1;
+select trigger_schema, trigger_name, event_object_schema,
+event_object_table, action_statement from information_schema.triggers
+where event_object_schema = 'test' and event_object_table = 't1';
+trigger_schema	trigger_name	event_object_schema	event_object_table	action_statement
+test	t1_bi	test	t1	begin
+set new.a := upper(new.a);
+set new.b := new.b + 3;
+end
+insert into t1 values ('The Crown', 40, 1);
+select * from t1;
+a	b	c
+THE LION	13	0
+THE UNICORN	23	0
+ALICE	33	1
+THE CROWN	43	1
+alter table t1 rename to t1, add column d int default 0;
+select trigger_schema, trigger_name, event_object_schema,
+event_object_table, action_statement from information_schema.triggers
+where event_object_schema = 'test' and event_object_table = 't1';
+trigger_schema	trigger_name	event_object_schema	event_object_table	action_statement
+test	t1_bi	test	t1	begin
+set new.a := upper(new.a);
+set new.b := new.b + 3;
+end
+insert into t1 values ('The Pie', 50, 1, 1);
+select * from t1;
+a	b	c	d
+THE LION	13	0	0
+THE UNICORN	23	0	0
+ALICE	33	1	0
+THE CROWN	43	1	0
+THE PIE	53	1	1
+drop table t1;

mysql-test/r/trigger.result

@@ -860,6 +860,37 @@ trigger_schema	trigger_name	event_object_schema	event_object_table	action_statem
 mysqltest	t1_bi	mysqltest	t1	set @a:=new.id
 drop trigger test.t1_bi;
 ERROR HY000: Trigger does not exist
+alter table t1 rename to test.t1;
+ERROR HY000: Trigger in wrong schema
+insert into t1 values (103);
+select @a;
+@a
+103
+select trigger_schema, trigger_name, event_object_schema,
+event_object_table, action_statement from information_schema.triggers
+where event_object_schema = 'test' or event_object_schema = 'mysqltest';
+trigger_schema	trigger_name	event_object_schema	event_object_table	action_statement
+mysqltest	t1_bi	mysqltest	t1	set @a:=new.id
+drop trigger test.t1_bi;
+ERROR HY000: Trigger does not exist
+alter table t1 rename to test.t1, add column val int default 0;
+ERROR HY000: Trigger in wrong schema
+insert into t1 values (104);
+select @a;
+@a
+104
+select trigger_schema, trigger_name, event_object_schema,
+event_object_table, action_statement from information_schema.triggers
+where event_object_schema = 'test' or event_object_schema = 'mysqltest';
+trigger_schema	trigger_name	event_object_schema	event_object_table	action_statement
+mysqltest	t1_bi	mysqltest	t1	set @a:=new.id
+show create table t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `id` int(11) default NULL
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+drop trigger test.t1_bi;
+ERROR HY000: Trigger does not exist
 drop trigger t1_bi;
 drop table t1;
 drop database mysqltest;

mysql-test/t/trigger-trans.test

+# Tests which involve triggers and transactions
+# (or just InnoDB storage engine)
+--source include/have_innodb.inc
+
+--disable_warnings
+drop table if exists t1;
+--enable_warnings
+
+# Test for bug #18153 "OPTIMIZE/ALTER on transactional tables corrupt
+#                      triggers/triggers are lost".
+
+create table t1 (a varchar(16), b int) engine=innodb;
+delimiter |;
+create trigger t1_bi before insert on t1 for each row
+begin
+ set new.a := upper(new.a);
+ set new.b := new.b + 3;
+end|
+delimiter ;|
+select trigger_schema, trigger_name, event_object_schema,
+       event_object_table, action_statement from information_schema.triggers
+       where event_object_schema = 'test' and event_object_table = 't1';
+insert into t1 values ('The Lion', 10);
+select * from t1;
+optimize table t1;
+select trigger_schema, trigger_name, event_object_schema,
+       event_object_table, action_statement from information_schema.triggers
+       where event_object_schema = 'test' and event_object_table = 't1';
+insert into t1 values ('The Unicorn', 20);
+select * from t1;
+alter table t1 add column c int default 0;
+select trigger_schema, trigger_name, event_object_schema,
+       event_object_table, action_statement from information_schema.triggers
+       where event_object_schema = 'test' and event_object_table = 't1';
+insert into t1 values ('Alice', 30, 1);
+select * from t1;
+# Special tricky cases allowed by ALTER TABLE ... RENAME
+alter table t1 rename to t1;
+select trigger_schema, trigger_name, event_object_schema,
+       event_object_table, action_statement from information_schema.triggers
+       where event_object_schema = 'test' and event_object_table = 't1';
+insert into t1 values ('The Crown', 40, 1);
+select * from t1;
+alter table t1 rename to t1, add column d int default 0;
+select trigger_schema, trigger_name, event_object_schema,
+       event_object_table, action_statement from information_schema.triggers
+       where event_object_schema = 'test' and event_object_table = 't1';
+insert into t1 values ('The Pie', 50, 1, 1);
+select * from t1;
+drop table t1;
+
+# End of 5.0 tests

mysql-test/t/trigger.test

@@ -1017,6 +1017,29 @@ select trigger_schema, trigger_name, event_object_schema,
 # There should be no fantom .TRN files 
 --error ER_TRG_DOES_NOT_EXIST
 drop trigger test.t1_bi;
+# Let us also check handling of this restriction in ALTER TABLE ... RENAME
+--error ER_TRG_IN_WRONG_SCHEMA
+alter table t1 rename to test.t1;
+insert into t1 values (103);
+select @a;
+select trigger_schema, trigger_name, event_object_schema,
+       event_object_table, action_statement from information_schema.triggers
+       where event_object_schema = 'test' or event_object_schema = 'mysqltest';
+# Again there should be no fantom .TRN files 
+--error ER_TRG_DOES_NOT_EXIST
+drop trigger test.t1_bi;
+--error ER_TRG_IN_WRONG_SCHEMA
+alter table t1 rename to test.t1, add column val int default 0;
+insert into t1 values (104);
+select @a;
+select trigger_schema, trigger_name, event_object_schema,
+       event_object_table, action_statement from information_schema.triggers
+       where event_object_schema = 'test' or event_object_schema = 'mysqltest';
+# Table definition should not change
+show create table t1;
+# And once again check for fantom .TRN files 
+--error ER_TRG_DOES_NOT_EXIST
+drop trigger test.t1_bi;
 drop trigger t1_bi;
 drop table t1;
 drop database mysqltest;

sql/sql_table.cc

@@ -3831,7 +3831,6 @@ bool mysql_alter_table(THD *thd,char *new_db, char *new_name,
       Win32 and InnoDB can't drop a table that is in use, so we must
       close the original table at before doing the rename
     */
-    table_name=thd->strdup(table_name);		// must be saved
     close_cached_table(thd, table);
     table=0;					// Marker that table is closed
   }

sql/sql_trigger.cc

@@ -1373,6 +1373,7 @@ Table_triggers_list::change_table_name_in_trignames(const char *db_name,
     This method tries to leave trigger related files in consistent state,
     i.e. it either will complete successfully, or will fail leaving files
     in their initial state.
+    Also this method assumes that subject table is not renamed to itself.
 
   RETURN VALUE
     FALSE  Success
@@ -1394,6 +1395,9 @@ bool Table_triggers_list::change_table_name(THD *thd, const char *db,
 
   safe_mutex_assert_owner(&LOCK_open);
 
+  DBUG_ASSERT(my_strcasecmp(table_alias_charset, db, new_db) ||
+              my_strcasecmp(table_alias_charset, old_table, new_table));
+
   if (Table_triggers_list::check_n_load(thd, db, old_table, &table, TRUE))
   {
     result= 1;