Bug#16878 dump of trigger

 - Pass "in_comment" variable on to new lex in sp_head::reset_lex
 - Add testcases for dumping and reloading trigger without BEGIN/END


mysql-test/r/mysqldump.result:
  Update test result
mysql-test/t/mysqldump.test:
  Add test for dumping trigger without begin/end, and test that the output from mysqldump can be reloaded.
sql/sp_head.cc:
  If already in a comment before parsing a substatement, set in_comment in the new lex as well.
  This will handle cases where the comment starts before the substatement, which is common in 
  output from mysqldump to mask away syntax not supported by earlier versions of MySQL.
  Ex:
  /*!50003 CREATE TRIGGER `tr1` BEFORE INSERT ON `t1` FOR EACH ROW
  set new.created=now() */;
  ^=== sp_head::reset_lex is called when already in comment

mysql-test/r/mysqldump.result

@@ -2611,3 +2611,25 @@ UNLOCK TABLES;
 /*!40111 SET SQL_NOTES=@OLD_SQL_NOTES */;
 
 drop table t1;
+create table t1 (a int, created datetime);
+create table t2 (b int, created datetime);
+create trigger tr1 before insert on t1 for each row set
+new.created=now();
+create trigger tr2 after insert on t1
+for each row
+begin
+insert into t2 set b=new.a and created=new.created;
+end|
+drop trigger tr1;
+drop trigger tr2;
+drop table t1, t2;
+show triggers;
+Trigger	Event	Table	Statement	Timing	Created	sql_mode	Definer
+tr1	INSERT	t1	set
+new.created=now()	BEFORE	#		root@localhost
+tr2	INSERT	t1	begin
+insert into t2 set b=new.a and created=new.created;
+end	AFTER	#		root@localhost
+drop trigger tr1;
+drop trigger tr2;
+drop table t1, t2;

mysql-test/t/mysqldump.test

@@ -1036,3 +1036,33 @@ insert into t1 values ('','');
 drop table t1;
 
 # End of 4.1 tests
+
+#
+# Bug #16878 dump of trigger
+#
+
+create table t1 (a int, created datetime);
+create table t2 (b int, created datetime);
+create trigger tr1 before insert on t1 for each row set
+new.created=now();
+delimiter |;
+create trigger tr2 after insert on t1
+for each row
+begin
+  insert into t2 set b=new.a and created=new.created;
+end|
+delimiter ;|
+
+# dump table and trigger
+--exec $MYSQL_DUMP test > var/tmp/bug16878.sql
+drop trigger tr1;
+drop trigger tr2;
+drop table t1, t2;
+
+# reload dump
+--exec $MYSQL test < var/tmp/bug16878.sql
+--replace_column 6 #
+show triggers;
+drop trigger tr1;
+drop trigger tr2;
+drop table t1, t2;

sql/sp_head.cc

@@ -1584,6 +1584,8 @@ sp_head::reset_lex(THD *thd)
   sublex->trg_table_fields.empty();
   sublex->sp_lex_in_use= FALSE;
 
+  sublex->in_comment= oldlex->in_comment;
+
   /* Reset type info. */
 
   sublex->charset= NULL;