MySQL patches by Codership

lp:1312618: follow up patch to fix a segfault

Series 5.5
Bug #1334331

Bug #1334331 reported by Nirbhay Choubey on 2014-06-25

This bug affects 1 person

	Status	Importance	Assigned to	Milestone
MySQL patches by Codership	Status tracked in 5.6
5.5	Fix Committed	Undecided	Yan Zhang	MySQL patches by Codership 5.5.38-25.11
5.6	Fix Released	Undecided	Yan Zhang	MySQL patches by Codership 5.6.21-25.9
Percona XtraDB Cluster moved to https://jira.percona.com/projects/PXC	Status tracked in 5.6
5.5	Fix Released	High	Unassigned	Percona XtraDB Cluster moved to https://jira.percona.com/projects/PXC 5.5.39-25.11
5.6	Fix Released	High	Unassigned	Percona XtraDB Cluster moved to https://jira.percona.com/projects/PXC 5.6.19-25.6

Bug Description

http://bazaar.launchpad.net/~codership/codership-mysql/wsrep-5.5/revision/3994

Suggested fix:

=== modified file 'sql/event_data_objects.cc'
--- sql/event_data_objects.cc 2014-06-19 22:48:20 +0000
+++ sql/event_data_objects.cc 2014-06-25 15:22:01 +0000
@@ -1473,20 +1473,23 @@
thd->tx_read_only= false;

#ifdef WITH_WSREP
- // sql_print_information("sizeof(LEX) = %d", sizeof(struct LEX));
- // sizeof(LEX) = 4512, so it's relatively safe to allocate it on stack.
- LEX lex;
- lex.sql_command = SQLCOM_DROP_EVENT;
- thd->lex = &lex;
- WSREP_TO_ISOLATION_BEGIN(WSREP_MYSQL_DB, NULL, NULL);
+ if (WSREP(thd)) {
+ // sql_print_information("sizeof(LEX) = %d", sizeof(struct LEX));
+ // sizeof(LEX) = 4512, so it's relatively safe to allocate it on stack.
+ LEX *old_lex= thd->lex, new_lex;
+ new_lex.sql_command= SQLCOM_DROP_EVENT;
+ thd->lex= &new_lex;
+ WSREP_TO_ISOLATION_BEGIN(WSREP_MYSQL_DB, NULL, NULL);
+ thd->lex= old_lex;
+ }
#endif
-
+
ret= Events::drop_event(thd, dbname, name, FALSE);

-#ifdef WITH_WSREP
+#ifdef WITH_WSREP
       WSREP_TO_ISOLATION_END;
   error:
-#endif
+#endif
       thd->tx_read_only= save_tx_read_only;
       thd->security_ctx->master_access= saved_master_access;
     }