Bug#13635833: MULTIPLE CRASHES IN FOREIGN KEY CODE WITH CONCURRENT DDL/DML

      
There are two threads.  In one thread, dml operation is going on 
involving cascaded update operation.  In another thread, alter 
table add foreign key constraint is happening.  Under these 
circumstances, it is possible for the dml thread to access a 
dict_foreign_t object that has been freed by the ddl thread.  
The debug sync test case provides the sequence of operations.  
Without fix, the test case will crash the server (because of 
newly added assert).  With fix, the alter table stmt will return 
an error message.  
      
Backporting the fix from MySQL 5.5 to 5.1

rb:961
rb:947

1 files changed, 5 insertions, 1 deletions

diff --git a/mysys/my_handler_errors.h b/mysys/my_handler_errors.h
index 44c79466e84..1710ac81395 100644
--- a/mysys/my_handler_errors.h
+++ b/mysys/my_handler_errors.h
@@ -78,6 +78,10 @@ static const char *handler_error_messages[]=
   "Got a fatal error during initialzaction of handler",
   "File to short; Expected more data in file",
   "Read page with wrong checksum",
-  "Too many active concurrent transactions"
+  "Too many active concurrent transactions",
+  "",
+  "",
+  "",
+  "Table is being used in foreign key check" /* HA_ERR_TABLE_IN_FK_CHECK */
 };