This crash occured after ALTER TABLE was used on a temporary
transactional table locked by LOCK TABLES. Any later attempts to
execute LOCK/UNLOCK TABLES, caused the server to crash.
The reason for the crash was the list of locked tables would
end up having a pointer to a free'd table instance. This happened
because ALTER TABLE deleted the table without also removing the
table reference from the locked tables list.
This patch fixes the problem by making sure ALTER TABLE also
removes the table from the locked tables list.
Test case added to innodb_mysql.test.
Merge up to sunny.bains@oracle.com-20100625081841-ppulnkjk1qlazh82 .
There are 8 more changesets in mysql-5.1-innodb, but PB2 shows a
failure for a test added in one of them. If that is resolved quickly
then those 8 more changesets will be merged too.
------------------------------------------------------------
revno: 3506
revision-id: sergey.glukhov@sun.com-20100609121718-04mpk5kjxvnrxdu8
parent: sergey.glukhov@sun.com-20100609120734-ndy2281wau9067zv
committer: Sergey Glukhov <Sergey.Glukhov@sun.com>
branch nick: mysql-5.1-innodb
timestamp: Wed 2010-06-09 16:17:18 +0400
message:
Bug#38999 valgrind warnings for update statement in function compare_record()
(InnoDB plugin branch)
@ mysql-test/suite/innodb_plugin/r/innodb_mysql.result
test case
@ mysql-test/suite/innodb_plugin/t/innodb_mysql.test
test case
@ storage/innodb_plugin/row/row0sel.c
init null bytes with default values as they might be
left uninitialized in some cases and these uninited bytes
might be copied into mysql record buffer that leads to
valgrind warnings on next use of the buffer.
Valgrind warning happpens because of uninitialized null bytes.
In row_sel_push_cache_row_for_mysql() function we fill fetch cache
with necessary field values, row_sel_store_mysql_rec() is called
for this and leaves null bytes untouched.
Later row_sel_pop_cached_row_for_mysql() rewrites table record
buffer with uninited null bytes. We can see the problem from the
test case:
At 'SELECT...' we call row_sel_push...->row_sel_store...->row_sel_pop_cached...
chain which rewrites table->record[0] buffer with uninitialized null bytes.
When we call 'UPDATE...' statement, compare_record uses this buffer and
valgrind warning occurs.
The fix is to init null bytes with default values.
