Bug #42152: Race condition in lock_is_table_exclusive()

Detailed revision comments:

r4005 | marko | 2009-01-20 16:22:36 +0200 (Tue, 20 Jan 2009) | 8 lines
branches/5.1: lock_is_table_exclusive(): Acquire kernel_mutex before
accessing table->locks and release kernel_mutex before returning from
the function.  This fixes a portential race condition in the
"commit every 10,000 rows" in ALTER TABLE, CREATE INDEX, DROP INDEX,
and OPTIMIZE TABLE. (Bug #42152)

rb://80 approved by Heikki Tuuri