Detailed revision comments:

r6446 | marko | 2010-01-13 17:20:10 +0200 (Wed, 13 Jan 2010) | 3 lines
branches/zip: Treat mem_hash_mutex specially in mutex_free(),
and explicitly free mem_hash_mutex in mem_close().
This fixes the breakage of UNIV_MEM_DEBUG that was filed as Issue #434.