Detailed revision comments:

r6591 | marko | 2010-02-08 10:06:39 +0200 (Mon, 08 Feb 2010) | 3 lines
branches/zip: row_merge_drop_index(): Remove redundant condition
on SYS_INDEXES.TABLE_ID.  INDEX_ID must be instance-widely unique,
because SYS_FIELDS is not indexed by TABLE_ID.