branches/zip: row_sel_get_clust_rec_for_mysql(): On the READ UNCOMMITTED

isolation level, do not attempt to access a clustered index record
that has been marked for deletion.  This fixes Issue #433.

Approved by Heikki over the IM.

ChangeLog

+2010-01-13	The InnoDB Team
+
+	* row/row0sel.c:
+	On the READ UNCOMMITTED isolation level, do not attempt to access
+	a clustered index record that has been marked for deletion.  The
+	built-in InnoDB in MySQL 5.1 and earlier would attempt to retrieve
+	a previous version of the record in this case.
+
 2010-01-13	The InnoDB Team
 
 	* buf/buf0buf.c:

row/row0sel.c

@@ -2978,6 +2978,7 @@ row_sel_get_clust_rec_for_mysql(
 
 		if (clust_rec
 		    && (old_vers
+			|| trx->isolation_level <= TRX_ISO_READ_UNCOMMITTED
 			|| rec_get_deleted_flag(rec, dict_table_is_comp(
 							sec_index->table)))
 		    && !row_sel_sec_rec_is_for_clust_rec(