HIVE-1660.1.patch is the main patch - it create a listPartitionNamesByFilter() method and fixes get_partitions_ps() and get_partition_names_ps() to use the new filter API's. In addition, the patch makes an optimization to use a partition name regex for filtering in cases of equality comparisons.
HIVE-1660_regex.patch was a little experiment to test out the potential speed up from filtering based on a more complete regex of the partition name. For example, for a table partitioned on ds and hr, this patch uses a regex like 'ds=2010-10-01/hr=.*' to find all partitions with a ds='2010-10-01'. For a table with ~5 million partitions and ~15K partitions a day, getting the partitions for a single day took ~1s with this regex patch vs ~10s for the filter patch. Since the table with 5 million partitions was a very unusual case, I didn't think the speedup was worth the additional complexity.