SQL MERGE patches for PostgreSQL Versions

Dear PG hackers,

First my apology if I appear to be a jerk or not following the policy.

I emailed Boxuan Zhai who was in charge of the SQL Merge keyword in
2010 of GSoC but without reply.

I want to apply merge_v201.patch to specific PG version.

It failed saying 1 or 2 of 5 hunk failed.

My question is:
1. Given x old patch of PG, is it possible to know to which PG
version can be applied?
2. If not possible, can someone tell me the general approach to apply
given old patch(merge_v201.patch) to PG.
3. Who was the mentor of SQL Merge of GSoC in 2010 and if present in
this PG Community, can he/she tell me which PG version was applied SQL
Merge?

My goal is to apply SQL Merge pacth into PG successfully and to from
learn the code applied.

Regards,
Zeray