Backport TLS 1.2 from OpenJDK 7 - tips and tricks?

[Tiago Daitx]

All-

Hopefully this is the right mailing list to ask about this, otherwise
please let me know where I should post it.

I'm trying to backport the TLS 1.2 support [1] from OpenJDK 7 to
OpenJDK 6, but I'm running into some trouble and I'm wondering what is
the usual way to go about it. I also intent to enable TLS 1.2 by
default (as in JDK-7093640) after I get this stuff backported.

[1] 6916074: Add support for TLS 1.2:
http://hg.openjdk.java.net/jdk7u/jdk7u/jdk/rev/9d6a9f65d2bf

What is the usually the right approach for this?
1. hg import
2. hg transplant
3. compare current files, bring changes that matter

I have been trying option #1, but I'm finding it a bit harsh since
there were backports into OpenJDK 6 that affected the same files as
[1] and those were made *without* backporting any TLS 1.2 stuff. I'm
looking into a lot of rejects and I find it hard to be sure that I'm
getting all the stuff I need for TLS 1.2 support without introducing
bugs.

Option #3 means I will end up putting a few backports into the same
patch, I'm not sure that is allowed and/or if there are any
restrictions. I also have to be sure which commit made what change to
report that. The downside is that I need to then check all the files
from every commit I end up using, otherwise I might miss other
important changes.

I have tried option #2 as well, but either I am doing something wrong
or it does not work as expected - eg. because the repos do not have
the same parent.

I would really appreciate any help.

On a side note, I'm probably not experienced enough with mercurial
(currently I'm much more used to git), so it might just be that I'm
not into the right mindset on how to approach the problem.

Best regards,
Tiago

-- 
Tiago Stürmer Daitx
Software Engineer
tiago.daitx at canonical.com