[RFC PATCH 0/4] git log -g --pretty=format: learns about reflog

This series exposes reflog information to the pretty-printer when using --pretty=format: to git log -g and git rev-list --walk-reflogs, through similar format codes as are used currently.

Thomas Rast mentioned almost as an aside that this would be useful in 

http://article.gmane.org/gmane.comp.version-control.git/108009

and I've wanted to hack this series for a long time, even before that comment, but my first attempts broke stash horribly. Hopefully this version fares better.

I'm a little leery of using commit->util to carry the reflog info, but I didn't see a much better way, without altering the signature of pretty_print_commit to take an optional reflog parameter. The code checks that util is not being used before assigning the reflog to it, so it shouldn't break any existing uses of util of which I am unaware. I confess to having not done an appropriate amount of research into whether my use of util will actually break anything. For what it's worth this patch series doesn't break any existing tests.

One of the things I was hoping to do in the unsuccessful version was to allow the revision walker to use the reflog, but let the commit structures retain their real parents. That way, one could still obtain meaningful information from %p even when walking reflogs, which would be distinct from %rp. It is primarily with this in mind that %rp exists at all. However, as I mentioned, my attempt to change the revision walker broke existing tests, and I didn't have the wherewithal to discover how to correct it. It's possible with the current series that one could simply try to re-parse the commit, but I haven't investigated the feasibility of doing that.

I strongly suspect that there's a cleaner way to do this, but don't really know what that would be, so any comments regarding alternate approaches would be very appreciated. Also, I'm more than happy to write testcases and documentation once there is some agreement about what the preferred implementation is.

Deskin Miller (4):
  Expose reflog_info struct in header
  Add attach_reflog_info
  Attach reflog to commit prior to pretty-printing
  Teach pretty-printer new reflog format codes

 list-objects.c |    3 +++
 log-tree.c     |    3 +++
 pretty.c       |   38 ++++++++++++++++++++++++++++++++++++++
 reflog-walk.c  |   26 +++++++++++++++++++-------
 reflog-walk.h  |   12 ++++++++++++
 5 files changed, 75 insertions(+), 7 deletions(-)