From: Junio C Hamano Date: Mon, 05 Aug 2013 19:16:01 GMT Subject: Re: [PATCH] log: use true parents for diff when walking reflogs Message-ID: <7vd2psj6dq.fsf@alter.siamese.dyndns.org> In-Reply-To: Thomas Rast writes: > The reflog walking logic (git log -g) replaces the true parent list > with the preceding commit in the reflog. This results in bogus commit > diffs when combined with options such as -p; the diff is against the > reflog predecessor, not the parent of the commit. > > Save the true parents on the side, extending the functions from the > previous commit. The diff logic picks them up and uses them to show > the correct diffs. > > We do have to be somewhat careful about repeated calling of > save_parents(), since the reflog may list a commit more than once. We > now store (commit_list*)-1 to distinguish the "not saved yet" and > "root commit" cases. This lets us preserve an empty parent list even > if save_parents() is repeatedly called. > > Suggested-by: Jeff King > Signed-off-by: Thomas Rast > --- > > Jeff King wrote: >> >> Your description (and solution) make a lot of sense to me. Another code >> path that has a similar problem is the "-g" reflog walker. It rewrites >> the parents based on the reflog, and the diffs it produces are mostly >> useless (e.g., try "git stash list -p"). >> >> Should we be applying the same technique there? > > Good point. This is how. It applies on top of the other patch. Thanks. > It doesn't really help for 'git stash list -p', though, because > stashes are merge commits. Now they just don't show anything. > could try 'git stash list -p -m', though. Using --first-parent may be more convenient and useful.