Re: [PATCH 3/3] diffstat generation in hooks--update was passing "^baserev" to git-diff-tree

From: Johannes Sixt <j.sixt@eudaptics.com>
Date: Feb 13, 2007, 15:37 UTC
Message-ID: <45D1DB57.65433549@eudaptics.com>
In-Reply-To: <200702131424.21665.andyparkins@gmail.com>

Andy Parkins wrote:

> -                       echo "Diffstat:"
> -                       git-diff-tree --no-color --stat -M -C --find-copies-harder $newrev ^$baserev
> +                       echo "Diffstat against $baserev:"
> +                       git-diff-tree --no-color --stat -M -C --find-copies-harder $newrev $baserev

Shouldn't that be "... $baserev $newrev"? But read on.

I cannot entirely follow the reasoning of the comment above this part, which says:

# Now the problem is for cases like this: # * --- * --- * --- * (oldrev) # \ # * --- * --- * (newrev) # i.e. there is no guarantee that newrev is a strict subset # of oldrev - (would have required a force, but that's allowed). # So, we can't simply say rev-list $oldrev..$newrev. Instead # we find the common base of the two revs and list from there

git rev-list $oldrev..$newrev

is exactly what you want in this case. The stunt with $baserev is not necessary, and it may even be wrong if there is more than one merge-base. $oldrev..$newrev will be correct even in this case.

You still need to derive a merge-base, but only to detect the forced update and to format the message. Then you should use --not $baserev instead of ^$baserev just in case there is more than one merge-base.

-- Hannes