Re: [PATCH] A utility to perform merges between Subversion branches using git

From: Junio C Hamano <junkio@cox.net>
Date: Apr 27, 2007, 22:38 UTC
Message-ID: <7v3b2lmoi7.fsf@assigned-by-dhcp.cox.net>
In-Reply-To: <7vy7kephg8.fsf@assigned-by-dhcp.cox.net>

Junio C Hamano <junkio@cox.net> writes:

Show 10 quoted lines

>> +if test "$Status" = "committed"; then
>> +	git svn dcommit || \
>> +		die "Can't commit to Subversion"
>> +
>> +	# dcommit will update our current HEAD to point to the newly committed
>> +	# svn revision. Update grafts file to tell git that it's a merge.
>> +	NewRevision="`git rev-list --max-count=1 HEAD`"
>> +	echo "$NewRevision $OldHead $RevToMerge" >> $GitDir/info/grafts
>
> This graft look very yucky, and would not scale.

Style issues aside...

I do not know what dcommit is supposed to do, but I wonder if that graft part can be folded into it. Even if git-svn cannot deal with merges that happen on the svn side, assuming if your grafting solution works, it indicates that git-svn itself does not have trouble seeing a merge commit on git side, as its invocation of "git-rev-list --parents" would show that the commit you grafted an extra parent to has two parents and git-svn needs to be able to deal with it.

The command sequence in your contrib script is:

 - make a commit on top of git-svn managed head by hand,
   recording what should have happened if git-svn knew how to
   merge two svn branches;

 - make svn dcommit to record it to svn side, and let it make an
   extra commit to mark the synchronization between git-svn
   managed head and svn repository;

 - pretend that the synchronization commit svn dcommit made has
   an extra commit, which is what you created by hand;

So perhaps you can add an option "git-svn dcommit --merge $OldHead $RevToMerge" that does whatever it usually does and record the resulting commit as a merge between these two commits?