Re: git rebase --preserve-merges seems to not work

From: Joshua Jensen <jjensen@workspacewhiz.com>
Date: Sep 9, 2010, 06:26 UTC
Message-ID: <4C887E22.5050303@workspacewhiz.com>
In-Reply-To: <20100909055104.GA21004@atjola.homenet>

  ----- Original Message -----
From: Björn Steinbrink
Date: 9/8/2010 11:51 PM

Show 24 quoted lines

>> $ git lg --all
>> * 2c93a8a - (HEAD) c (11 seconds ago)
>> * 2b98bc6 - b (11 seconds ago)
>> * 6abf527 - (d) d (3 minutes ago)
>> | *   472fd93 - (bc-merge) Merge commit 'c' into HEAD (74 seconds ago)
>> | |\
>> |/ /
>> | * d132c87 - (c) c (3 minutes ago)
>> | * 4a88fd1 - b (3 minutes ago)
>> |/
>> * b576660 - (a, master) a (4 minutes ago)
> What you actually wanted to replay is just the first-parent history,
> redoing the merges with their respective original second parent.
> Jonathan (Cc'ed) had the same problem about a month ago.
>
> The "first parent" thing isn't that well defined, criss-cross merges
> combined with some unfortunate fast-forwards will easily make the
> first-parent history become the one that you didn't mean (ask any
> git-svn users that dared to use "git merge" without fully understanding
> how git-svn uses the history ;-)), but it works in this special case.
> And with that special case in mind (and admittedly probably not thinking
> much further) I came up with this patch a few years ago:
>
> http://marc.info/?l=git&m=119379735525213&w=2

I hand merged your change in to my Git installation. There is one part of git-rebase--interactive that looks entirely different, so I would need to look back through the history to determine how to properly apply it.

The good news is the patch does exactly what I want in this simple case. I will have to try it on some more complicated hierarchies to see what the end result is.

It's curious... whenever I ask around about issue X or feature Y, a previously submitted patch can generally be found in the list archives. :)

Josh