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

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

quoted

$ 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