Subject: Re: rebasing merges

From: Johannes Sixt <[email-masked]>
Date: Tue, 23 Sep 2008 09:52:50 +0200

Samuel Tardieu schrieb:
>>>>>> "Johannes" == Johannes Sixt <[email-masked]> writes:
> 
> Johannes> i.e. linearized history without merges.
> 
> A few days ago, I had a question in my team quite similar to Stephen
> concern. A developer had performed a merge of a complex feature and
> was ready to commit it
> 
>   --o--o--o--o--X        <-- origin
>      \           \
>       A--B--C--D--E      <-- master
> 
> when he realized that someone just pushed another change on origin
> while he was doing the complicating merge (with lots of conflicts to
> resolve). The configuration was then:
> 
>   --o--o--o--o--X--Y     <-- origin
>      \           \
>       A--B--C--D--E      <-- master
> 
> He would have wanted to have the merge rebased on E and Y instead of E
> and X before pushing, without going through all the conflicts
> resolution again (he didn't have "rerere" enabled).

If you mean "merge", and you are willing to keep E, then you do another
merge to get this history:

  --o--o--o--o--X--Y     <-- origin
     \           \  \
      A--B--C--D--E--F   <-- master

and the previous conflicts will not show up again. But if you do not want
E to show up in the history, like this:

  --o--o--o--o--X--Y     <-- origin
     \              \
      A--B--C--D-----F   <-- master

then you will have to resolve all conflicts again. Of course, you can keep
 E in a temporary branch, and you can selectively check out files from
that tree to safe some work, but whether this is possible depends on the
changes that Y introduces.

If you mean "rebase", then you get this after the first rebase:

  --o--o--o--o--X--Y               <-- origin
                 \
                  A'--B'--C'--D'   <-- master

Then you can rebase again to get this:

  --o--o--o--o--X--Y                  <-- origin
                    \
                     A"--B"--C"--D'   <-- master

at which time you don't see the old conflicts again.

-- Hannes