Re: git pull --rebase differs in behavior from git fetch + git rebase

From: Joshua Jensen <jjensen@workspacewhiz.com>
Date: Aug 27, 2010, 15:48 UTC
Message-ID: <4C77DE60.6020809@workspacewhiz.com>
In-Reply-To: <alpine.DEB.2.00.1008270124450.20874@narbuckle.genericorp.net>

  ----- Original Message -----
From: Dave Olszewski
Date: 8/27/2010 2:27 AM

Show 27 quoted lines

> On Thu, 26 Aug 2010, Joshua Jensen wrote:
>
>> I have a case where 'git pull --rebase' does not do the Right Thing 
>> (according to me).
>>
>> If I run 'git rebase origin/master', that rebase does the right 
>> thing, perfectly reapplying my *single* commit on top of the upstream.
>>
>> 'git pull --rebase' ends up reapplying a bunch of much earlier 
>> commits and ends up with a conflict.
>>
>> The documentation for git pull --rebase states: "Instead of a merge, 
>> perform a rebase after fetching. If there is a remote ref for the 
>> upstream branch, and this branch was rebased since last fetched, the 
>> rebase uses that information to avoid rebasing non-local changes."  I 
>> do not understand
>>
>> I'm studying the git-pull script right now, but I have to admit this 
>> is beyond me.  I'm sure if I stare hard enough, I'll get it.
>>
>> I mistakenly have assumed 'git pull' = 'git fetch; git merge' and 
>> that 'git pull --rebase' = 'git fetch; git rebase'.  Does anyone want 
>> to clarify what is really going on?  Unfortunately, I can't publish 
>> the repository in question.
>
> Are you by any chance running a git with commit cf65426de?  If not, give
> it a try and see if it corrects your issue.

I was not, but now I am.

Show 6 quoted lines

> The main difference between "git pull --rebase" and "git fetch && git
> rebase @{u}" is that "git pull --rebase" will attempt to use the reflog
> to find a suitable "upstream" candidate instead of assuming your
> tracking branch is the upstream itself.  This is intended to help
> recover from upstream rebases, but has adverse effects sometimes, which
> commit cf65426de should help with.

Unfortunately, commit cf65426de helps only a little. The 'git pull --rebase' reports "Nothing to do" and moves the master branch to origin/master, leaving behind the commit needing to be rebased.

What else might there be to try? I would like to help with a repro, if possible.

Josh