Re: odd behavior with git-rebase

From: Phil Hord <phil.hord@gmail.com>
To: Jeff King <peff@peff.net>
Cc: Neil Horman <nhorman@tuxdriver.com>, git@vger.kernel.org
Subject: Re: odd behavior with git-rebase
Date: Mon, 26 Mar 2012 14:31:05 -0400	[thread overview]
Message-ID: <CABURp0qeJEwELpg_YKxn9Ghb6EMphrwwfueM2XCqua3X_dacdA@mail.gmail.com> (raw)
In-Reply-To: <20120323195455.GB15063@sigill.intra.peff.net>

On Fri, Mar 23, 2012 at 3:54 PM, Jeff King <peff@peff.net> wrote:
> On Fri, Mar 23, 2012 at 02:52:05PM -0400, Neil Horman wrote:
>
>>       I hit a strange problem with git rebase and I can't quite decide if its
>> a design point of the rebase command, or if its happening in error.  When doing
>> upstream backports of various kernel components I occasionally run accross
>> commits that, for whatever reason, I don't want/need or can't backport.  When
>> that happens, I insert an empty commit in my history noting the upstream commit
>> hash and the reasoning behind why I skipped it (I use git commit -c <hash>
>> --allow-empty).  If I later rebase this branch, I note that all my empty commits
>> fail indicating the commit cannot be applied.  I can of course do another git
>> commit --allow-empty -c <hash>; git rebase --continue, and everything is fine,
>> but I'd rather it just take the empty commit in the rebase if possible.
>
> I think it is even odder than that. If you use plain rebase, the empty
> commits are silently omitted. If you do an interactive rebase, you get
> the "could not apply" message (and just doing a "continue" creates some
> funny error messages and ends up omitting the commit).

Coincidentally I ran into this same behavior this week.  But what
bothered me about it was the messages git gave me.  The empty commit
gave me cherry-pick hints instead of rebase ones, including advising
me to "use 'git reset'" to resolve the problem if I don't want this
commit after all.

$ git rebase -i HEAD~10
...
The previous cherry-pick is now empty, possibly due to conflict resolution.
If you wish to commit it anyway, use:

    git commit --allow-empty

Otherwise, please use 'git reset'
# Not currently on any branch.
nothing to commit (working directory clean)
Could not apply d513504... Some commit message

I'm not sure if this is the norm or if it's a result of some other
things I did in this sequence.  But I've seen it several times now.
I've only tested it on 1.7.10 versions, including RC2.

Phil