Re: [PATCH 0/2] Reinstate the helpful message when `git pull --rebase` fails

From: Junio C Hamano <gitster@pobox.com>
Date: Oct 9, 2015, 18:55 UTC
Message-ID: <xmqqzizroorx.fsf@gitster.mtv.corp.google.com>
In-Reply-To: <xmqq4mhzq41e.fsf@gitster.mtv.corp.google.com>

Junio C Hamano <gitster@pobox.com> writes:

Show 11 quoted lines

> I looked at the codepath involved, and I do not think that is a
> feasible way forward in this case.  It is not about a "helpful
> message" at all.  You would have to do everything that is done in
> the error codepath in your custom die routine, which does not make
> much sense.
>
> I think the most sensible regression fix as the first step at this
> point is to call it as a separate process, just like the code calls
> "apply" as a separate process for each patch.  Optimization can come
> later when it is shown that it matters---we need to regain
> correctness first.

Don't get me wrong by the above, though.

I would prefer the endgame to be an efficient implementation of merge_recursive_generic(), a function that you can call without you having to worry about it dying.

But the patch in this thread is not that, if I am reading Johannes's description correctly.

And by calling merge_recursive_generic() instead of spawning merge-recursive via run_command(), your GSoC series introduced a regression to "am -3". I'd like to see the regression fixed, and spawning merge-recursive is an obviously correct way to do so.

That is how "am -3" did it before builtin/am.c after all.

Once that is done, the users will not have to worry about this regression, and merge_recursive_generic() implementation can be improved separately. The patch in this thread may serve as a good starting point for that.