Re: [PATCH] Additional merge-base tests

From: Junio C Hamano <junkio@cox.net>
Date: Jul 4, 2006, 05:47 UTC
Message-ID: <7v3bdhoraa.fsf@assigned-by-dhcp.cox.net>
In-Reply-To: <44A9E6AE.10508@gmail.com>

A Large Angry SCM <gitzilla@gmail.com> writes:

Show 13 quoted lines

> This demonstrates a problem with git-merge-base.
>  
> +# Setup for second test set
> +#
> +#   PL  PR
> +#  /  \/  \
> +# L2  C2  R2
> +# |   |   |
> +# L1  C1  R1
> +# |   |   |
> +# L0  C0  R0
> +#   \ |  /
> +#     S

Cute.

This is a good demonstration that merge-base may not give you minimal set for pathological cases. If you want to be through you could traverse everything to make sure we do not say 'S' is relevant, but that is quite expensive, so I think there will always be artifacts of horizon effect like this no matter how you try to catch it (didn't I keep saying that already?).

However, I do not think it is really a "problem". At least what "merge-base --all" did not miss any, that should be OK.

I think the practical way to proceed is to say that the test condition should really check that we do not _omit_ C2 in the merge-base --all output.