Re: history damage in linux.git

From: Linus Torvalds <torvalds@linux-foundation.org>
Date: Apr 21, 2016, 17:00 UTC
Message-ID: <CA+55aFzk4rZFdhOjkPDqFC3_tk4BUvx4-STsY2L_tKMH2FxCCA@mail.gmail.com>
In-Reply-To: <CA+55aFx8hPKKcuwe-HHoO7LHVYLmJ6khndd-OtQotMs3EJzZ0w@mail.gmail.com>

On Thu, Apr 21, 2016 at 9:36 AM, Linus Torvalds <torvalds@linux-foundation.org> wrote:

Show 8 quoted lines

>
> This seems to be a git bug.
>
> That commit aed06b9 can also be described as
>
>     v3.13-rc7~9^2~14^2~42
>
> so describing it as 'v4.6-rc1~9^2~792' is clearly not closer in any way.

Hmm. I think I see what's up. The git distance function has a special hack for preferring first-parent traversal, introduced long long ago with commit ac076c29ae8d ("name-rev: Fix non-shortest description").

Changing that

  #define MERGE_TRAVERSAL_WEIGHT 65535

to be a smaller value makes git find the shorter path.

I do not know what the correct fix is, though.

              Linus