Subject: Re: git am oddity

From: Junio C Hamano <[email-masked]>
Date: Mon, 31 Mar 2014 15:15:22 -0700

Sverre Rabbelier <[email-masked]> writes:

> Hi,
>
> I noticed something very odd with git am, and have been able to narrow
> it down to a minimal example.
>
>  git init tmp
>  cd tmp
>  mkdir -p foo/bar/baz
>  cd foo/bar/baz
>  echo file > file
>  git add file
>  git commit -m "1"
>  echo other > other
>  echo more >> file
>  git add file other
>  git commit -m "my test"
>  git format-patch HEAD~..
>  git reset --hard HEAD~
>  # apply the patch in the current directory, chop off the leading directories
>  git am -3 -p 3 0001-my-test.patch
>  cd ../../..
>  git ls-files
>
> Expected output:
> foo/bar/baz/file
> foo/bar/baz/other
>
> Actual output:
> baz/other # the file addition was applied to the root of the
> repository, instead of the current directory
> foo/bar/baz/file # the file modification was correctly applied, yay
>
> Is this expected behavior?

As you are doing -3 (not the -p3), it would have:

 * noticed that the patch is trying to update "baz/file";

 * noticed that there is no "baz/file" but it could salvage the
   patch by doing a three-way merge, in case that the patch was
   prepared against a tree that moved path "foo/bar/baz" to "baz";
   and

 * such a three-way merge succeeds cleanly for a path whose movement
   was detected correctly.

So it does not look odd at all to me (the use of "-p 3" does look
odd, but I know this is an effort to come up with a minimum example,
so it is understandable that it may look contribed ;-).