Patches produced with format-patch under specific config aren't applicable

Felipe Oliveira Carvalho· Sep 6, 2022, 13:45 UTC · lore

Patches produced with format-patch under specific config aren't applicable

Inbox I have diff.noprefix=true on my ~/.gitconfig

    [diff]
        noprefix = true

I generate a .patch file from the last commit with

    git format-patch HEAD^

Due to noprefix=true, I get this line in the patch file

    diff --git src/filesystem/PhutilProcessQuery.php
src/filesystem/PhutilProcessQuery.php

instead of the default

    diff --git a/src/filesystem/PhutilProcessQuery.php
b/src/filesystem/PhutilProcessQuery.php

So when I try to apply that patch, I get

    $ git apply --check ./0001-my.patch
    error: filesystem/PhutilProcessQuery.php: No such file or directory

In trying to remove the a/ and b/ that apply expects, it removes src/ from the path, then fails to find filesystem/PhutilProcessQuery.php.

As a mitigation, I'm setting diff.noprefix to false, but a more robust solution would be for the format-patch command to ignore this setting as patches are expected to work on repos configured by different people.

git version 2.37.3 -- Felipe

Đoàn Trần Công Danh· Sep 7, 2022, 02:19 UTC · re: Felipe Oliveira Carvalho · lore

Re: Patches produced with format-patch under specific config aren't applicable

On 2022-09-06 10:45:41-0300, Felipe Oliveira Carvalho <felipekde@gmail.com> wrote:

Show 34 quoted lines

> Patches produced with format-patch under specific config aren't applicable
> 
> Inbox
> I have diff.noprefix=true on my ~/.gitconfig
> 
>     [diff]
>         noprefix = true
> 
> I generate a .patch file from the last commit with
> 
>     git format-patch HEAD^
> 
> Due to noprefix=true, I get this line in the patch file
> 
>     diff --git src/filesystem/PhutilProcessQuery.php
> src/filesystem/PhutilProcessQuery.php
> 
> instead of the default
> 
>     diff --git a/src/filesystem/PhutilProcessQuery.php
> b/src/filesystem/PhutilProcessQuery.php
> 
> So when I try to apply that patch, I get
> 
>     $ git apply --check ./0001-my.patch
>     error: filesystem/PhutilProcessQuery.php: No such file or directory
> 
> In trying to remove the a/ and b/ that apply expects, it removes src/
> from the path, then fails to find filesystem/PhutilProcessQuery.php.
> 
> As a mitigation, I'm setting diff.noprefix to false, but a more robust
> solution would be for the format-patch command to ignore this setting
> as patches are expected to work on repos configured by different
> people.

You can use "-p0" with git-am or git-apply to apply such patches.

There's a RFE in the past to add log.noprefix and/or format.noprefix but it seems noone interested enough to work on it [1]

1: https://lore.kernel.org/git/xmqqr1auvs7m.fsf@gitster.g/

-- 
Danh