git apply fails silently when on the wrong directory

git apply fails silently when on the wrong directory

[Ernesto Alfonso]

I recently ran into a similar issue as described here:

https://stackoverflow.com/questions/24821431/git-apply-patch-fails-silently-no-errors-but-nothing-happens

I was using the alias:

alias ganw='git diff -U0 -w --no-color "$@" | git apply --cached --ignore-whitespace --unidiff-zero -'

to stage non-whitespace changes, but I was not in the root directory and
the changes were not being applied. I broke down the command to discover
the 'git apply' part of the pipe was silently failing to apply anything,
exiting 0 without even a warning.

The exit status and lack of warning is terribly misleading, I imagine
this would be the cause of subtle bugs in automated scripts. 

Is this expected behaviour?

Thanks,

Ernesto

Re: git apply fails silently when on the wrong directory

[Ernesto Alfonso]

Also, has there been a feature request for a '-w' option to 'git add',
analogous to the same option in 'git diff'?

Ernesto Alfonso <erjoalgo@gmail.com> writes:

> I recently ran into a similar issue as described here:
>
> https://stackoverflow.com/questions/24821431/git-apply-patch-fails-silently-no-errors-but-nothing-happens
>
> I was using the alias:
>
> alias ganw='git diff -U0 -w --no-color "$@" | git apply --cached --ignore-whitespace --unidiff-zero -'
>
> to stage non-whitespace changes, but I was not in the root directory and
> the changes were not being applied. I broke down the command to discover
> the 'git apply' part of the pipe was silently failing to apply anything,
> exiting 0 without even a warning.
>
> The exit status and lack of warning is terribly misleading, I imagine
> this would be the cause of subtle bugs in automated scripts. 
>
> Is this expected behaviour?
>
> Thanks,
>
> Ernesto

Re: git apply fails silently when on the wrong directory

[Jeff King]

On Tue, Sep 26, 2017 at 05:53:55PM -0700, Ernesto Alfonso wrote:

> I recently ran into a similar issue as described here:
> 
> https://stackoverflow.com/questions/24821431/git-apply-patch-fails-silently-no-errors-but-nothing-happens
> 
> I was using the alias:
> 
> alias ganw='git diff -U0 -w --no-color "$@" | git apply --cached --ignore-whitespace --unidiff-zero -'
> 
> to stage non-whitespace changes, but I was not in the root directory and
> the changes were not being applied. I broke down the command to discover
> the 'git apply' part of the pipe was silently failing to apply anything,
> exiting 0 without even a warning.
> 
> The exit status and lack of warning is terribly misleading, I imagine
> this would be the cause of subtle bugs in automated scripts. 
> 
> Is this expected behaviour?

Yes, this is as documented in git-apply(1):

   Reads the supplied diff output (i.e. "a patch") and applies it to
   files. When running from a subdirectory in a repository, patched
   paths outside the directory are ignored.

I agree it's a potential source of confusion. There's some previous
discussion in this thread:

  https://public-inbox.org/git/CA+DCAeQQQH59Lb43Y4Bi1xktPNoODV11KkUBbKNG1OZ7mDb-UQ@mail.gmail.com/

-Peff