Re: git apply fails silently when on the wrong directory

From: Jeff King <peff@peff.net>
Date: Sep 27, 2017, 01:25 UTC
Message-ID: <20170927012506.5tplhzain5z4eyxy@sigill.intra.peff.net>
In-Reply-To: <87k20lt10c.fsf@gmail.com>

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

Show 17 quoted lines

> 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