Re: [PATCH] Allow git-diff exit with codes similar to diff(1)

From: Junio C Hamano <junkio@cox.net>
Date: Mar 14, 2007, 16:14 UTC
Message-ID: <7v1wjrby4w.fsf@assigned-by-dhcp.cox.net>
In-Reply-To: <81b0412b0703140701h60982fddw3ed8fa71288cb220@mail.gmail.com>

"Alex Riesen" <raa.lkml@gmail.com> writes:

Show 7 quoted lines

>> To implement --quick correctly, you need to know when it is safe
>> to leave early.  Presence of -S (pickaxe) would most likely mean
>> you shouldn't leave early.
>
> Thanks, that got me thinking. Moved all exit code evaluation
> into diffcore_std, added a field for the code to diff_options,
> and use it if called with --exit-code.

Certainly --quick would be "interesting" and useful to add on top of your patch.

Show 20 quoted lines

> diff --git a/builtin-diff-files.c b/builtin-diff-files.c
> index aec8338..2525ae6 100644
> --- a/builtin-diff-files.c
> +++ b/builtin-diff-files.c
> @@ -17,6 +17,7 @@ int cmd_diff_files(int argc, const char **argv, const char *prefix)
>  {
>  	struct rev_info rev;
>  	int nongit = 0;
> +	int result;
>  
>  	prefix = setup_git_directory_gently(&nongit);
>  	init_revisions(&rev, prefix);
> @@ -29,5 +30,6 @@ int cmd_diff_files(int argc, const char **argv, const char *prefix)
>  		argc = setup_revisions(argc, argv, &rev, NULL);
>  	if (!rev.diffopt.output_format)
>  		rev.diffopt.output_format = DIFF_FORMAT_RAW;
> -	return run_diff_files_cmd(&rev, argc, argv);
> +	result = run_diff_files_cmd(&rev, argc, argv);
> +	return rev.diffopt.diff_exit_code ? rev.diffopt.exit_code: result;
>  }

Yuck. Let's call the former "exit_with_status" (meaning, the caller instructed us to do that) and the latter "has_changes".

Show 6 quoted lines

> +test_expect_failure 'git diff-index --cached HEAD^' '
> +	echo text >>b &&
> +	echo 3 >c &&
> +	git add . &&
> +	git diff-index --exit-code --cached HEAD^
> +'

Please:

        test_expect_success '...
                echo ... &&
                git add . &&
                ! git diff-index ...
        '

I recall somebody on the list had a buggy shell that cannot handle "a && ! b" and tweaked a few tests to work around it. In that case...

	echo ... &&
        git add . &&
	{
        	git diff-index ...; test $? != 0
	}

> +test_expect_failure 'git diff-files' '
> +	echo 3 >>c &&
> +	git diff-files --exit-code
> +'

Likewise

> +git update-index c || error "update-index failed"

Please do not have command outside test_expect without good reason.