From: Jakob Pfender <jpfender@elegosoft.com>
Date: Thu, 17 Mar 2011 11:15:07 GMT
Subject: Re: [PATCH] diff --quiet: disable optimization when --diff-filter=X is used
Message-ID: <4D81ED3B.3000500@elegosoft.com>
In-Reply-To: <7vmxku64sh.fsf_-_@alter.siamese.dyndns.org>



On 03/17/2011 12:09 AM, Junio C Hamano wrote:
> The code notices that the caller does not want any detail of the changes
> and only wants to know if there is a change or not by specifying --quiet.
> And it breaks out of the loop when it knows it already found any change.
>
> When you have a post-process filter (e.g. --diff-filter), however, the
> path we found to be different in the previous round and set HAS_CHANGES
> bit may end up being uninteresting, and there may be no output at the end.
> The optimization needs to be disabled for such case.
>
> Note that the f245194 (diff: change semantics of "ignore whitespace"
> options, 2009-05-22) already disables this optimization by refraining
> from setting HAS_CHANGES when post-process filters that need to inspect
> the contents of the files (e.g. -S, -w) in diff_change() function.

That fixes it nicely, thank you.

>
> Signed-off-by: Junio C Hamano<gitster@pobox.com>
> ---
>
>   * This time with tests, on top of 90b1994 (diff: Rename QUIET internal
>     option to QUICK, 2009-05-23), which was the last commit in the series
>     that introduced the incorrect optimization in the first place.
>
>     Note that the test script was renamed to t/t4040 in today's codebase,
>     but it merges cleanly.
>
>   diff-lib.c                   |    3 ++-
>   t/t4037-whitespace-status.sh |    7 +++++++
>   2 files changed, 9 insertions(+), 1 deletions(-)
>
> diff --git a/diff-lib.c b/diff-lib.c
> index b7813af..bfa6503 100644
> --- a/diff-lib.c
> +++ b/diff-lib.c
> @@ -74,7 +74,8 @@ int run_diff_files(struct rev_info *revs, unsigned int option)
>   		int changed;
>
>   		if (DIFF_OPT_TST(&revs->diffopt, QUICK)&&
> -			DIFF_OPT_TST(&revs->diffopt, HAS_CHANGES))
> +		    !revs->diffopt.filter&&
> +		    DIFF_OPT_TST(&revs->diffopt, HAS_CHANGES))
>   			break;
>
>   		if (!ce_path_match(ce, revs->prune_data))
> diff --git a/t/t4037-whitespace-status.sh b/t/t4037-whitespace-status.sh
> index a30b03b..abc4934 100755
> --- a/t/t4037-whitespace-status.sh
> +++ b/t/t4037-whitespace-status.sh
> @@ -60,4 +60,11 @@ test_expect_success 'diff-files -b -p --exit-code' '
>   	git diff-files -b -p --exit-code
>   '
>
> +test_expect_success 'diff-files --diff-filter --quiet' '
> +	git reset --hard&&
> +	rm a/d&&
> +	echo x>>b/e&&
> +	test_must_fail git diff-files --diff-filter=M --quiet
> +'
> +
>   test_done