From: Philip Oakley <philipoakley@iee.org>
Date: Thu, 08 Aug 2013 21:36:51 GMT
Subject: Re: [PATCH] diff: remove another ternary expression always evaluating to true
Message-ID: <87241414EE67485DAC10602B3BB85F2D@PhilipOakley>
In-Reply-To: <1375988103-29947-1-git-send-email-stefanbeller@googlemail.com>

From: "Stefan Beller" <stefanbeller@googlemail.com>
Sent: Thursday, August 08, 2013 7:55 PM
Subject: [PATCH] diff: remove another ternary expression always 
evaluating to true

Have these issues (and the earlier expression simplifications patches 
$gmane/231916, $gmane/231912 ) been discovered with the "STACK" tool I'd 
noted in $gmane/230542 which you were also interested in (I've not had 
chance to run the tool).

If so, it's probably worth referencing the tool and the paper which 
explains the broader issues.

Philip


> The condition before the changed line dereferences 'one' to query the 
> mode,
> so if the condition evaluates to true, the variable one must not be 
> null.
> Therefore we do not need the ternary operator depending on one, giving
> either one->path or two->path. This always evaluates to one->path, so
> we can remove the ternary operator.
>
> The condition and the usage of the ternary operator have been 
> introduced
> by the same commit (752c0c24, 2009-10-19, Add the --submodule option 
> to
> the diff option family). As that commit message refers to a 
> GitTogether
> I'd assume that patch was crafted in a hurry, so maybe overlooking the
> need for a ternary operator there.
>
> Signed-off-by: Stefan Beller <stefanbeller@googlemail.com>
> ---
> diff.c | 3 +--
> 1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/diff.c b/diff.c
> index 80f8439..f30b7e4 100644
> --- a/diff.c
> +++ b/diff.c
> @@ -2252,8 +2252,7 @@ static void builtin_diff(const char *name_a,
>  (!two->mode || S_ISGITLINK(two->mode))) {
>  const char *del = diff_get_color_opt(o, DIFF_FILE_OLD);
>  const char *add = diff_get_color_opt(o, DIFF_FILE_NEW);
> - show_submodule_summary(o->file, one ? one->path : two->path,
> - line_prefix,
> + show_submodule_summary(o->file, one->path, line_prefix,
>  one->sha1, two->sha1, two->dirty_submodule,
>  meta, del, add, reset);
>  return;
> -- 
> 1.8.4.rc1.25.gd121ba2
>
> --