Re: git-grep Bus Error

From: Junio C Hamano <gitster@pobox.com>
Date: Mar 9, 2009, 00:29 UTC
Message-ID: <7v1vt7k07o.fsf@gitster.siamese.dyndns.org>
In-Reply-To: <C36B091A-ABE9-4C74-9E59-4EBD50E3B9F5@gernhardtsoftware.com>

Brian Gernhardt <brian@gernhardtsoftware.com> writes:

Show 12 quoted lines

> The --color display code in git-grep is giving me a bus error in
> show_line at line 492:
>
>>                         printf("%.*s%s%.*s%s",
>>                                match.rm_so, bol,
>>                                opt->color_match,
>>                                match.rm_eo - match.rm_so, bol +
>> match.rm_so,
>>                                GIT_COLOR_RESET);
>
> The first problem is that %.*s does not appear to do on OS X what the
> author thinks it does.

Hmm, that means that printf on OSX does not dohat the POSIX thinks it ought to.

    http://www.opengroup.org/onlinepubs/009695399/functions/fprintf.html

says that "a negative precision is taken as if the precision were omitted"; it does not say "a negative or zero" here.

Which is a bit sad, because we would need to apply a workaround like yours. We shouldn't have to.

Show 9 quoted lines

> To fix that, I changed it to the following:
>
>> 			if( match.rm_so > 0 )
>> 				printf( "%.*s", match.rm_so, bol );
>> 			if( match.rm_eo > match.rm_so )
>> 				printf("%s%.*s%s",
>> 					   opt->color_match,
>> 					   match.rm_eo - match.rm_so, bol + match.rm_so,
>> 					   GIT_COLOR_RESET);

> This code does not fail, but instead gives lines like the following
> (showing the raw color codes):
>
> .gitignore:\033[31m\033[1m(nugit

Hmm, that is strange. Your above change issues color_match and COLOR_RESET only when you have something between rm_eo and rm_so. I do not see anything between "ESC [ 31 m" and "ESC [ m" above, and you have an extra "1" between "ESC [" and terminating "m" in the reset sequence.