Re: segfault for git log --graph --no-walk --grep a

> On Mon, Feb 11, 2013 at 12:36:52PM -0800, Junio C Hamano wrote:
>
>> Junio C Hamano <gitster@pobox.com> writes:
>> 
>> > Jeff King <peff@peff.net> writes:
>> >
>> >> On Fri, Feb 08, 2013 at 04:47:01PM -0800, Junio C Hamano wrote:
>> >>
>> >>> > Yeah, that actually is a good point.  We should be using logmsg_reencode
>> >>> > so that we look for strings in the user's encoding.
>> >>> 
>> >>> Perhaps like this.  Just like the previous one (which should be
>> >>> discarded), this makes the function always use the temporary strbuf,
>> >>> so doing this upfront actually loses more code than it adds ;-)
>> >>
>> >> I didn't see this in What's Cooking or pu. We should probably pick an
>> >> approach and go with it.
>> >>
>> >> I think using logmsg_reencode makes sense. I'd be in favor of avoiding
>> >> the extra copy in the common case, so something like the patch below. If
>> >> you feel strongly about the code cleanup at the minor run-time expense,
>> >> I won't argue too much, though.
>> >
>> > Sounds good to me.  Care to do the log message while at it?
>> 
>> Heh, how about this?  I still need a sign-off from you.
>
> I'm working on the log message and tests right now. There's also a minor
> code fixup needed to compile with -Wall.

>
>>     log --grep: look for the given string in log output encoding
>>     
>>     We used to grep in the raw commit buffer contents, possibly pieces
>>     of notes encoded in log output encoding appended to it, which was
>>     insane.
>>     
>>     Convert the contents of the commit message also to log output
>>     encoding before looking for the string.  This incidentally fixes a
>>     possible NULL dereference that can happen when commit->buffer has
>>     already been freed, which can happen with
>>     
>>     	git commit -m 'text1' --allow-empty
>>     	git commit -m 'text2' --allow-empty
>>     	git log --graph --no-walk --grep 'text2'
>>     
>>     which arguably does not make any sense (--graph inherently wants a
>>     connected history, and by --no-walk the command line is telling us
>>     to show discrete points in history without connectivity), and we
>>     probably should forbid the combination, but that is a separate
>>     issue.
>
> I'll use bits of that. I had sort of punted on the "how to reproduce the
> segfault" issue entirely because you had noted that it was not a sane
> thing to do. Still, I think it makes sense to mention it with the caveat
> you give here.
>
> -Peff