From: Jacob Keller <jacob.keller@gmail.com>
Date: Wed, 30 Mar 2016 19:14:26 GMT
Subject: Re: weird diff output?
Message-ID: <CA+P7+xp+oT2zMBZqR8zvXKm8Zp5btaNyoOWFTts29HMwX+2o=Q@mail.gmail.com>
In-Reply-To: <CA+P7+xqskf6Ti3tVwMrOAaj3EDykRLKiXG5EbbzkjRsZP0s_7w@mail.gmail.com>

On Tue, Mar 29, 2016 at 11:05 PM, Jacob Keller <jacob.keller@gmail.com> wrote:
> On Tue, Mar 29, 2016 at 9:55 PM, Jeff King <peff@peff.net> wrote:
>> One thing I like to do when playing with new diff ideas is to pipe all
>> of "log -p" for a real project through it and see what differences it
>> produces.
>>
>
> Great idea!
>
>> Below is a perl script that implements Stefan's heuristic. I checked its
>> output on git.git with:
>>
>>   git log --format='commit %H' -p >old
>>   perl /path/to/script <old >new
>>   diff -F ^commit -u old new | less
>>
>> which shows the differences, with the commit id in the hunk header
>> (which makes it easy to "git show $commit | perl /path/to/script" to
>> see the new diff with more context.
>>
>
> I'll try to run this  against my projects and see what it looks like
> to see if I can spot (m)any counter examples, which would indicate
> it's a bad idea. I may have some time in the next few days to see how
> hard it would be to fully integrate it into the diff machinery too.
>
> Thanks for the help!
>
> Regards,
> Jake
>

I ran this on a few of my local projects and it doesn't seem to
produce any false positives so far. Everything looks good. Of course
this is with just traditional C code. I am currently trying to run
this against the history of Linux as well and see if I can find
anything that seems bad there.

Thanks,
Jake