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Re: [PATCH] t4062: stop using repetition in regex

From
René Scharfe <l.s.r@web.de>
Date
Aug 8, 2017, 22:34 UTC
Message-ID
<cd60d779-fe38-4f0e-4d36-2c40b2afec7d@web.de>
In-Reply-To
<xmqq7eydae7r.fsf@gitster.mtv.corp.google.com>
Am 09.08.2017 um 00:26 schrieb Junio C Hamano:
Show 23 quoted lines
> Junio C Hamano <gitster@pobox.com> writes:
> 
>> So I find Dscho's concern quite valid, even though I do believe you
>> when you say the code somehow segfaults.  I just can not tell
>> how/why it would segfault, though---it is possible that regexec()
>> implementation is stupid and does not realize that it can return early
>> reporting success without looking at the rest of the buffer, but
>> somehow I find it unlikely.
>>
>> Puzzled.
>>
>>> You get different results?  How is that possible?  The search string is
>>> NUL-terminated in each case, while the point of the test is that the
>>> file contents isn't, right?
> 
> Intellectual curiosity tells me we may want to find out why it
> fails, but in the meantime, I think replacing the test with "0$" to
> force the scanner to find either the end of line or the end of the
> buffer may be a good workaround.  We do not have to care how many of
> random bytes are in front of the last "0" in order to ensure that
> the regexec_buf() does not overstep to 4097th byte, while seeing
> that regexec() that does not know how long the haystack is has to do
> so, no?
Our regexec() calls strlen() (see my other reply).
Using "0$" looks like the best option to me.
René
Previous: Junio C HamanoNext: Junio C Hamano
Message 6 of 17 in “t4062: stop using repetition in regex”
  1. t4062: stop using repetition in regexRené Scharfe, Aug 8, 2017
  2. Johannes SchindelinAug 8, 2017
  3. René ScharfeAug 8, 2017
  4. Junio C HamanoAug 8, 2017
  5. Junio C HamanoAug 8, 2017
  6. René ScharfeAug 8, 2017
  7. Junio C HamanoAug 9, 2017
  8. René ScharfeAug 9, 2017
  9. René ScharfeAug 9, 2017
  10. David CoppaAug 9, 2017
  11. Johannes SchindelinAug 9, 2017
  12. Junio C HamanoAug 9, 2017
  13. René ScharfeAug 9, 2017
  14. Junio C HamanoAug 9, 2017
  15. René ScharfeAug 10, 2017
  16. Junio C HamanoAug 11, 2017
  17. René ScharfeAug 8, 2017

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