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Re: PATCH Fix malformed utf8 in regexec.c only shows with Test::More

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From:
karl williamson
Date:
December 27, 2008 13:34
Subject:
Re: PATCH Fix malformed utf8 in regexec.c only shows with Test::More
Message ID:
49569F63.90309@khwilliamson.com
demerphq wrote:
> 2008/12/27 karl williamson <public@khwilliamson.com>:
>> Rafael Garcia-Suarez wrote:
>>> 2008/12/26 karl williamson <public@khwilliamson.com>:
>>>> Attached is a patch for this.  The problem is that in this subroutine p
>>>> may
>>>>  or may not be in utf8, and the flag do_utf8 indicates which.  The code
>>>> calls  various functions passing both p and do_utf8, and these work.  But
>>>> to_utf8_fold() expects its argument to always be in utf8, and this caused
>>>> the problem  Also the av's are stored as utf8, so the memEQ would not
>>>> work
>>>> correctly on a non-utf8 p even though no error message would be
>>>> generated.
>>>>
>>>> The patch creates a copy of p in utf8, if necessary, and uses that even
>>>> when
>>>> calling the functions that accept the do_utf8 flag, as they create
>>>> temporaries, convert to utf8, and then throw the conversion away.  It is
>>>> more efficient to do the conversion once in the caller and pass that to
>>>> each
>>>> routine.
>>>>
>>>> I'm not sure what to do about a test case.
>>>>
>>>> "\xc0" =~ qr/[\x{1f4}\xc0]/;
>>>>
>>>> doesn't show the problem, but
>>>>
>>>> use Test::More tests => 1;
>>>> like("\xc0", qr/[\x{1f4}\xc0]/i, 'get malformed utf8');
>>>>
>>>> does.  And it looks like none of the existing re tests use Test.
>>> Then there is probably a problem in Test::More itself ?
>>>
>>> (Is there a bug number for this?)
>>>
>>> I've tested the patch, but I would feel more comfortable with a test
>>> case. (or with a comment from Yves)
>>>
>>>
>> No bug number.  Should I create one?
>>
>> I suspect that it isn't a bug in Test::More, but that it calls things
>> somehow differently, which is kind of scary in itself that it perturbs the
>> environment  Maybe a certain class of tests shouldn't be done using Test.  I
>> don't know.
>>
>> If we don't hear from Yves in the meantime, I'll look tomorrow to see how to
>> reproduce it without using Test.
> 
> Is this a problem with casefolding unicode characters in a charclass?
> 
> I have to admit that on reading this I dont have much to add. And my
> windows box is offline these days due to a hardware failure so if im
> going to debug it ill have to learn gdb finally. Which could take a
> while :-)
> 
> Yves
> 
> 
> 
> 
This is turning into several threads.  I'll separate out the casefolding 
charclass into a separate one.

Duh! The reason I didn't get a malformed message without Test::More is 
because I forgot to turn on warnings.

Attached is another patch, to add a test case.

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