[PyQt] Py_XDECREF(*sipUnused) Segfault

[Phil Thompson]

On Tue, 08 Jun 2010 17:17:08 +0200, Matteo Bertozzi <th30z at develer.com>
wrote:
> I've a segfault for a NULL pointer access:
>     Py_XDECREF(*sipUnused);
> 
> The code to reproduce segfault is really simple:
> Method code set sipIsError to True and raise PyExc_ValueError.
> 
> ____(sipSimpleWrapper *, PyObject *sipArgs, PyObject *sipKwds, PyObject
> **sipUnused, PyObject **, PyObject **sipParseErr)
> 
> sipUnused seems to be NULL, and Py_XDECREF(*sipUnused)
> try to access to address 0... and the result is a segfault.
> 
> A very simple workaround can be check sipUnused before call Py_XDECREF.
> 
>> --- sip/sipgen/gencode.c	(revision 29039)
>> +++ sip/sipgen/gencode.c	(working copy)
>> @@ -10294,7 +10294,7 @@
>>  
>>          prcode(fp,
>>  "\n"
>> -"            Py_XDECREF(*sipUnused);\n"
>> +"            if (sipUnused != NULL) Py_XDECREF(*sipUnused);\n"
>>  "            sipAddException(sipError, sipParseErr);\n"
>>  "\n"
>>  "            if (sipError == sipErrorFail)\n"
>> @@ -10308,7 +10308,7 @@
>>              prcode(fp,
>>  "            if (sipIsErr)\n"
>>  "            {\n"
>> -"                Py_XDECREF(*sipUnused);\n"
>> +"                if (sipUnused != NULL) Py_XDECREF(*sipUnused);\n"
>>  "                sipAddException(sipErrorFail, sipParseErr);\n"
>>  "                return NULL;\n"
>>  "            }\n"
> 
> Thanks.

Should be fixed in tonight's snapshot - thanks.

Phil