Re: [COMMITTERS] pgsql: Add traceback information to PL/Python errors

On 08/04/11 00:25, Robert Haas wrote:
> On Thu, Apr 7, 2011 at 5:06 PM, Jan Urbański <wulczer@wulczer.org> wrote:
>> On 07/04/11 23:01, Robert Haas wrote:
>>> On Wed, Apr 6, 2011 at 3:37 PM, Peter Eisentraut <peter_e@gmx.net> wrote:
>>>> Add traceback information to PL/Python errors
>>>>
>>>> This mimics the traceback information the Python interpreter prints
>>>> with exceptions.
>>>>
>>>> Jan Urbański
>>>
>>> On my system this spits out a warning:
>>>
>>> plpython.c: In function ‘PLy_traceback’:
>>> plpython.c:4487: warning: ‘s’ may be used uninitialized in this function
>>> plpython.c:4487: note: ‘s’ was declared here
>>>
>>> That appears to be a live bug, unless it's guaranteed that lineno will
>>> always be > 0.
>>
>> lineno should be > 0, unless Python is trying to tell us that the code
>> frame originates from before the function.
>>
>>> Also, the loop test should really be written as current < lineno,
>>> rather than current != lineno, just in case we should manage to pass a
>>> lineno < 0, which with the current code would go into the tank and
>>> spin.
>>
>> Yeah, good point.
>>
>>> This part looks pretty sketchy, too:
>>>
>>>     while (s && isspace((unsigned char) *s))
>>>         s++;
>>>
>>> Perhaps we meant to test *s here.  It's hard to believe that we're
>>> really intending to test whether the pointer has fallen off the end of
>>> the address space and wrapped around to NULL.
>>
>> Gah, so short a function and so many things that I managed to get wrong.
> 
> Patch?

Attached.

>> There's also this:
>> http://archives.postgresql.org/pgsql-hackers/2011-04/msg00334.php
> 
> Yep.  I am assuming Peter will look at that one.

I guess so. This only fixes the things you noticed.

Jan