Re: Re: [COMMITTERS] pgsql: Fix mapping of PostgreSQL encodings to Python encodings.

On 06/07/12 10:05, Heikki Linnakangas wrote:
> On 06.07.2012 00:54, Jan Urbański wrote:
>> On 05/07/12 23:30, Peter Eisentraut wrote:
>>> On tor, 2012-07-05 at 22:53 +0200, Jan Urbański wrote:
>>>> The problem is that PLyUnicode_Bytes is (via an ifdef) used as
>>>> PyString_ToString on Python3, which means that there are numerous call
>>>> sites and new ones might appear in any moment. I'm not that keen on
>>>> invoking the traceback machinery on low-level encoding errors.
>>>
>>> Why not?
>>
>> Because it can lead to recursion errors, like the one this patch was
>> supposed to fix. The traceback machinery calls into the encoding
>> functions, because it converts Python strings (like function names) into
>> C strings.
>
> In the backend elog routines, there is a global variable
> 'recursion_depth', which is incremented when an error-handling routine
> is entered, and decremented afterwards. Can we use a similar mechinism
> in PLy_elog() to detect and stop recursion?

I guess we can, I'll try to do some tests in order to see if there's an
easy user-triggereable way of causing PLy_elog to recurse and if not
then a guard like this should be enough as a safety measure against as
yet unknown conditions (as opposed to something we expect to happen
regularly).

Cheers,
Jan