memory leak in reportlab xmllib.FastXMLParser

Hi

I’m not sure if this is the right list for a bug report, any pointers to another address are welcome.

Problem description
===============

The following program creates a memory leak. 

As a result, using reportlab.platypus.paraparser.ParaParser creates a memory leak too.
As a result, wordaxe has a memory leak (my original problem)


# show memory leak
import  gc
from reportlab.lib import  xmllib

assert xmllib.sgmlop # check that we are using FastXMLParser

while True:
   parser = xmllib.XMLParser(verbose=0)
   parser.close()
   gc.collect()


How to reproduce
==============

Just start this program and watch the memory going up … see the 6th column in the ps output below

$ while sleep 10 ; do ps auxww | grep python | grep -v grep ; done
mirko            1023 100,0  0,3  2467680  25608 s000  R+    5:10pm   1:00.44 python t.py
mirko            1023 100,0  0,3  2469728  27424 s000  R+    5:10pm   1:10.47 python t.py
mirko            1023  99,3  0,3  2471520  29048 s000  R+    5:10pm   1:20.50 python t.py
mirko            1023 100,0  0,4  2472288  30616 s000  R+    5:10pm   1:30.54 python t.py


I tested this with reportlab-2.5 and reportlab-2.7 on CentOS-6-64bit and MacOS 10.8 with Python 2.7 and Python 2.6

Analysis
=======

It seems that there is a cyclic reference between FastXMLParser and sgmlop and parser.close() is not cleaning up.

Using the SlowXMLParser instead of XMLParser is working fine.