[ python-Bugs-416288 ] infrequent memory leak in pyexpat

Wed Apr 12 17:00:23 CEST 2006

Bugs item #416288, was opened at 2001-04-15 17:35
Message generated for change (Comment added) made by gbrandl
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Category: XML
Group: None
>Status: Closed
>Resolution: Fixed
Priority: 2
Submitted By: douglas orr (dougbo)
Assigned to: Nobody/Anonymous (nobody)
Summary: infrequent memory leak in pyexpat

Initial Comment:
In pyexpat.c, the macro call for the handler dispatch 
(my##NAME##Handler) for CharacterHandler allocates an 
object implicitly by calling one of the conversion-to-
unicode routines.  

If there is a problem in the PyBuildValue, resulting 
in args == NULL, that object will be leaked.

Low priority, but the macros probably need some 
reworking to handle this.

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>Comment By: Georg Brandl (gbrandl)
Date: 2006-04-12 15:00

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This was fixed in response to bug [ 984722 ] Py_BuildValue
loses reference counts on error, in rev. 36480.

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Comment By: Martin v. LÃ¶wis (loewis)
Date: 2006-04-12 08:01

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I don't think I will do anything about this anytime soon, so
unassigning myself.

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Comment By: Martin v. LÃ¶wis (loewis)
Date: 2002-03-28 23:20

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No, currently, it can only leak: the argument being passed
will have an extra ref count, which supposedly will be
consumed by the tuple. If something fails, some of the N
arguments will have been stored in the
tuple-under-construction, and will be released when the
tuple is released. 'N' arguments not yet consumed will leak.

Processing should continue in case of an error, and DECREF
all N arguments.

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Comment By: Guido van Rossum (gvanrossum)
Date: 2002-03-28 22:34

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Hm, the 'N' format code looks really scary. Can't it end up
DECREF'ing an object too many times if something fails?

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Comment By: Martin v. LÃ¶wis (loewis)
Date: 2001-06-09 11:48

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That seems to be a bug in Py_BuildValue: It should decref 
its N arguments if it can't create a tuple.

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