[New-bugs-announce] [issue31758] various refleaks in _elementtree

[Oren Milman]

New submission from Oren Milman <orenmn at gmail.com>:

The following code results in refleaks:
import sys
import _elementtree
builder = _elementtree.TreeBuilder()
parser = _elementtree.XMLParser(target=builder)

refcount_before = sys.gettotalrefcount()
parser.__init__(target=builder)
print(sys.gettotalrefcount() - refcount_before)  # should be close to 0

This is because _elementtree_XMLParser___init___impl()
(in Modules/_elementtree.c) doesn't decref before assigning to fields of
`self`.


The following code also results in refleaks:
import sys
import _elementtree
elem = _elementtree.Element(42)
elem.__setstate__({'tag': 42, '_children': list(range(1000))})

refcount_before = sys.gettotalrefcount()
elem.__setstate__({'tag': 42, '_children': []})
print(sys.gettotalrefcount() - refcount_before)  # should be close to -1000

This is because element_setstate_from_attributes() doesn't decref the old
children before storing the new children.


I would open a PR to fix this soon.

----------
components: XML
messages: 304145
nosy: Oren Milman
priority: normal
severity: normal
status: open
title: various refleaks in _elementtree
type: resource usage
versions: Python 3.7

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Python tracker <report at bugs.python.org>
<https://bugs.python.org/issue31758>
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