[ZCM] [ZC] 1777/ 6 Comment "ExtensionClass delattr raises KeyError"

[Collector: Zope Bugs, Features, and Patches ...]

Issue #1777 Update (Comment) "ExtensionClass delattr raises KeyError"
 Status Accepted, Zope/bug low
To followup, visit:
  http://www.zope.org/Collectors/Zope/1777

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= Comment - Entry #6 by tseaver on May 12, 2005 11:12 am

The issue appears to disappear in 2.8, because ExtensionClass loses
lots of its special behavior::

 [/home/tseaver/projects/Zope-CVS/Zope-SVN-trunk/instance]
 $ bin/zopectl run collector_1777.py
 Traceback (most recent call last):
   File "collector_1777.py", line 11, in ?
     del foo.nonesuch
 AttributeError: 'Foo' object has no attribute 'nonesuch'
 Traceback (most recent call last):
   File "collector_1777.py", line 21, in ?
     del bar.nonesuch
 AttributeError: 'Bar' object has no attribute 'nonesuch'

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= Comment - Entry #5 by tseaver on May 12, 2005 8:13 am


Uploaded:  "collector_1777-no_help.patch"
 - http://www.zope.org/Collectors/Zope/1777/collector_1777-no_help.patch/view
Attaching a patch to ExtensionClass.c which *does not* fix the
problem, although it does attempt to address all cases where
'PyDict_DelItem' and 'PyDict_DelItemString' are called.

Beats the heck out of me how I can still be getting KeyErrors,
but I do.
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= Comment - Entry #4 by tseaver on May 12, 2005 8:06 am


Uploaded:  "collector_1777.py"
 - http://www.zope.org/Collectors/Zope/1777/collector_1777.py/view
Attaching a script which shows the bug against ExtensionClass.Base,
too.
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= Assign - Entry #3 by tseaver on May 11, 2005 6:35 pm

 Supporters added: jim; removed: tim_one


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= Comment - Entry #2 by tim_one on May 11, 2005 5:31 pm

The chance that I can make time to look at this in ZODB 3.2 is approximately 0%.

ExtensionClass isn't part of ZODB 3.4, so the chance that I'll look at this in Zope 2.8 is something less than 0% <0.4 wink>.
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= Request - Entry #1 by tseaver on May 11, 2005 4:58 pm

 Status: Pending => Accepted

 Supporters added: tim_one

The two setattr implementations in ExtensionClass.c
('subclass_simple_setattro' and 'subclass_simple_setattr')
don't check / convert errors returned by PyDict_DelItem, leading to::

 >>> from Persistence import Persistent
 >>> class Foo(Persistent):
 ...     pass
 ...
 >>> foo = Foo()
 >>> del foo.nonesuch
 Traceback (most recent call last):
   File "<stdin>", line 1, in ?
 KeyError: 'nonesuch'


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