Message 295150 - Python tracker

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In-reply-to
Author	Daniel Lepage
Recipients	Daniel Lepage
Date	2017年06月05日.00:25:15
SpamBayes Score	-1.0
Marked as misclassified	Yes
Message-id	<1496622334.44.0.71686890535.issue30570@psf.upfronthosting.co.za>

Content
The following code causes a segmentation fault: class Failure(object): def __getattr__(self, attr): return (self, None) issubclass(Failure(), int) I am running a macbook pro, OS X 10.12.4, and have observed the problem in python 3.5.2, 3.6.0, and 3.6.1. It appears that returning (self,) causes it to go into an infinite loop attempting to get `x.__bases__`, and returning `(self, y)` for any value `y` causes it to attempt to get `x.__bases__` 262,030 times and then segfault. A crash log is attached.

Content

The following code causes a segmentation fault:
class Failure(object):
 def __getattr__(self, attr):
 return (self, None)
issubclass(Failure(), int)
I am running a macbook pro, OS X 10.12.4, and have observed the problem in python 3.5.2, 3.6.0, and 3.6.1.
It appears that returning (self,) causes it to go into an infinite loop attempting to get `x.__bases__`, and returning `(self, y)` for any value `y` causes it to attempt to get `x.__bases__` 262,030 times and then segfault.
A crash log is attached.

History
Date	User	Action	Args
2017年06月05日 00:25:34	Daniel Lepage	set	recipients: + Daniel Lepage
2017年06月05日 00:25:34	Daniel Lepage	set	messageid: <1496622334.44.0.71686890535.issue30570@psf.upfronthosting.co.za>
2017年06月05日 00:25:34	Daniel Lepage	link	issue30570 messages
2017年06月05日 00:25:33	Daniel Lepage	create

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