[issue24696] Don't use None as sentinel for traceback

[Benjamin Peterson]

Benjamin Peterson  added the comment:

3.4 is out of bugfix support.

--
nosy: +benjamin.peterson
resolution:  -> out of date
stage:  -> resolved
status: open -> closed

___
Python tracker 

___
___
Python-bugs-list mailing list
Unsubscribe: 
https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com

[issue24696] Don't use None as sentinel for traceback

[Adam Bartoš]

New submission from Adam Bartoš:

There is a subtle bug in Python 3.4 implementation of traceback library:

 import traceback

 try:
... 1 / 0
... except Exception as e:
... exc = e
...
 traceback.print_exception(exc.__class__, exc, exc.__traceback__)
Traceback (most recent call last):
  File stdin, line 2, in module
ZeroDivisionError: division by zero
 
 traceback.print_exception(exc.__class__, exc, None)
Traceback (most recent call last):
  File stdin, line 2, in module
ZeroDivisionError: division by zero
 
 traceback.print_exception(exc.__class__, exc, None, chain=False)
ZeroDivisionError: division by zero

As can be seen, giving None traceback is ignored if chain == True. This is 
because None is incorrectly used as a sentinel value in traceback._iter_chain 
(see line 135).

Note that this bug is fixed in Python 3.5 since there is a new implementation 
of traceback module using TracebackException objects. Will this be backported 
to Python 3.4? Otherwise, the bug itself should be fixed anyway.

--
components: Library (Lib)
messages: 247210
nosy: Drekin
priority: normal
severity: normal
status: open
title: Don't use None as sentinel for traceback
type: behavior
versions: Python 3.4

___
Python tracker rep...@bugs.python.org
http://bugs.python.org/issue24696
___
___
Python-bugs-list mailing list
Unsubscribe: 
https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com