[New-bugs-announce] [issue20542] Assertion failure in test_readline

[Nick Coghlan]

New submission from Nick Coghlan:

test_readline is consistently failing with an assertion failure in debug builds. I'm going to add a skip for the time being, because I don't know the UnicodeWriter or UTF7 code well enough to guess where the inconsistency may be being introduced.

Relevant extract from faulthandler stack dump:

Current thread 0x00007f83a3e14740 (most recent call first):
  File "/home/ncoghlan/devel/py3k/Lib/codecs.py", line 494 in read
  File "/home/ncoghlan/devel/py3k/Lib/codecs.py", line 548 in readline
  File "/home/ncoghlan/devel/py3k/Lib/test/test_codecs.py", line 168 in test_readline


Relevant extract from gdb trace:

#4  0x00000000004f092f in _PyUnicode_CheckConsistency (
    op='xxx\naaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa', check_content=1)
    at Objects/unicodeobject.c:410
#5  0x0000000000544b75 in _PyUnicodeWriter_Finish (writer=0x7ffffffd7d40) at Objects/unicodeobject.c:13503
#6  0x0000000000510f5b in PyUnicode_DecodeUTF7Stateful (s=0x7fffed18b5b8 "", size=72, 
    errors=0x7ffff19db0e8 "strict", consumed=0x7ffffffd7e48) at Objects/unicodeobject.c:4472
#7  0x0000000000607922 in utf_7_decode (self=<module at remote 0x7ffff197cd58>, 
    args=(b'xxx\naaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa+ICg', 'strict'))
    at ./Modules/_codecsmodule.c:271

----------
assignee: serhiy.storchaka
keywords: 3.4regression, buildbot
messages: 210467
nosy: larry, ncoghlan, serhiy.storchaka
priority: release blocker
severity: normal
stage: needs patch
status: open
title: Assertion failure in test_readline
type: crash
versions: Python 3.4

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Python tracker <report at bugs.python.org>
<http://bugs.python.org/issue20542>
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