TextWrap vs words 1-character shorter than the width

[sam]

BPO	1146
Nosy	@birkenfeld
Files	textwrap_r58153.diff textwrap_revised_r58153.diff textwrap_revised_r60075.diff

^{Note: these values reflect the state of the issue at the time it was migrated and might not reflect the current state.}

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GitHub fields:

assignee = 'https://github.com/birkenfeld'
closed_at = <Date 2008-01-19.19:48:42.054>
created_at = <Date 2007-09-11.13:37:37.004>
labels = ['type-bug']
title = 'TextWrap vs words 1-character shorter than the width'
updated_at = <Date 2008-01-19.19:48:42.053>
user = 'https://bugs.python.org/sam'

bugs.python.org fields:

activity = <Date 2008-01-19.19:48:42.053>
actor = 'georg.brandl'
assignee = 'georg.brandl'
closed = True
closed_date = <Date 2008-01-19.19:48:42.054>
closer = 'georg.brandl'
components = []
creation = <Date 2007-09-11.13:37:37.004>
creator = 'sam'
dependencies = []
files = ['8428', '8429', '9216']
hgrepos = []
issue_num = 1146
keywords = ['patch']
message_count = 6.0
messages = ['55822', '55909', '55910', '55911', '60171', '60221']
nosy_count = 3.0
nosy_names = ['georg.brandl', 'sam', 'quentin.gallet-gilles']
pr_nums = []
priority = 'normal'
resolution = 'fixed'
stage = None
status = 'closed'
superseder = None
type = 'behavior'
url = 'https://bugs.python.org/issue1146'
versions = ['Python 2.5']

[sam]

>>> from textwrap import wrap
>>> wrap("foobarbaz reallylongwordgoeshere", width = 10)
['foobarbaz r', 'eallylongw', 'ordgoesher', 'e']
>>> print [len(s) for s in _]
[11, 10, 10, 1]

This only seems to happen when the first word on the line is exactly one
character shorter than the width, and the next word is too long to fit,
so it is broken:

>>> wrap("foo bar reallylongwordgoeshere", width = 7)
['foo bar', 'reallyl', 'ongword', 'goesher', 'e']
>>> wrap("foobarbaz really longwordgoeshere", width = 10)
['foobarbaz', 'really lon', 'gwordgoesh', 'ere']
>>> wrap("foobarbaz reallylongwordgoeshere", width = 10,
break_long_words = False)
['foobarbaz', 'reallylongwordgoeshere']

This is on Python 2.5, on Windows XP SP2.

[quentingallet-gilles]

The bug is present in trunk and has been there since rev 33955. This
revision contained a fix to an infinite loop when indentation was set
longer than width with long word breaking enabled. In that case, it
would strip off at least one character on every pass. The fix was
however a bit too general, leading to the reported bug.

The added patch makes sure this doesn't happen anymore when indentation
isn't involved.

[quentingallet-gilles]

The previous patch is suboptimal and doesn't solve all cases. This one
does. My apologies.

[birkenfeld]

I'll look at this shortly.

[quentingallet-gilles]

As i revisited this one for the Bug Day, I found I could optimize the
patch a little bit. Here's the updated diff.

Also... I think it's a good candidate for 2.5 maintenance release. Any
thoughts ?

[birkenfeld]

Thanks for the patches, committed in r60093!