[Python-Dev] Difference in RE between 3.2 and 3.3 (or Aaron Swartz memorial)

[Amaury Forgeot d'Arc]

Hi,

2013/3/6 Matěj Cepl <mcepl at redhat.com>

>
> On 2013-02-26, 16:25 GMT, Terry Reedy wrote:
> > On 2/21/2013 4:22 PM, Matej Cepl wrote:
> >> as my method to commemorate Aaron Swartz, I have decided to port his
> >> html2text to work fully with the latest python 3.3. After some time
> >> dealing with various bugs, I have now in my repo
> >> https://github.com/mcepl/html2text (branch python3) working solution
> >> which works all the way to python 3.2 (inclusive;
> >> https://travis-ci.org/mcepl/html2text). However, the last problem
> >> remains. This
> >>
> >> <li>Run this command:
> >> <pre>ls -l *.html</pre></li>
> >> <li>?</li>
> >>
> >> should lead to
> >>
> >>    * Run this command:
> >>
> >>          ls -l *.html
> >>
> >>    * ?
> >>
> >> but it doesn’t. It leads to this (with python 3.3 only)
> >>
> >>      * Run this command:
> >>            ls -l *.html
> >>
> >>      * ?
> >>
> >> Does anybody know about something which changed in modules re or
> >> http://docs.python.org/3.3/whatsnew/changelog.html between 3.2 and
> >> 3.3, which could influence this script?
> >
> > Search the changelob or 3.3 misc/News for items affecting those two
> > modules. There are at least 4.
> > http://docs.python.org/3.3/whatsnew/changelog.html
> >
> > It is faintly possible that the switch from narrow/wide builds to
> > unified builds somehow affected that. Have you tested with 2.7/3.2 on
> > both narrow and wide unicode builds?
>
> So, in the end, I have went the long way and bisected cpython to
> find the commit which broke my tests, and it seems that the
> culprit is http://hg.python.org/cpython/rev/123f2dc08b3e so it is
> clearly something Unicode related.
>
> Unfortunately, it really doesn't tell me what exactly is broken
> (is it a known regression) and if there is known workaround.
> Could anybody suggest a way how to find bugs on
> http://bugs.python.org related to some particular commit (plain
> search for 123f2dc0 didn’t find anything).
>

I strongly suspect an incorrect usage of the "is" operator:
https://github.com/mcepl/html2text/blob/master/html2text.py#L95
Identity of strings is not guaranteed...

Does it change something if you use "==" instead?

-- 
Amaury Forgeot d'Arc
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