Le mercredi 29 septembre 2010 13:45:15, vous avez écrit :
> Marc-Andre Lemburg <mal@egenix.com> added the comment:
> 
> STINNER Victor wrote:
> > STINNER Victor <victor.stinner@haypocalc.com> added the comment:
> > 
> > Forget my previous message, I forgot important points.
> > 
> >> So the only reason why you have to go through
> >> all those hoops is to
> >> 
> >> * allow the complete set of Python supported encoding
> >> 
> >>   names for the PYTHONFSENCODING
> >> 
> >> * make sure that the Py_FilesystemDefaultEncoding is set
> >> 
> >>   to the actual name of the codec as used by the system
> > 
> > Not only. As I wrote in my first message (msg114191), there are two
> > 
> > other good reasons to keep the current code but redecode filenames:
> >  * Encoding aliases: locale encoding is not always written as the
> >  
> >    official Python encoding name. Eg. utf8 vs UTF-8, iso8859-1 vs
> >    latin_1, etc. We have to be able to load Lib/encodings/aliases.py to
> >    to get the Python codec.
> >  
> >  * Codecs implemented in Python: only ascii, latin1, utf8 and mbcs
> >  
> >    codecs are builtin. All other encodings are implemented in Python. If
> >    your filesystem encoding is ShiftJIS, you have to load
> >    Lib/encodings/shift_jis.py to load the codec.
> > 
> > For these two reasons, we have to import Python modules before being
> > able to set the filesystem encoding. So we have to redecode filenames
> > after setting the filesystem encodings.
> 
> No, that's not needed ! Please see my earlier message: you can still
> do all this at a later time during startup and double-check that
> the encoding is indeed valid.

I don't understand how. Eg. if you set Py_FileSystemDefaultEncoding to 
"cp1252" before loading the first module, import a module will have to load the 
codec. Load the codec require to import a module. But how can you open cp1252 
module since you are unable to encode paths to the filesystem encoding (because 
the cp1252 codec is not available yet)?

> If the decoding fails during startup due to a wrong encoding of
> file or path names, ...

It is not not problem described in my previous message. How do you load non-
builtin codecs?

Can you write a patch implementing your ideas? I tried to write such patch 
(set Py_FileSystemDefaultEncoding before loading the first module), but it 
doesn't work for different reasons (all described in this issue). Maybe I 
misunderstood your proposition.