ikiwiki/doc/bugs/pythonproxy-utf8_again.mdwn

[[!template  id=gitbranch branch=chrysn/more-proxy-utf8-fail author="[[chrysn]]"]]
[[!template id=gitbranch author="[[chrysn]], [[smcv]]" branch=smcv/ready/more-proxy-utf8-fail
  browse=http://git.pseudorandom.co.uk/smcv/ikiwiki.git/shortlog/refs/heads/ready/more-proxy-utf8-fail]]

the recently introduced fixes for [[crashes in the python proxy even if disabled]]
caused the typical python2 implicit conversion failures ("'ascii' codec
can't...") on my debian sid system -- to fix it, i had to revert commit 154c4ea9e.

i did not dig down all the way to the xml / xmlrpc modules, but my impression
is that some module changed its behavior between stable and sid and now
generates `unicode` strings instead of `str`.

a [[patch]] to allow both versions by inspecting the types and en-/decoding on
demand should work both for anarcat's and my case. i did not test the python3
version, but i'm pretty sure it was already broken after the abovementioned
patch.

-- [[chrysn]]

> update 2014-06-29: the problem persists, but i found it is not trivial to
> reproduce. to demonstrate, use this test plugin:
>
>     #!/usr/bin/env python
>     # -*- coding: utf-8 -*-
>     
>     from proxy import IkiWikiProcedureProxy
>     
>     def preprocess(self, proxy, *args):
>         return repr(self.rpc('pagetype', 'schön'))
>     
>     proxy = IkiWikiProcedureProxy(__name__)
>     proxy.hook('preprocess', preprocess, id='testdirective')
>     proxy.run()
>
> note that when the 'schön' is stored in a variable, the exception changes --
> it seems to me that the issue is related to the way exceptions are encoded.
>
> the suggested patch still applies and solves the issue. --[[chrysn]]

>> In this patch band:
>>
>>     -        xml = _IkiWikiExtPluginXMLRPCHandler._read(in_fd).decode('utf8')
>>     +        response = _IkiWikiExtPluginXMLRPCHandler._read(in_fd)
>>     +        if isinstance(response, unicode):
>>     +            xml = response.encode('utf8')
>>
>> I think you mean `response.decode`, not `response.encode`.
>>
>> Other than that it looks good to me. I like the use of `repr` in debug
>> messages. --[[smcv]]

>>> afaict, encode is fine there -- the relevant methods in python2 are
>>> `unicode.encode` which gives a `str`, and `str.decode` which usually gives
>>> a `unicode`. (i'd happily ditch python2 and port all plugins to python3,
>>> where this is all easier, but my [[todo/vCard rendering]] still uses an
>>> ancient module.) --[[chrysn]]

>>>> You were right about this, `encode` is appropriate to go from `unicode`
>>>> to `str` under Python 2. However, Python 3 is still broken.
>>>>
>>>> My `ready/more-proxy-utf8-fail` branch, based on yours,
>>>> [[fixes the `rst` test when run under Python 3|bugs/rst_plugin_hangs_when_used_with_Python_3]]
>>>> and hopefully also fixes this one. Please check that it still
>>>> fixes your test-case too.
>>>>
>>>> Joey, I think this is [[ready for merge|users/smcv/ready]] even if it
>>>> doesn't fix chrysn's bug - it does fix Python 3 support
>>>> in general. --[[smcv]]

>>>>> [[merged|done]] --[[smcv]]