POST application/json error handling with newer WebOb

[dread]

WebOb? from v1.0.7 has some interesting new behaviour with reading request data for different Content-Types:

• It seems that looking at request.body mangles request.POST. See fix in ckan cset:e83bad9caa1b (problem with WebOb? v1.0.7 but may go back to v1.0.4?)

• A particular request caused an AssertionError? during looking at request.body, so we need to enclose this in a try/except. I couldn't recreate it in a test unfortunately (problem with WebOb? v1.0.7 but may go back to v1.0.2?)

Example:

Module ckan.controllers.api:206 in create
<<          log.debug('create: %s' % (context))
               try:
                   request_data = self._get_request_data()
               except ValueError, inst:
                   response.status_int = 400
>>  request_data = self._get_request_data()
Module ckan.lib.base:149 in _get_request_data
<<          cls.log.debug('Retrieving request params: %r' % request.params)
               cls.log.debug('Retrieving request POST: %r' % request.POST)
               cls.log.debug('Retrieving request POST body: %r' % request.body)
               if request.POST:
                   try:
>>  cls.log.debug('Retrieving request POST body: %r' % request.body)
Module paste.registry:137 in __getattr__
<<      
           def __getattr__(self, attr):
               return getattr(self._current_obj(), attr)
           
           def __setattr__(self, attr, value):
>>  return getattr(self._current_obj(), attr)
Module webob.request:470 in _body__get
<<          Return the content of the request body.
               """
               self.make_body_seekable() # we need this to have content_length
               r = self.body_file.read(self.content_length)
               self.body_file.seek(0)
>>  self.make_body_seekable() # we need this to have content_length
Module webob.request:697 in make_body_seekable
<<              self.body_file_raw.seek(0)
               else:
                   self.copy_body()
>>  self.copy_body()
Module webob.request:714 in copy_body
<<                  self.body = self.body_file_raw.read(length)
               elif self.is_body_readable:
                   self.body = self.body_file_raw.read()
                   self._copy_body_tempfile()
               else:
>>  self.body = self.body_file_raw.read()
Module webob.request:1190 in read
<<      def read(self, size=-1):
               body = self._get_body()
               if size < 0:
                   v = body[self.position:]
>>  body = self._get_body()
Module webob.request:1207 in _get_body
<<                  self._body = _encode_multipart(self.vars, self.content_type)
                   else:
                       assert 0, ('Bad content type: %r' % self.content_type)
               return self._body
>>  assert 0, ('Bad content type: %r' % self.content_type)
AssertionError: Bad content type: '; charset=utf-8'