Incorrect encode in allmydata.testing.web._FakeTahoeUriHandler.render_GET

[exarkun]

render_GET does:

        for arg, value in uri.query:
            if arg == u"uri":
                capability = value
        # it's legal to use the form "/uri/<capability>"                                                                                                                          
        if capability is None and request.postpath and request.postpath[0]:
            capability = request.postpath[0]

        # if we don't yet have a capability, that's an error                                                                                                                      
        if capability is None:
            request.setResponseCode(http.BAD_REQUEST)
            return b"GET /uri requires uri="

        # the user gave us a capability; if our Grid doesn't have any                                                                                                             
        # data for it, that's an error.                                                                                                                                           
        capability = capability.encode('ascii')

So it reads capability from either a DecodedURL's query attribute or from request.postpath[0]. DecodedURL.query is certainly a str.

request.postpath comes from twisted.web.server.Request.process:

    self.postpath = list(map(unquote, self.path[1:].split(b'/')))

self.path must be bytes since it is being split with bytes but it comes from twisted.web.http.Request.requestReceived:

        x = self.uri.split(b'?', 1)

        if len(x) == 1:
            self.path = self.uri
        else:
            self.path, argstring = x
            self.args = parse_qs(argstring, 1)

requestReceived also documents path as bytes and then derives self.uri from it so ... probably bytes.

Thus, in Tahoe, capability is either str or bytes depending on which codepath finds it. And if it is bytes then .encode('ascii') fails.

which seems to confirm that it is bytes.

[exarkun]

​https://github.com/tahoe-lafs/tahoe-lafs/pull/1233

[exarkun]

Fixed in daecfc63b9d39b99b501a769202b4db4b6c2947c