Unhandled exception during timezone selection

[Robert Schroll]

I was attempting to install 12.04 from the amd64 LiveCD. During the timezone selection, there is an unhandled ValueError if there is a network connection but not an internet connection. In my case, I was sitting behind an AP that requires authentication via a Java applet (which I install from the internet (for which I need Java (which I install from the internet (for which ... [Curse you Cisco!])))). Therefore, the installer could send out a JSON request, but what it gets back is the authentication page, not a valid JSON document. That leads to this error:

Traceback (most recent call last):
  File "/usr/lib/ubiquity/plugins/ubi-timezone.py", line 173, in geoname_cb
    for result in json.loads(message.response_body.data):
  File "/usr/lib/python2.7/json/__init__.py", line 326, in loads
    return _default_decoder.decode(s)
  File "/usr/lib/python2.7/json/decoder.py", line 366, in deocde
    obj, end = self.raw_decode(s, idx=_w(s, 0).end())
  File "/usr/lib/python2.7/json/decoder.py", line 384, in raw_decode
    raise ValueError("No JSON object could be decoded")
  ValueError: No JSON object could be decoded

The installer worked fine once I shut off the network connection, so I think the fix is easy: Put a try/except block around the loop at line 173 of ubi-timezone.py, with "self.geoname_cache[text] = model" as an else clause.

If you need the logs, let me know. But I hope the problem is rather clear.