praekelt/vumi — pull request #775 by smn (2014-04-16 04:18:43+00:00)
Title: WeChat unsubscribe events not being handled properly

```
2014-04-16 04:09:52+0000 [-] gh_00780d74d04e
2014-04-16 04:09:52+0000 [-] owsArtykOMo-7uebocxkM_xGXgsU
2014-04-16 04:09:52+0000 [-] 1397621349
2014-04-16 04:09:52+0000 [-] event
2014-04-16 04:09:52+0000 [-] subscribe
2014-04-16 04:09:52+0000 [-]
2014-04-16 04:09:52+0000 [-]
2014-04-16 04:09:52+0000 [-] Unhandled error in Deferred:
2014-04-16 04:09:52+0000 [-] Unhandled Error
Traceback (most recent call last):
File "/var/praekelt/vumi-go/ve/local/lib/python2.7/site-packages/twisted/internet/base.py", line 1201, in mainLoop
self.runUntilCurrent()
File "/var/praekelt/vumi-go/ve/local/lib/python2.7/site-packages/twisted/internet/base.py", line 824, in runUntilCurrent
call.func(*call.args, **call.kw)
File "/var/praekelt/vumi-go/ve/local/lib/python2.7/site-packages/twisted/internet/defer.py", line 382, in callback
self._startRunCallbacks(result)
File "/var/praekelt/vumi-go/ve/local/lib/python2.7/site-packages/twisted/internet/defer.py", line 490, in _startRunCallbacks
self._runCallbacks()
--- ---
File "/var/praekelt/vumi-go/ve/local/lib/python2.7/site-packages/twisted/internet/defer.py", line 577, in _runCallbacks
current.result = callback(current.result, *args, **kw)
File "/var/praekelt/vumi-go/ve/src/vumi/vumi/transports/wechat/wechat.py", line 133, in handle_request
wc_msg = WeChatXMLParser.parse(xml)
File "/var/praekelt/vumi-go/ve/src/vumi/vumi/transports/wechat/message_types.py", line 193, in parse
return klass.from_xml(doc)
File "/var/praekelt/vumi-go/ve/src/vumi/vumi/transports/wechat/message_types.py", line 33, in from_xml
params.append(get_child_value(doc, field))
File "/var/praekelt/vumi-go/ve/src/vumi/vumi/transports/wechat/message_types.py", line 13, in get_child_value
return child.text.strip()
exceptions.AttributeError: 'NoneType' object has no attribute 'strip'
```