Exception deleting asset in web admin.

[mike]

Repro Steps

1. Connect to web admin
2. Select the asset tab
3. List groups
4. Click a group
5. Click delete on an asset

Expected

The asset is deleted.

Observed

07/19/11 22:27:25	None	0	HTTPChannel,36,127.0.0.1	Traceback (most recent call last):
07/19/11 22:27:25	None	0	HTTPChannel,36,127.0.0.1	  File "F:\Projects\Twisted\trunk\twisted\internet\defer.py", line 297, in addCallback
07/19/11 22:27:25	None	0	HTTPChannel,36,127.0.0.1	    callbackKeywords=kw)
07/19/11 22:27:25	None	0	HTTPChannel,36,127.0.0.1	  File "F:\Projects\Twisted\trunk\twisted\internet\defer.py", line 286, in addCallbacks
07/19/11 22:27:25	None	0	HTTPChannel,36,127.0.0.1	    self._runCallbacks()
07/19/11 22:27:25	None	0	HTTPChannel,36,127.0.0.1	  File "F:\Projects\Twisted\trunk\twisted\internet\defer.py", line 542, in _runCallbacks
07/19/11 22:27:25	None	0	HTTPChannel,36,127.0.0.1	    current.result = callback(current.result, *args, **kw)
07/19/11 22:27:25	None	0	HTTPChannel,36,127.0.0.1	  File "F:\Projects\Divmod\trunk\Nevow\nevow\flat\twist.py", line 42, in cb
07/19/11 22:27:25	None	0	HTTPChannel,36,127.0.0.1	    _drive(iterable, finished)
07/19/11 22:27:25	None	0	HTTPChannel,36,127.0.0.1	--- <exception caught here> ---
07/19/11 22:27:25	None	0	HTTPChannel,36,127.0.0.1	  File "F:\Projects\Divmod\trunk\Nevow\nevow\flat\twist.py", line 24, in _drive
07/19/11 22:27:25	None	0	HTTPChannel,36,127.0.0.1	    next = iterable.next()
07/19/11 22:27:25	None	0	HTTPChannel,36,127.0.0.1	  File "F:\Projects\Divmod\trunk\Nevow\nevow\flat\ten.py", line 83, in iterflatten
07/19/11 22:27:25	None	0	HTTPChannel,36,127.0.0.1	    for item in gen:
07/19/11 22:27:25	None	0	HTTPChannel,36,127.0.0.1	  File "F:\Projects\Divmod\trunk\Nevow\nevow\flat\flatstan.py", line 103, in TagSerializer
07/19/11 22:27:25	None	0	HTTPChannel,36,127.0.0.1	    yield serialize(toBeRenderedBy, context)
07/19/11 22:27:25	None	0	HTTPChannel,36,127.0.0.1	  File "F:\Projects\Divmod\trunk\Nevow\nevow\flat\ten.py", line 70, in serialize
07/19/11 22:27:25	None	0	HTTPChannel,36,127.0.0.1	    return partialflatten(context, obj)
07/19/11 22:27:25	None	0	HTTPChannel,36,127.0.0.1	  File "F:\Projects\Divmod\trunk\Nevow\nevow\flat\ten.py", line 61, in partialflatten
07/19/11 22:27:25	None	0	HTTPChannel,36,127.0.0.1	    return flattener(obj, context)
07/19/11 22:27:25	None	0	HTTPChannel,36,127.0.0.1	  File "F:\Projects\Divmod\trunk\Nevow\nevow\flat\flatstan.py", line 264, in DirectiveSerializer
07/19/11 22:27:25	None	0	HTTPChannel,36,127.0.0.1	    return serialize(renderer, context)
07/19/11 22:27:25	None	0	HTTPChannel,36,127.0.0.1	  File "F:\Projects\Divmod\trunk\Nevow\nevow\flat\ten.py", line 70, in serialize
07/19/11 22:27:25	None	0	HTTPChannel,36,127.0.0.1	    return partialflatten(context, obj)
07/19/11 22:27:25	None	0	HTTPChannel,36,127.0.0.1	  File "F:\Projects\Divmod\trunk\Nevow\nevow\flat\ten.py", line 61, in partialflatten
07/19/11 22:27:25	None	0	HTTPChannel,36,127.0.0.1	    return flattener(obj, context)
07/19/11 22:27:25	None	0	HTTPChannel,36,127.0.0.1	  File "F:\Projects\Divmod\trunk\Nevow\nevow\flat\flatstan.py", line 247, in MethodSerializer
07/19/11 22:27:25	None	0	HTTPChannel,36,127.0.0.1	    return FunctionSerializer(original, context, nocontext)
07/19/11 22:27:25	None	0	HTTPChannel,36,127.0.0.1	  File "F:\Projects\Divmod\trunk\Nevow\nevow\flat\flatstan.py", line 236, in FunctionSerializer
07/19/11 22:27:25	None	0	HTTPChannel,36,127.0.0.1	    result = original(context, data)
07/19/11 22:27:25	None	0	HTTPChannel,36,127.0.0.1	  File "mv3d\server\editor.py", line 1227, in render_checkPost
07/19/11 22:27:25	None	0	HTTPChannel,36,127.0.0.1	    group = self.target.parent.getAssetGroup(self.target.aid[0])
07/19/11 22:27:25	None	0	HTTPChannel,36,127.0.0.1	exceptions.AttributeError: 'NoneType' object has no attribute 'getAssetGroup'