twisted.web.xmlrpc._QueryFactory.parseResponse fails to errback for a particular malformed response

[toranin]

(applies to 8.1.0, maybe newer)

If the server returns XML that parses but contains no data, an IndexError is thrown from line 321, in the else part of the try/except block that is supposed to catch problems with the response structure.

I moved the indexing operation in question into the try block in the attached patch.

[toranin]

Fix for this issue in twisted.web.xmlrpc in version 8.1.0

[exarkun]

What response provokes this?

[toranin]

Here's the response:

Date: Wed, 27 Aug 2008 19:24:45 UTC
Content-Type: text/xml
Connection: close
Cache-control: private
Content-Length: 99

<?xml version="1.0"?>
<methodResponse>
 <params>
  <param>
  </param>
 </params>
</methodResponse>

It's produced by an in-house server with a couple of bugs, and that will be fixed at some point. Nonetheless, twisted's xmlrpc handler ought not to 'hang' when presented with this.

[therve]

(In [24664]) Branching to 'xmlrpc-empty-response-3399'

[therve]

(In [24666]) Apply the fix, with a test.

Refs #3399

[therve]

Please review!

[exarkun]

The comment in test_parseResponseWithoutData isn't quite right. The failure mode is that it parseResponse raises IndexError, right?

[therve]

Hum I got confused. It should be better now.

[exarkun]

Looks better. twisted.web.xmlrpc.Proxy.callRemote could perhaps use some documentation regarding its errors (well, it has no documentation at all right now). This change adds a new way it can fail, so it would be good to at least mention that.

Merge when you're happy with it.

[therve]

(In [24679]) Merge xmlrpc-empty-response-3399

Author: therve Reviewer: exarkun Fixes #3399

Fix xmlrpc client so that he manages to return an error for buggy servers sending an empty response.