This feature only has been implemented properly for Qt port recently on the trunk by Yael (r53947). I think this feature should be disabled for Qt 4.6.x as it is not ready on that branch.
Created attachment 47649 [details]
Turn off websocket support for Qt 4.6.x
Cherry-picked into qtwebkit-4.6 with commit b89d09b3c248d4ea87860aeb26b16e203e47cf7f
Fixed, closing the bug.