Created attachment 203955 [details]
Testcase. Put it in the same dir of the python file.
The page hangs for a few seconds then the following error is printed
(WebKitWebProcess:4793): GLib-GIO-WARNING **: g_simple_async_result_complete() called from wrong context!
Attaching a testcase. I have tested with Webkit 2.0.2, I'll also test with master as soon as I have the source pulled and built.
Created attachment 203956 [details]
At the moment I can't test on master because of https://bugs.webkit.org/show_bug.cgi?id=117178
I confirmed this happens on latest master too.