Better workaround for hang-with-warnings bug

qutebrowser/network/networkmanager.py

@@ -146,27 +146,18 @@ class NetworkManager(QNetworkAccessManager):
             if accept_language is not None:
                 req.setRawHeader('Accept-Language'.encode('ascii'),
                                  accept_language.encode('ascii'))
-            if (op == QNetworkAccessManager.PostOperation and
-                    not req.header(QNetworkRequest.ContentTypeHeader)):
-                # If we don't do this workaround, we get a freeze on
+            with log.disable_qt_msghandler():
+                # If we don't disable our message handler, we get a freeze on
                 # http://ch.mouser.com/localsites/ when clicking on a currency.
-                # We basically do the same thing as Qt would do by itself in
-                # src/network/access/qhttpnetworkrequest.cpp ->
-                # QHttpNetworkRequestPrivate::header but somehow it doesn't
-                # freeze when we do it here.
                 #
                 # FIXME: Open questions:
                 #
                 #   - Shouldn't QtWebPage set the content-type correctly by
                 #     itself?
                 #
-                #   - Why does Qt freeze if we don't do that? Why doesn't it
-                #     happen with the minimal browser? It should really only
-                #     print a warning and nothing else... Maybe message
-                #     handler?!
-                req.setHeader(QNetworkRequest.ContentTypeHeader,
-                               'application/x-www-form-urlencoded')
-            reply = super().createRequest(op, req, outgoing_data)
+                #   - Why does Qt freeze if we don't disable our message
+                #     handler?
+                reply = super().createRequest(op, req, outgoing_data)
             self._requests.append(reply)
             reply.destroyed.connect(lambda obj: self._requests.remove(obj))
         return reply

qutebrowser/utils/log.py

@@ -24,6 +24,7 @@ import os
 import sys
 import cgi
 import logging
+from contextlib import contextmanager
 from logging import getLogger
 from collections import deque
 
@@ -114,6 +115,14 @@ def init_log(args):
     qInstallMessageHandler(qt_message_handler)
 
 
+@contextmanager
+def disable_qt_msghandler():
+    """Contextmanager which temporarely disables the Qt message handler."""
+    old_handler = qInstallMessageHandler(None)
+    yield
+    qInstallMessageHandler(old_handler)
+
+
 def fix_rfc2622():
     """Fix the rfc6266 logger.