Add proxy support for QtWebEngine with Qt >= 5.8

See #666
Fixes #2082

qutebrowser/app.py

@@ -47,6 +47,7 @@ from qutebrowser.commands import cmdutils, runners, cmdexc
 from qutebrowser.config import style, config, websettings, configexc
 from qutebrowser.browser import (urlmarks, adblock, history, browsertab,
                                  downloads)
+from qutebrowser.browser.network import proxy
 from qutebrowser.browser.webkit import cookies, cache
 from qutebrowser.browser.webkit.network import networkmanager
 from qutebrowser.keyinput import macros
@@ -386,6 +387,11 @@ def _init_modules(args, crash_handler):
     log.init.debug("Initializing network...")
     networkmanager.init()
 
+    if qtutils.version_check('5.8'):
+        # Otherwise we can only initialize it for QtWebKit because of crashes
+        log.init.debug("Initializing proxy...")
+        proxy.init()
+
     log.init.debug("Initializing readline-bridge...")
     readline_bridge = readline.ReadlineBridge()
     objreg.register('readline-bridge', readline_bridge)

qutebrowser/browser/webkit/webkittab.py

@@ -42,6 +42,8 @@ def init():
     """Initialize QtWebKit-specific modules."""
     qapp = QApplication.instance()
 
+    if not qtutils.version_check('5.8'):
+        # Otherwise we initialize it globally in app.py
         log.init.debug("Initializing proxy...")
         proxy.init()
 

qutebrowser/config/configdata.py

@@ -35,7 +35,7 @@ from qutebrowser.config import configtypes as typ
 from qutebrowser.config import sections as sect
 from qutebrowser.config.value import SettingValue
 from qutebrowser.utils.qtutils import MAXVALS
-from qutebrowser.utils import usertypes
+from qutebrowser.utils import usertypes, qtutils
 
 
 FIRST_COMMENT = r"""
@@ -433,7 +433,8 @@ def data(readonly=False):
 
             ('proxy',
              SettingValue(typ.Proxy(), 'system',
-                          backends=[usertypes.Backend.QtWebKit]),
+                          backends=(None if qtutils.version_check('5.8')
+                                    else [usertypes.Backend.QtWebKit])),
              "The proxy to use.\n\n"
              "In addition to the listed values, you can use a `socks://...` "
              "or `http://...` URL."),