Implement Qt 5.11 devtools support

See #3010

doc/changelog.asciidoc

@@ -51,6 +51,8 @@ Changed
   one), which allows scripts like OneeChan to work.
 - Rapid hinting is now supported with the `yank` and `yank-primary` targets,
   copying newline-separated links.
+- QtWebEngine: On Qt 5.11, the developer tools (inspector) can now be used
+  securely and without requiring the `--enable-webengine-inspector` option.
 
 Removed
 ~~~~~~~

doc/qutebrowser.1.asciidoc

@@ -60,7 +60,7 @@ show it.
     Which backend to use.
 
 *--enable-webengine-inspector*::
-    Enable the web inspector for QtWebEngine. Note that this is a SECURITY RISK and you should not visit untrusted websites with the inspector turned on. See https://bugreports.qt.io/browse/QTBUG-50725 for more details.
+    Enable the web inspector for QtWebEngine. Note that this is a SECURITY RISK and you should not visit untrusted websites with the inspector turned on. See https://bugreports.qt.io/browse/QTBUG-50725 for more details. This is not needed anymore since Qt 5.11 where the inspector is always enabled and secure.
 
 === debug arguments
 *-l* '{critical,error,warning,info,debug,vdebug}', *--loglevel* '{critical,error,warning,info,debug,vdebug}'::

qutebrowser/browser/webengine/webengineinspector.py

@@ -39,8 +39,8 @@ class WebEngineInspector(inspector.AbstractWebInspector):
         settings.setAttribute(QWebEngineSettings.JavascriptEnabled, True)
         self._set_widget(view)
 
-    def inspect(self, _page):
-        """Set up the inspector."""
+    def _inspect_old(self):
+        """Set up the inspector for Qt < 5.11."""
         try:
             port = int(os.environ['QTWEBENGINE_REMOTE_DEBUGGING'])
         except KeyError:
@@ -49,4 +49,14 @@ class WebEngineInspector(inspector.AbstractWebInspector):
                 "'qutebrowser --help' for details.")
         url = QUrl('http://localhost:{}/'.format(port))
         self._widget.load(url)
+
+    def _inspect_new(self, page):
+        """Set up the inspector for Qt >= 5.11."""
+        self._widget.page().setInspectedPage(page)
+
+    def inspect(self, page):
+        try:
+            self._inspect_new(page)
+        except AttributeError:
+            self._inspect_old()
         self.show()

qutebrowser/browser/webengine/webenginesettings.py

@@ -27,7 +27,8 @@ Module attributes:
 import os
 
 from PyQt5.QtGui import QFont
-from PyQt5.QtWebEngineWidgets import QWebEngineSettings, QWebEngineProfile
+from PyQt5.QtWebEngineWidgets import (QWebEngineSettings, QWebEngineProfile,
+                                      QWebEnginePage)
 
 from qutebrowser.browser.webengine import spell
 from qutebrowser.config import config, websettings
@@ -274,7 +275,8 @@ def _init_profiles():
 
 def init(args):
     """Initialize the global QWebSettings."""
-    if args.enable_webengine_inspector:
+    if (args.enable_webengine_inspector and
+            not hasattr(QWebEnginePage, 'setInspectedPage')):  # only Qt < 5.11
         os.environ['QTWEBENGINE_REMOTE_DEBUGGING'] = str(utils.random_port())
 
     _init_profiles()

qutebrowser/qutebrowser.py

@@ -86,7 +86,9 @@ def get_argparser():
                         "that this is a SECURITY RISK and you should not "
                         "visit untrusted websites with the inspector turned "
                         "on. See https://bugreports.qt.io/browse/QTBUG-50725 "
-                        "for more details.")
+                        "for more details. This is not needed anymore since "
+                        "Qt 5.11 where the inspector is always enabled and "
+                        "secure.")
 
     parser.add_argument('--json-args', help=argparse.SUPPRESS)
     parser.add_argument('--temp-basedir-restarted', help=argparse.SUPPRESS)

tests/end2end/features/misc.feature

@@ -163,7 +163,7 @@ Feature: Various utility commands.
         And I run :inspector
         Then the error "Please enable content.developer_extras before using the webinspector!" should be shown
 
-    @qtwebkit_skip
+    @qtwebkit_skip @qt<5.11
     Scenario: Inspector without --enable-webengine-inspector
         When I run :inspector
         Then the error "QtWebEngine inspector is not enabled. See 'qutebrowser --help' for details." should be shown

tests/end2end/test_invocations.py

@@ -26,9 +26,10 @@ import logging
 import re
 
 import pytest
-
 from PyQt5.QtCore import QProcess, qVersion
 
+from tests import utils
+
 
 ascii_locale = pytest.mark.skipif(sys.hexversion >= 0x03070000,
                                   reason="Python >= 3.7 doesn't force ASCII "
@@ -257,6 +258,7 @@ def test_qt_arg(request, quteproc_new, tmpdir):
     quteproc_new.wait_for_quit()
 
 
+@utils.skip_qt511
 def test_webengine_inspector(request, quteproc_new):
     if not request.config.webengine:
         pytest.skip()

tests/helpers/utils.py

@@ -36,6 +36,8 @@ qt58 = pytest.mark.skipif(
     qtutils.version_check('5.9'), reason="Needs Qt 5.8 or earlier")
 qt59 = pytest.mark.skipif(
     not qtutils.version_check('5.9'), reason="Needs Qt 5.9 or newer")
+skip_qt511 = pytest.mark.skipif(
+    qtutils.version_check('5.11'), reason="Needs Qt 5.10 or earlier")
 
 
 class PartialCompareOutcome: