Remove Qt 5.8 support and tests

With QtWebKit it's probably okay to still use it (*cough* Hyperbola
GNU/Linux-libre^tm *cough*), and only blacklisting it with QtWebEngine would be
quite some effort.

Fixes #3608

qutebrowser/browser/webengine/webenginetab.py

@@ -703,10 +703,6 @@ class WebEngineTab(browsertab.AbstractTab):
     def shutdown(self):
         self.shutting_down.emit()
         self.action.exit_fullscreen()
-        if qtutils.version_check('5.8', exact=True, compiled=False):
-            # WORKAROUND for
-            # https://bugreports.qt.io/browse/QTBUG-58563
-            self.search.clear()
         self._widget.shutdown()
 
     def reload(self, *, force=False):

qutebrowser/misc/earlyinit.py

@@ -172,6 +172,7 @@ def check_qt_version():
     from PyQt5.QtCore import (qVersion, QT_VERSION, PYQT_VERSION,
                               PYQT_VERSION_STR)
     from pkg_resources import parse_version
+    from qutebrowser.utils import log
     if (QT_VERSION < 0x050701 or PYQT_VERSION < 0x050700 or
             parse_version(qVersion()) < parse_version('5.7.1')):
         text = ("Fatal error: Qt >= 5.7.1 and PyQt >= 5.7 are required, "
@@ -179,6 +180,10 @@ def check_qt_version():
                                                            PYQT_VERSION_STR))
         _die(text)
 
+    if qVersion().startswith('5.8.'):
+        log.init.warning("Running qutebrowser with Qt 5.8 is untested and "
+                         "unsupported!")
+
 
 def check_ssl_support():
     """Check if SSL support is available."""

qutebrowser/misc/miscwidgets.py

@@ -260,16 +260,6 @@ class WrapperLayout(QLayout):
         self._widget = widget
         container.setFocusProxy(widget)
         widget.setParent(container)
-        if (qtutils.version_check('5.8.0', exact=True, compiled=False) and
-                objects.backend == usertypes.Backend.QtWebEngine and
-                container.window() and
-                container.window().windowHandle() and
-                not container.window().windowHandle().isActive()):
-            log.misc.debug("Calling QApplication::sync...")
-            # WORKAROUND for:
-            # https://bugreports.qt.io/browse/QTBUG-56652
-            # https://codereview.qt-project.org/#/c/176113/5//ALL,unified
-            QApplication.sync()
 
     def unwrap(self):
         self._widget.setParent(None)

tests/end2end/features/tabs.feature

@@ -632,12 +632,6 @@ Feature: Tab management
 
     # https://github.com/qutebrowser/qutebrowser/issues/2289
 
-    @qtwebkit_skip @qt==5.8.0
-    Scenario: Cloning a tab with a special URL
-        When I open chrome://gpu
-        And I run :tab-clone
-        Then the error "Can't serialize special URL!" should be shown
-
     @qtwebkit_skip @qt<5.9
     Scenario: Cloning a tab with a view-source URL
         When I open /

tox.ini

@@ -13,8 +13,8 @@ skipsdist = true
 setenv =
     QT_QPA_PLATFORM_PLUGIN_PATH={envdir}/Lib/site-packages/PyQt5/plugins/platforms
     PYTEST_QT_API=pyqt5
-    pyqt{,56,571,58,59,510}: LINK_PYQT_SKIP=true
-    pyqt{,56,571,58,59,510}: QUTE_BDD_WEBENGINE=true
+    pyqt{,56,571,59,510}: LINK_PYQT_SKIP=true
+    pyqt{,56,571,59,510}: QUTE_BDD_WEBENGINE=true
     cov: PYTEST_ADDOPTS=--cov --cov-report xml --cov-report=html --cov-report=
 passenv = PYTHON DISPLAY XAUTHORITY HOME USERNAME USER CI TRAVIS XDG_* QUTE_* DOCKER
 basepython =
@@ -26,7 +26,6 @@ deps =
     -r{toxinidir}/misc/requirements/requirements-tests.txt
     pyqt: -r{toxinidir}/misc/requirements/requirements-pyqt.txt
     pyqt571: PyQt5==5.7.1
-    pyqt58: PyQt5==5.8.2
     pyqt59: PyQt5==5.9.2
     pyqt510: PyQt5==5.10.1
 commands =