Temporarily set JavascriptCanOpenWindows for hints

This partially reverts ba21fb3784.
Fixes #2311.

qutebrowser/browser/webelem.py

@@ -406,12 +406,7 @@ class AbstractWebElement(collections.abc.MutableMapping):
 
         href_tags = ['a', 'area', 'link']
         if click_target == usertypes.ClickTarget.normal:
-            if self.tag_name() in href_tags and self.get('target') == '_blank':
-                log.webelem.debug("target _blank -> Clicking via href")
-                # FIXME:qtwebengine Should we use tab_bg here with
-                # background-tabs set?
-                self._click_href(usertypes.ClickTarget.tab)
-            elif self.tag_name() in href_tags:
+            if self.tag_name() in href_tags:
                 log.webelem.debug("Clicking via JS click()")
                 self._click_js(click_target)
             elif self.is_editable(strict=True):

qutebrowser/browser/webengine/webengineelem.py

@@ -22,8 +22,10 @@
 
 """QtWebEngine specific part of the web element API."""
 
-from PyQt5.QtCore import QRect, Qt, QPoint
+from PyQt5.QtCore import QRect, Qt, QPoint, QEventLoop
 from PyQt5.QtGui import QMouseEvent
+from PyQt5.QtWidgets import QApplication
+from PyQt5.QtWebEngineWidgets import QWebEngineSettings
 
 from qutebrowser.utils import log, javascript
 from qutebrowser.browser import webelem
@@ -169,5 +171,21 @@ class WebEngineElement(webelem.AbstractWebElement):
         self._tab.run_js_async(js_code)
 
     def _click_js(self, _click_target):
+        settings = QWebEngineSettings.globalSettings()
+        attribute = QWebEngineSettings.JavascriptCanOpenWindows
+        could_open_windows = settings.testAttribute(attribute)
+        settings.setAttribute(attribute, True)
+
+        # Get QtWebEngine do apply the settings
+        # (it does so with a 0ms QTimer...)
+        # This is also used in Qt's tests:
+        # https://github.com/qt/qtwebengine/commit/5e572e88efa7ba7c2b9138ec19e606d3e345ac90
+        qapp = QApplication.instance()
+        qapp.processEvents(QEventLoop.ExcludeSocketNotifiers |
+                           QEventLoop.ExcludeUserInputEvents)
+
+        def reset_setting(_arg):
+            settings.setAttribute(attribute, could_open_windows)
+
         js_code = javascript.assemble('webelem', 'click', self._id)
-        self._tab.run_js_async(js_code)
+        self._tab.run_js_async(js_code, reset_setting)

qutebrowser/browser/webkit/webkitelem.py

@@ -20,7 +20,7 @@
 """QtWebKit specific part of the web element API."""
 
 from PyQt5.QtCore import QRect
-from PyQt5.QtWebKit import QWebElement
+from PyQt5.QtWebKit import QWebElement, QWebSettings
 
 from qutebrowser.config import config
 from qutebrowser.utils import log, utils, javascript
@@ -301,11 +301,12 @@ class WebKitElement(webelem.AbstractWebElement):
         self._elem.evaluateJavaScript('this.focus();')
 
     def _click_js(self, click_target):
-        if self.get('target') == '_blank':
-            # QtWebKit does nothing in this case for some reason...
-            self._click_fake_event(click_target)
-        else:
-            self._elem.evaluateJavaScript('this.click();')
+        settings = QWebSettings.globalSettings()
+        attribute = QWebSettings.JavascriptCanOpenWindows
+        could_open_windows = settings.testAttribute(attribute)
+        settings.setAttribute(attribute, True)
+        self._elem.evaluateJavaScript('this.click();')
+        settings.setAttribute(attribute, could_open_windows)
 
     def _click_fake_event(self, click_target):
         self._tab.data.override_target = click_target