Cancel permission prompt when tab is closed.

Fixes #1250.

CHANGELOG.asciidoc

@@ -36,6 +36,8 @@ Fixed
 - Fixed starting with -c "".
 - Fixed crash when a tab is closed twice via javascript (e.g. Dropbox
   authentication dialogs)
+- Fixed crash when a notification/geolocation prompt is answered after closing
+  the tab it belongs to.
 
 v0.5.1
 ------

qutebrowser/browser/webpage.py

@@ -372,6 +372,7 @@ class BrowserPage(QWebPage):
             q.answered_no.connect(no_action)
             q.cancelled.connect(no_action)
 
+            self.shutting_down.connect(q.abort)
             q.completed.connect(q.deleteLater)
 
             self.featurePermissionRequestCanceled.connect(functools.partial(

tests/integration/features/prompts.feature

@@ -178,6 +178,15 @@ Feature: Prompts
         And I run :leave-mode
         Then the javascript message "notification permission aborted" should be logged
 
+    Scenario: answering notification after closing tab
+        When I set content -> notifications to ask
+        And I open data/prompt/notifications.html in a new tab
+        And I click the button
+        And I wait for a prompt
+        And I run :tab-close
+        And I wait for "Leaving mode KeyMode.yesno (reason: aborted)" in the log
+        Then no crash should happen
+
     # Page authentication
 
     Scenario: Successful webpage authentification