Allow to set message clear timer to 0

Fixes #2527

CHANGELOG.asciidoc

@@ -44,6 +44,7 @@ Changed
 - The HTTP cache is disabled with QtWebKit on Qt 5.8 now as it leads to frequent
   crashes due to a Qt bug.
 - stdin is now closed immediately for processes spawned from qutebrowser
+- When ui -> message-timeout is set to 0, messages are now never cleared.
 
 Fixed
 ~~~~~

doc/help/settings.asciidoc

@@ -581,6 +581,7 @@ Default: +pass:[bottom]+
 [[ui-message-timeout]]
 === message-timeout
 Time (in ms) to show messages in the statusbar for.
+Set to 0 to never clear messages.
 
 Default: +pass:[2000]+
 

qutebrowser/config/configdata.py

@@ -317,8 +317,9 @@ def data(readonly=False):
              "The position of the status bar."),
 
             ('message-timeout',
-             SettingValue(typ.Int(), '2000'),
+             SettingValue(typ.Int(minval=0), '2000'),
-             "Time (in ms) to show messages in the statusbar for."),
+             "Time (in ms) to show messages in the statusbar for.\n"
+             "Set to 0 to never clear messages."),
 
             ('message-unfocused',
              SettingValue(typ.Bool(), 'false'),

qutebrowser/mainwindow/messageview.py

@@ -98,7 +98,9 @@ class MessageView(QWidget):
     @config.change_filter('ui', 'message-timeout')
     def _set_clear_timer_interval(self):
         """Configure self._clear_timer according to the config."""
-        self._clear_timer.setInterval(config.get('ui', 'message-timeout'))
+        interval = config.get('ui', 'message-timeout')
+        if interval != 0:
+            self._clear_timer.setInterval(interval)
 
     @pyqtSlot()
     def clear_messages(self):
@@ -125,6 +127,7 @@ class MessageView(QWidget):
         widget = Message(level, text, replace=replace, parent=self)
         self._vbox.addWidget(widget)
         widget.show()
+        if config.get('ui', 'message-timeout') != 0:
             self._clear_timer.start()
         self._messages.append(widget)
         self._last_text = text