Ignore empty js statusbar messages.

qutebrowser/widgets/mainwindow.py

@@ -84,7 +84,8 @@ class MainWindow(QWidget):
         self.tabs.cur_load_started.connect(self.status.prog.on_load_started)
         self.tabs.cur_scroll_perc_changed.connect(
             self.status.percentage.set_perc)
-        self.tabs.cur_statusbar_message.connect(self.status.txt.set_normaltext)
+        self.tabs.cur_statusbar_message.connect(
+            self.status.txt.on_statusbar_message)
         self.tabs.cur_temp_message.connect(self.status.txt.set_temptext)
         self.tabs.cur_url_changed.connect(self.status.url.set_url)
         self.tabs.cur_link_hovered.connect(self.status.url.set_hover_url)

qutebrowser/widgets/statusbar.py

@@ -543,6 +543,17 @@ class _Text(TextBase):
         """Setter for normaltext, to be used as Qt slot."""
         self.normaltext = val
 
+    @pyqtSlot(str)
+    def on_statusbar_message(self, val):
+        """Called when javascript tries to set a statusbar message.
+
+        For some reason, this is emitted a lot with an empty string during page
+        load, so we currently ignore these and thus don't support clearing the
+        message, which is a bit unfortunate...
+        """
+        if val:
+            self.temptext = val
+
     @pyqtSlot(str)
     def set_temptext(self, val):
         """Setter for temptext, to be used as Qt slot."""