Clear textbase text properly.

qutebrowser/mainwindow/statusbar/textbase.py

@@ -58,6 +58,8 @@ class TextBase(QLabel):
         if self.text():
             self._elided_text = self.fontMetrics().elidedText(
                 self.text(), self._elidemode, width, Qt.TextShowMnemonic)
+        else:
+            self._elided_text = ''
 
     def setText(self, txt):
         """Extend QLabel::setText.

tests/mainwindow/statusbar/test_textbase.py

@@ -92,3 +92,12 @@ def test_text_elide_none(mocker, qtbot):
     label._update_elided_text(20)
 
     assert not label.fontMetrics.called
+
+
+def test_unset_text(qtbot):
+    """Make sure the text is cleared properly."""
+    label = TextBase()
+    qtbot.add_widget(label)
+    label.setText('foo')
+    label.setText('')
+    assert not label._elided_text