Merge branch 'rcorre-fix_completion_crashes'

qutebrowser/completion/completionwidget.py

@@ -30,7 +30,7 @@ from PyQt5.QtCore import (pyqtSlot, pyqtSignal, Qt, QItemSelectionModel,
 from qutebrowser.config import config, style
 from qutebrowser.completion import completiondelegate
 from qutebrowser.completion.models import base
-from qutebrowser.utils import qtutils, objreg, utils, usertypes
+from qutebrowser.utils import objreg, utils, usertypes
 from qutebrowser.commands import cmdexc, cmdutils
 
 
@@ -192,9 +192,17 @@ class CompletionView(QTreeView):
         Args:
             prev: True for prev item, False for next one.
         """
+        # selmodel can be None if 'show' and 'auto-open' are set to False
+        # https://github.com/The-Compiler/qutebrowser/issues/1731
+        selmodel = self.selectionModel()
+        if selmodel is None:
+            return
+
         idx = self._next_idx(prev)
-        qtutils.ensure_valid(idx)
-        self.selectionModel().setCurrentIndex(
+        if not idx.isValid():
+            return
+
+        selmodel.setCurrentIndex(
             idx, QItemSelectionModel.ClearAndSelect | QItemSelectionModel.Rows)
 
     def set_model(self, model):

tests/unit/completion/test_completionwidget.py

@@ -119,6 +119,8 @@ def test_maybe_resize_completion(completionview, config_stub, qtbot):
     ([['Aa'], []], -1, 'Aa'),
     ([['Aa'], [], []], 1, 'Aa'),
     ([['Aa'], [], []], -1, 'Aa'),
+    ([[]], 1, None),
+    ([[]], -1, None),
 ])
 def test_completion_item_next_prev(tree, count, expected, completionview):
     """Test that on_next_prev_item moves the selection properly.
@@ -146,3 +148,13 @@ def test_completion_item_next_prev(tree, count, expected, completionview):
             completionview.completion_item_next()
     idx = completionview.selectionModel().currentIndex()
     assert filtermodel.data(idx) == expected
+
+
+def test_completion_item_next_prev_no_model(completionview):
+    """Test that next/prev won't crash with no model set.
+
+    This can happen if completion.show and completion.auto-open are False.
+    Regression test for issue #1722.
+    """
+    completionview.completion_item_prev()
+    completionview.completion_item_next()