itemmodels.AbstractSortTableModel: Fix mapFromSourceRows

Author: janezd

Orange/widgets/utils/itemmodels.py

@@ -127,7 +127,10 @@ def mapToSourceRows(self, rows):
             Source rows matching input rows. If they are the same,
             simply input `rows` is returned.
         """
-        if self.__sortInd is not None:
+        # self.__sortInd[rows] fails if `rows` is an empty list or array
+        if self.__sortInd is not None \
+                and (isinstance(rows, (int, type(Ellipsis)))
+                     or len(rows)):
             new_rows = self.__sortInd[rows]
             if rows is Ellipsis:
                 new_rows.setflags(write=False)

Orange/widgets/utils/tests/test_itemmodels.py

@@ -3,6 +3,8 @@
 
 from unittest import TestCase
 
+import numpy as np
+
 from AnyQt.QtCore import Qt
 
 from Orange.data import Domain, ContinuousVariable, DiscreteVariable
@@ -133,6 +135,24 @@ def test_sorting(self):
         self.model.sort(1, Qt.DescendingOrder)
         self.assertSequenceEqual(self.model.mapToSourceRows(...).tolist(), [0, 1])
 
+    def test_mapToSourceRows(self):
+        self.model.sort(1, Qt.AscendingOrder)
+        self.assertSequenceEqual(
+            self.model.mapToSourceRows(...).tolist(),
+            [1, 0])
+        self.assertEqual(
+            self.model.mapToSourceRows(1).tolist(),
+            0)
+        self.assertSequenceEqual(
+            self.model.mapToSourceRows([1, 0]).tolist(),
+            [0, 1])
+        self.assertSequenceEqual(
+            self.model.mapToSourceRows([]),
+            [])
+        self.assertSequenceEqual(
+            self.model.mapToSourceRows(np.array([], dtype=int)).tolist(),
+            [])
+
 
 class TestPyListModel(TestCase):
     @classmethod