Fix downward slices for positive base arrays

BCSharp · Dec 6, 2024 · 699824b · 699824b
1 parent 84de081
commit 699824b
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Showing 2 changed files with 17 additions and 1 deletion.
diff --git a/Src/IronPython/Runtime/Operations/ArrayOps.cs b/Src/IronPython/Runtime/Operations/ArrayOps.cs
@@ -495,7 +495,7 @@ private static void FixSlice(Slice slice, Array a, out int ostart, out int ostop
                     if (ostop < 0 && lb >= 0) {
                         ostop += ub + 1;
                     }
-                    if (ostop < 0) {
+                    if (ostop < lb) {
                         ostop = ostep > 0 ? lb : lb - 1;
                     }
                 } else if (ostop > ub) {

diff --git a/Tests/test_array.py b/Tests/test_array.py
@@ -497,4 +497,20 @@ def test_equality_rank(self):
         self.assertTrue(c != d)
         self.assertFalse(d != d1)
 
+    def test_slice_down(self):
+        #arr = System.Array[int]((2, 3, 4), base=2)
+        arr = System.Array.CreateInstance(int, (3,), (2,))
+        for i in range(2, 2 + 3):
+            arr[i] = i
+
+        self.assertEqual(arr[-1:-4:-1], System.Array[int]((4, 3, 2)))
+        self.assertEqual(arr[-1:-5:-1], System.Array[int]((4, 3, 2)))
+        self.assertEqual(arr[-1:-6:-1], System.Array[int]((4, 3, 2)))
+
+        self.assertEqual(arr[2:1:-1], System.Array[int]((2,)))
+        self.assertEqual(arr[2:-5:-1], System.Array[int]((2,)))
+        self.assertEqual(arr[2:-6:-1], System.Array[int]((2,)))
+        self.assertEqual(arr[1:-5:-1], System.Array[int](()))
+        self.assertEqual(arr[0:-5:-1], System.Array[int](()))
+
 run_test(__name__)