Fix bytes.__setitem__ slice for inversed range

youknowone · youknowone · commit 18fe9672eec6 · 2020-04-13T03:56:46.000+09:00
diff --git a/Lib/test/test_bytes.py b/Lib/test/test_bytes.py
@@ -1299,7 +1299,8 @@ def test_delitem(self):
         del b[4]
         self.assertEqual(b, bytearray([1, 2, 3, 4, 6, 7, 8]))
 
-    @unittest.skip("TODO: RUSTPYTHON")
+    # TODO: RUSTPYTHON
+    @unittest.expectedFailure
     def test_setslice(self):
         b = bytearray(range(10))
         self.assertEqual(list(b), list(range(10)))
diff --git a/vm/src/obj/objbyteinner.rs b/vm/src/obj/objbyteinner.rs
@@ -456,9 +456,12 @@ impl PyByteInner {
             }),
         };
         let items = sec?;
-        let range = self
+        let mut range = self
             .elements
             .get_slice_range(&slice.start_index(vm)?, &slice.stop_index(vm)?);
+        if range.end < range.start {
+            range.end = range.start;
+        }
         self.elements.splice(range, items);
         Ok(vm
             .ctx
