Handle case for PyStructSequence with unnamed fields

python · serhiy-storchaka · Oct 4, 2023 · Oct 3, 2023 · Oct 3, 2023 · Oct 3, 2023
commit 981e40371a20f153abe34137b02211e90414eb42
diff --git a/Lib/test/test_structseq.py b/Lib/test/test_structseq.py
@@ -109,6 +109,21 @@ def test_constructor_with_duplicate_fields(self):
         with self.assertRaisesRegex(TypeError, "got multiple values for field 'tm_mon'"):
             t("123456789", dict={"error": 0, "tm_zone": "some zone", "tm_mon": 1})
 
+    def test_constructor_with_duplicate_unnamed_fields(self):
+        assert os.stat_result.n_unnamed_fields > 0
+        n_visible_fields = os.stat_result.n_sequence_fields
+
+        r = os.stat_result(range(n_visible_fields), {'st_atime': -1.0})
+        self.assertEqual(r.st_atime, -1.0)
+        self.assertEqual(r, tuple(range(n_visible_fields)))
+
+        r = os.stat_result((*range(n_visible_fields), -1.0))
+        self.assertEqual(r.st_atime, -1.0)
+        self.assertEqual(r, tuple(range(n_visible_fields)))
+
+        with self.assertRaisesRegex(TypeError, "got multiple values for field 'st_atime'"):
+            os.stat_result((*range(n_visible_fields), -1.0), {'st_atime': -1.0})
+
     def test_constructor_with_unknown_fields(self):
         t = time.struct_time
         with self.assertRaisesRegex(TypeError,

diff --git a/Objects/structseq.c b/Objects/structseq.c
@@ -219,7 +219,7 @@ structseq_new_impl(PyTypeObject *type, PyObject *arg, PyObject *dict)
     if (dict != NULL) {
         for (i = 0; i < len; ++i) {
             // unnamed fields can be present in both sequence and dict
-            if (i >= min_len - n_unnamed_fields && i < min_len + n_unnamed_fields
+            if (i >= min_len - n_unnamed_fields && i < min_len) {
                 continue;
             }
 
@@ -243,7 +243,7 @@ structseq_new_impl(PyTypeObject *type, PyObject *arg, PyObject *dict)
             Py_DECREF(res);
             return NULL;
         }
-        for (i = len; i < max_len; ++i) {
+        for (i = min_len; i < max_len; ++i) {
             PyObject *ob = NULL;
             const char *name = type->tp_members[i - n_unnamed_fields].name;
             PyObject *key = PyUnicode_FromString(name);