Tweaks from review feedback (thanks!)

Author: duaneg

Lib/test/test_marshal.py

@@ -409,7 +409,8 @@ def test_deterministic_sets(self):
                     self.assertEqual(dump_0, dump_1)
 
     def test_unmarshallable(self):
-        # gh-106287
+        # Check no crash after encountering unmarshallable objects.
+        # See https://github.com/python/cpython/issues/106287
         fset = frozenset([int])
         code = compile("a = 1", "<string>", "exec")
         code = code.replace(co_consts=(1, fset, None))
@@ -427,6 +428,7 @@ def test_unmarshallable(self):
                 with self.assertRaisesRegex(ValueError, "unmarshallable object"):
                     marshal.dumps((arg, memoryview(b'')))
 
+
 LARGE_SIZE = 2**31
 pointer_size = 8 if sys.maxsize > 0xFFFFFFFF else 4
 

Python/marshal.c

@@ -431,8 +431,9 @@ w_object(PyObject *v, WFILE *p)
 {
     char flag = '\0';
 
-    if (p->error != WFERR_OK)
+    if (p->error != WFERR_OK) {
         return;
+    }
 
     p->depth++;
 
@@ -753,10 +754,6 @@ PyMarshal_WriteLongToFile(long x, FILE *fp, int version)
     w_flush(&wf);
 }
 
-/* TODO: Contrary to its documentation, this function does NOT set an error on
- * failure. It is not used internally except from test code, where this doesn't
- * matter, but this discrepancy might cause problems for any external code
- * using it. */
 void
 PyMarshal_WriteObjectToFile(PyObject *x, FILE *fp, int version)
 {