Add a workaround for failing tests rather than change marshal.c

Author: mpage

Lib/test/test_importlib/test_abc.py

@@ -801,6 +801,9 @@ def verify_code(self, code_object, *, bytecode_written=False):
             data.extend(self.init._pack_uint32(0))
             data.extend(self.init._pack_uint32(self.loader.source_mtime))
             data.extend(self.init._pack_uint32(self.loader.source_size))
+            # Make sure theres > 1 reference to code_object so that the
+            # marshaled representation below matches the cached representation
+            l = [code_object]
             data.extend(marshal.dumps(code_object))
             self.assertEqual(self.loader.written[self.cached], bytes(data))
 

Python/marshal.c

@@ -384,12 +384,11 @@ w_ref(PyObject *v, char *flag, WFILE *p)
     if (p->version < 3 || p->hashtable == NULL)
         return 0; /* not writing object references */
 
-    /* If it has only one reference, it definitely isn't shared.  But we use
-     * TYPE_REF always for interned string and code objects, to PYC file stable
+    /* If it has only one reference, it definitely isn't shared.
+     * But we use TYPE_REF always for interned string, to PYC file stable
      * as possible.
      */
     if (Py_REFCNT(v) == 1 &&
-            !PyCode_Check(v) &&
             !(PyUnicode_CheckExact(v) && PyUnicode_CHECK_INTERNED(v))) {
         return 0;
     }