Issue #9928: Properly initialize the types exported by the bz2 module.

Misc/NEWS

@@ -62,6 +62,8 @@ Core and Builtins
 Library
 -------
 
+- Issue #9928: Properly initialize the types exported by the bz2 module.
+
 - Issue #1675951: Allow GzipFile to work with unseekable file objects.
   Patch by Florian Festi.
 

Modules/bz2module.c

@@ -2155,9 +2155,12 @@ PyInit_bz2(void)
 {
     PyObject *m;
 
-    Py_TYPE(&BZ2File_Type) = &PyType_Type;
-    Py_TYPE(&BZ2Comp_Type) = &PyType_Type;
-    Py_TYPE(&BZ2Decomp_Type) = &PyType_Type;
+    if (PyType_Ready(&BZ2File_Type) < 0)
+        return NULL;
+    if (PyType_Ready(&BZ2Comp_Type) < 0)
+        return NULL;
+    if (PyType_Ready(&BZ2Decomp_Type) < 0)
+        return NULL;
 
     m = PyModule_Create(&bz2module);
     if (m == NULL)