Issue #11321: Fix a crash with multiple imports of the _pickle module when

embedding Python.  Patch by Andreas Stührk.

Misc/NEWS

@@ -27,6 +27,9 @@ Core and Builtins
 Library
 -------
 
+- Issue #11321: Fix a crash with multiple imports of the _pickle module when
+  embedding Python.  Patch by Andreas Stührk.
+
 - Issue #12502: asyncore: fix polling loop with AF_UNIX sockets.
 
 - Issue #4376: ctypes now supports nested structures in a endian different than

Modules/_pickle.c

@@ -6321,8 +6321,10 @@ PyInit__pickle(void)
     if (m == NULL)
         return NULL;
 
+    Py_INCREF(&Pickler_Type);
     if (PyModule_AddObject(m, "Pickler", (PyObject *)&Pickler_Type) < 0)
         return NULL;
+    Py_INCREF(&Unpickler_Type);
     if (PyModule_AddObject(m, "Unpickler", (PyObject *)&Unpickler_Type) < 0)
         return NULL;