In PySys_GetObject(), it's possible that tstate->interp->sysdict is

NULL.  In that case, return NULL rather than dumping core.

This fixes PR#91, submitted by Lele Gaifax.

Python/sysmodule.c

@@ -64,6 +64,8 @@ PySys_GetObject(name)
 {
 	PyThreadState *tstate = PyThreadState_Get();
 	PyObject *sd = tstate->interp->sysdict;
+	if (sd == NULL)
+		return NULL;
 	return PyDict_GetItemString(sd, name);
 }