Sanity check the atom register/unregister funcs

diff --git a/src/modem.c b/src/modem.c
index 285aa33..8119ea1 100644 (file)
--- a/src/modem.c
+++ b/src/modem.c
@@ -135,13 +135,18 @@ void *__ofono_atom_get_data(struct ofono_atom *atom)
 void __ofono_atom_register(struct ofono_atom *atom,
                        void (*unregister)(struct ofono_atom *))
 {
+       if (unregister == NULL)
+               return;
+
        atom->unregister = unregister;
 }
 
 void __ofono_atom_unregister(struct ofono_atom *atom)
 {
-       if (atom->unregister)
-               atom->unregister(atom);
+       if (atom->unregister == NULL)
+               return;
+               
+       atom->unregister(atom);
 }
 
 struct ofono_atom *__ofono_modem_find_atom(struct ofono_modem *modem,