Index: lily/include/smobs.tcc |
diff --git a/lily/include/smobs.tcc b/lily/include/smobs.tcc |
index c0a62535f5e4f830200c8b4a249ae955032d414f..b4dacacaa325ec8759bf321e368b4c8e138cc0ff 100644 |
--- a/lily/include/smobs.tcc |
+++ b/lily/include/smobs.tcc |
@@ -32,14 +32,20 @@ template <class Super> |
SCM |
Smob_base<Super>::mark_trampoline (SCM arg) |
{ |
- return (Super::unsmob (arg))->mark_smob (); |
+ Super *ptr = Super::unsmob (arg); |
+ if (ptr) |
+ return ptr->mark_smob (); |
+ return SCM_UNDEFINED; |
} |
template <class Super> |
int |
Smob_base<Super>::print_trampoline (SCM arg, SCM port, scm_print_state *p) |
{ |
- return (Super::unsmob (arg))->print_smob (port, p); |
+ Super *ptr = Super::unsmob (arg); |
+ if (ptr) |
+ return ptr->print_smob (port, p); |
+ return 0; |
} |
template <class Super> |
@@ -96,6 +102,7 @@ Smob_base<Super>::unregister_ptr (SCM obj) |
{ |
Super *p = Super::unchecked_unsmob (obj); |
scm_gc_unregister_collectable_memory (p, sizeof (*p), smob_name_.c_str ()); |
+ SCM_SET_SMOB_DATA (obj, static_cast<Super *> (0)); |
return p; |
} |