get rid of references to freed code.

C/cdmgr.c

@@ -1258,6 +1258,8 @@ cleanup_dangling_indices(yamop *ipc, yamop *beg, yamop *end, yamop *suspend_code
     case _switch_on_cons:
     case _if_cons:
     case _go_on_cons:
+      /* make sure we don't leave dangling references to memory that is going to be removed */
+      ipc->u.sssl.l = NULL;
       ipc = NEXTOP(ipc,sssl);
       break;
     case _op_fail:
@@ -1272,12 +1274,6 @@ cleanup_dangling_indices(yamop *ipc, yamop *beg, yamop *end, yamop *suspend_code
   }
 }
 
-void
-Yap_cleanup_dangling_indices(yamop *ipc, yamop *beg, yamop *end, yamop *sc)
-{
-  cleanup_dangling_indices(ipc, beg, end, sc);
-}
-
 static void
 decrease_log_indices(LogUpdIndex *c, yamop *suspend_code)
 {

H/clause.h

@@ -205,7 +205,6 @@ void	STD_PROTO(Yap_IPred,(PredEntry *, UInt, yamop *));
 int	STD_PROTO(Yap_addclause,(Term,yamop *,int,Term,Term*));
 void	STD_PROTO(Yap_add_logupd_clause,(PredEntry *,LogUpdClause *,int));
 void	STD_PROTO(Yap_kill_iblock,(ClauseUnion *,ClauseUnion *,PredEntry *));
-void	STD_PROTO(Yap_cleanup_dangling_indices,(yamop *,yamop *,yamop *,yamop *));
 void	STD_PROTO(Yap_EraseStaticClause,(StaticClause *, Term));
 ClauseUnion *STD_PROTO(Yap_find_owner_index,(yamop *, PredEntry *));
 

H/rheap.h

@@ -284,6 +284,9 @@ static void
 AdjustSwitchTable(op_numbers op, yamop *table, COUNT i)
 {
   CELL *startcode = (CELL *)table;
+  /* in case the table is already gone */
+  if (!table)
+    return;
   switch (op) {
   case _switch_on_func:
     {