Bug: Ephemeron table can wrongly collect entry with strong key

lgc.c

@@ -1,5 +1,5 @@
 /*
-** $Id: lgc.c,v 2.140.1.1 2013/04/12 18:48:47 roberto Exp roberto $
+** $Id: lgc.c,v 2.140.1.2 2013/04/26 18:22:05 roberto Exp roberto $
 ** Garbage Collector
 ** See Copyright Notice in lua.h
 */
@@ -403,7 +403,7 @@ static int traverseephemeron (global_State *g, Table *h) {
       reallymarkobject(g, gcvalue(gval(n)));  /* mark it now */
     }
   }
-  if (prop)
+  if (g->gcstate != GCSatomic || prop)
     linktable(h, &g->ephemeron);  /* have to propagate again */
   else if (hasclears)  /* does table have white keys? */
     linktable(h, &g->allweak);  /* may have to clean white keys */