Fix for last commit

src/lj_api.c

@@ -1164,7 +1164,7 @@ LUA_API int lua_gc(lua_State *L, int what, int data)
     MSize a = (MSize)data << 10;
     g->gc.threshold = (a <= g->gc.total) ? (g->gc.total - a) : 0;
     while (g->gc.total >= g->gc.threshold)
-      if (lj_gc_step(L)) {
+      if (lj_gc_step(L) > 0) {
 	res = 1;
 	break;
       }

src/lj_gc.c

@@ -690,7 +690,7 @@ int LJ_FASTCALL lj_gc_step(lua_State *L)
   if (g->gc.debt < GCSTEPSIZE) {
     g->gc.threshold = g->gc.total + GCSTEPSIZE;
     g->vmstate = ostate;
-    return 1;
+    return -1;
   } else {
     g->gc.debt -= GCSTEPSIZE;
     g->gc.threshold = g->gc.total;