Finalizers must be callable

Non-function __gc metamethods are not ignored; if present, the
metamethod will be called even if it is not a function.

1 files changed, 1 insertions, 1 deletions

diff --git a/lgc.c b/lgc.c
index c834319b..8cb3e9fa 100644
--- a/lgc.c
+++ b/lgc.c
@@ -832,7 +832,7 @@ static void GCTM (lua_State *L) {
   lua_assert(!g->gcemergency);
   setgcovalue(L, &v, udata2finalize(g));
   tm = luaT_gettmbyobj(L, &v, TM_GC);
-  if (ttisfunction(tm)) {  /* is the finalizer a function? */
+  if (!notm(tm)) {  /* is there a finalizer? */
     int status;
     lu_byte oldah = L->allowhook;
     int running  = g->gcrunning;