From 7d4828cc9fdc982ec713922777e77240892474e8 Mon Sep 17 00:00:00 2001
From: Roberto Ierusalimschy <roberto@inf.puc-rio.br>
Date: Mon, 13 Nov 2017 10:26:30 -0200
Subject: [PATCH] avoid accessing wrong union field

---
 ldo.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/ldo.c b/ldo.c
index efdcbc1b..86e77f97 100644
--- a/ldo.c
+++ b/ldo.c
@@ -1,5 +1,5 @@
 /*
-** $Id: ldo.c,v 2.165 2017/11/02 11:28:56 roberto Exp $
+** $Id: ldo.c,v 2.170 2017/11/07 13:25:26 roberto Exp roberto $
 ** Stack and Call structure of Lua
 ** See Copyright Notice in lua.h
 */
@@ -365,7 +365,8 @@ int luaD_poscall (lua_State *L, CallInfo *ci, StkId firstResult, int nres) {
       luaD_hook(L, LUA_HOOKRET, -1);
       firstResult = restorestack(L, fr);
     }
-    L->oldpc = ci->previous->u.l.savedpc;  /* 'oldpc' for caller function */
+    if (isLua(ci->previous))
+      L->oldpc = ci->previous->u.l.savedpc;
   }
   res = ci->func;  /* res == final position of 1st result */
   L->ci = ci->previous;  /* back to caller */