From d78c54accd83f2ec81b51cb30f9bdddb845c9ad4 Mon Sep 17 00:00:00 2001
From: TerryE <terry@ellisons.org.uk>
Date: Mon, 26 Mar 2018 03:44:10 +0100
Subject: [PATCH] Fix Lua stack corruption problem

---
 app/lua/ldo.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/app/lua/ldo.c b/app/lua/ldo.c
index 9a2ddd0e..fa9e9fdc 100644
--- a/app/lua/ldo.c
+++ b/app/lua/ldo.c
@@ -144,8 +144,11 @@ static void correctstack (lua_State *L, TValue *oldstack) {
 void luaD_reallocstack (lua_State *L, int newsize) {
   TValue *oldstack = L->stack;
   int realsize = newsize + 1 + EXTRA_STACK;
+  int block_status = is_block_gc(L);
   lua_assert(L->stack_last - L->stack == L->stacksize - EXTRA_STACK - 1);
+  set_block_gc(L);       /* The GC MUST be blocked during stack reallocaiton */
   luaM_reallocvector(L, L->stack, L->stacksize, realsize, TValue);
+  if (!block_status) unset_block_gc(L);  /* Honour the previous block status */
   L->stacksize = realsize;
   L->stack_last = L->stack+newsize;
   correctstack(L, oldstack);