From 615838a7d4edf7971f529dcdcdd6af600f2bd0ad Mon Sep 17 00:00:00 2001
From: Andrew Tridgell <andrew@tridgell.net>
Date: Thu, 9 Mar 2023 10:39:37 +1100
Subject: [PATCH] AP_Scripting: ensure new user data is zero

this prevents use of uninitialised data for user objects created in
lua, giving more predictable behaviour
---
 libraries/AP_Scripting/lua/src/lapi.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/libraries/AP_Scripting/lua/src/lapi.c b/libraries/AP_Scripting/lua/src/lapi.c
index 02b7fab7ea..b8cf086fc8 100644
--- a/libraries/AP_Scripting/lua/src/lapi.c
+++ b/libraries/AP_Scripting/lua/src/lapi.c
@@ -1189,7 +1189,9 @@ LUA_API void *lua_newuserdata (lua_State *L, size_t size) {
   api_incr_top(L);
   luaC_checkGC(L);
   lua_unlock(L);
-  return getudatamem(u);
+  void *udata = getudatamem(u);
+  memset(udata, 0, size);
+  return udata;
 }