From 9d777346bc4e3b033dd78393980d41ee7bc34867 Mon Sep 17 00:00:00 2001
From: Mike Pall <mike>
Date: Mon, 13 Jan 2025 16:16:27 +0100
Subject: [PATCH] Reject negative getfenv()/setfenv() levels to prevent
 compiler warning.

Thanks to Sergey Kaplun. #1329
---
 src/lib_base.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/lib_base.c b/src/lib_base.c
index 5190f3fe..7683163c 100644
--- a/src/lib_base.c
+++ b/src/lib_base.c
@@ -141,6 +141,8 @@ LJLIB_CF(getfenv)
   cTValue *o = L->base;
   if (!(o < L->top && tvisfunc(o))) {
     int level = lj_lib_optint(L, 1, 1);
+    if (level < 0)
+      lj_err_arg(L, 1, LJ_ERR_INVLVL);
     o = lj_debug_frame(L, level, &level);
     if (o == NULL)
       lj_err_arg(L, 1, LJ_ERR_INVLVL);
@@ -162,6 +164,8 @@ LJLIB_CF(setfenv)
       setgcref(L->env, obj2gco(t));
       return 0;
     }
+    if (level < 0)
+      lj_err_arg(L, 1, LJ_ERR_INVLVL);
     o = lj_debug_frame(L, level, &level);
     if (o == NULL)
       lj_err_arg(L, 1, LJ_ERR_INVLVL);