Inspect errno only after failure

Index: lua-5.4.6/src/lauxlib.c
===================================================================
--- lua-5.4.6.orig/src/lauxlib.c
+++ lua-5.4.6/src/lauxlib.c
@@ -283,7 +283,7 @@ LUALIB_API int luaL_fileresult (lua_Stat
 
 
 LUALIB_API int luaL_execresult (lua_State *L, int stat) {
-  if (stat != 0 && errno != 0)  /* error with an 'errno'? */
+  if (stat == -1)  /* error with an 'errno'? */
     return luaL_fileresult(L, 0, NULL);
   else {
     const char *what = "exit";  /* type of termination */