diff -up lua-5.4.0/src/lundump.c.bug3 lua-5.4.0/src/lundump.c
--- lua-5.4.0/src/lundump.c.bug3 2020-07-31 10:43:45.954150092 -0400
+++ lua-5.4.0/src/lundump.c 2020-07-31 10:44:31.560159336 -0400
@@ -205,8 +205,9 @@ static void loadUpvalues (LoadState *S,
n = loadInt(S);
f->upvalues = luaM_newvectorchecked(S->L, n, Upvaldesc);
f->sizeupvalues = n;
- for (i = 0; i < n; i++) {
+ for (i = 0; i < n; i++)
f->upvalues[i].name = NULL;
+ for (i = 0; i < n; i++) {
f->upvalues[i].instack = loadByte(S);
f->upvalues[i].idx = loadByte(S);
f->upvalues[i].kind = loadByte(S);