1 files changed, 8 insertions, 6 deletions

diff --git a/lfunc.c b/lfunc.c
index 9f91ad4f..f7edf56b 100644
--- a/lfunc.c
+++ b/lfunc.c
@@ -82,20 +82,22 @@ static UpVal *newupval (lua_State *L, int tbc, StkId level, UpVal **prev) {
 
 
 /*
-** Find and reuse, or create if it does not exist, a regular upvalue
-** at the given level.
+** Find and reuse, or create if it does not exist, an upvalue
+** at the given level and set it to the given slot.
 */
-UpVal *luaF_findupval (lua_State *L, StkId level) {
+void luaF_setupval (lua_State *L, StkId level, UpVal **slot) {
   UpVal **pp = &L->openupval;
   UpVal *p;
   lua_assert(isintwups(L) || L->openupval == NULL);
   while ((p = *pp) != NULL && uplevel(p) >= level) {  /* search for it */
+    *slot = p;
     if (uplevel(p) == level && !isdead(G(L), p))  /* corresponding upvalue? */
-      return p;  /* return it */
+      return;  /* found it */
     pp = &p->u.open.next;
   }
-  /* not found: create a new upvalue after 'pp' */
-  return newupval(L, 0, level, pp);
+  /* not found: create a new upvalue after 'pp' (which is
+    anchored in 'slot', in case of an emergency collection) */
+  *slot = newupval(L, 0, level, pp);
 }