From 4b01983bf81259e3d1837b4c8a27c440c0278403 Mon Sep 17 00:00:00 2001
From: Nobuyoshi Nakada <nobu@ruby-lang.org>
Date: Tue, 9 Jan 2024 13:05:34 +0900
Subject: [PATCH] Simplify empty hahs with DSTAR

---
 parse.y | 16 ++++------------
 1 file changed, 4 insertions(+), 12 deletions(-)

diff --git a/parse.y b/parse.y
index 2ac575ca7f..0ddf12acce 100644
--- a/parse.y
+++ b/parse.y
@@ -6858,7 +6858,9 @@ assocs		: assoc
                                     tail = RNODE_HASH(n)->nd_head;
                                 }
                             }
-                            assocs = list_concat(assocs, tail);
+                            if (tail) {
+                                assocs = list_concat(assocs, tail);
+                            }
                         }
                         $$ = assocs;
                     /*% %*/
@@ -6900,17 +6902,7 @@ assoc		: arg_value tASSOC arg_value
                 | tDSTAR arg_value
                     {
                     /*%%%*/
-                        if (nd_type_p($2, NODE_HASH) &&
-                            !(RNODE_HASH($2)->nd_head && RNODE_LIST(RNODE_HASH($2)->nd_head)->as.nd_alen)) {
-                            static VALUE empty_hash;
-                            if (!empty_hash) {
-                                empty_hash = rb_obj_freeze(rb_hash_new());
-                                rb_gc_register_mark_object(empty_hash);
-                            }
-                            $$ = list_append(p, NEW_LIST(0, &@$), NEW_LIT(empty_hash, &@$));
-                        }
-                        else
-                            $$ = list_append(p, NEW_LIST(0, &@$), $2);
+                        $$ = list_append(p, NEW_LIST(0, &@$), $2);
                     /*% %*/
                     /*% ripper: assoc_splat!($2) %*/
                     }