From 4bd94ccbbd60d1d5cd19de2aba08b1ef4feadc6e Mon Sep 17 00:00:00 2001
From: Jean Boussier <byroot@ruby-lang.org>
Date: Tue, 14 Jul 2026 22:35:47 +0200
Subject: [PATCH] variable.c: only filter out `object_id`, not all internal
 ivars

---
 shape.c    | 10 ++++------
 shape.h    |  1 +
 variable.c |  2 +-
 3 files changed, 6 insertions(+), 7 deletions(-)

diff --git a/shape.c b/shape.c
index 0004d4cc56..c54c86b937 100644
--- a/shape.c
+++ b/shape.c
@@ -33,8 +33,6 @@
 #define MAX_SHAPE_ID (INVALID_SHAPE_ID - 1)
 #define ANCESTOR_SEARCH_MAX_DEPTH 2
 
-static ID id_object_id;
-
 // Should be on its own cache line
 static RUBY_ALIGNAS(128) rb_atomic_t redblack_cache_size;
 
@@ -701,7 +699,7 @@ rb_shape_transition_object_id(shape_id_t original_shape_id)
     bool dont_care;
     rb_shape_t *shape = NULL;
     if (LIKELY(original_shape->next_field_index < rb_shape_max_capacity())) {
-        shape = get_next_shape_internal(original_shape, id_object_id, SHAPE_OBJ_ID, &dont_care, true);
+        shape = get_next_shape_internal(original_shape, rb_shape_tree.id_object_id, SHAPE_OBJ_ID, &dont_care, true);
     }
     if (!shape) {
         return rb_shape_layout(original_shape_id) | ROOT_COMPLEX_WITH_OBJ_ID | RSHAPE_FLAGS(original_shape_id);
@@ -1612,7 +1610,7 @@ Init_default_shapes(void)
         rb_memerror();
     }
 
-    id_object_id = rb_make_internal_id();
+    rb_shape_tree.id_object_id = rb_make_internal_id();
 
 #ifdef HAVE_MMAP
     size_t shape_cache_mmap_size = rb_size_mul_or_raise(REDBLACK_CACHE_SIZE, sizeof(redblack_node_t), rb_eRuntimeError);
@@ -1647,11 +1645,11 @@ Init_default_shapes(void)
     RUBY_ASSERT(!(SHAPE_OFFSET(root) & SHAPE_ID_HAS_IVAR_MASK));
 
     bool dontcare;
-    rb_shape_t *root_with_obj_id = get_next_shape_internal(root, id_object_id, SHAPE_OBJ_ID, &dontcare, true);
+    rb_shape_t *root_with_obj_id = get_next_shape_internal(root, rb_shape_tree.id_object_id, SHAPE_OBJ_ID, &dontcare, true);
     RUBY_ASSERT(root_with_obj_id);
     RUBY_ASSERT(SHAPE_OFFSET(root_with_obj_id) == ROOT_SHAPE_WITH_OBJ_ID);
     RUBY_ASSERT(root_with_obj_id->type == SHAPE_OBJ_ID);
-    RUBY_ASSERT(root_with_obj_id->edge_name == id_object_id);
+    RUBY_ASSERT(root_with_obj_id->edge_name == rb_shape_tree.id_object_id);
     RUBY_ASSERT(root_with_obj_id->next_field_index == 1);
     RUBY_ASSERT(!(SHAPE_OFFSET(root_with_obj_id) & SHAPE_ID_HAS_IVAR_MASK));
     (void)root_with_obj_id;
diff --git a/shape.h b/shape.h
index c2cf158c72..f885bab74f 100644
--- a/shape.h
+++ b/shape.h
@@ -134,6 +134,7 @@ enum shape_flags {
 typedef struct {
     rb_shape_t *shape_list;
     attr_index_t max_capacity;
+    ID id_object_id;
 } rb_shape_tree_t;
 
 RUBY_SYMBOL_EXPORT_BEGIN
diff --git a/variable.c b/variable.c
index 7edeb57c93..c29054b576 100644
--- a/variable.c
+++ b/variable.c
@@ -2185,7 +2185,7 @@ each_hash_iv(st_data_t id, st_data_t val, st_data_t data)
 {
     struct iv_itr_data * itr_data = (struct iv_itr_data *)data;
     rb_ivar_foreach_callback_func *callback = itr_data->func;
-    if (is_internal_id((ID)id)) {
+    if ((ID)id == rb_shape_tree.id_object_id) {
         return ST_CONTINUE;
     }
     return callback((ID)id, (VALUE)val, itr_data->arg);