rb_copy_generic_ivar: reset shape_id when no ivar are present

Author: byroot

object.c

@@ -409,10 +409,12 @@ init_copy(VALUE dest, VALUE obj)
     RBASIC(dest)->flags &= ~(T_MASK|FL_EXIVAR);
     // Copies the shape id from obj to dest
     RBASIC(dest)->flags |= RBASIC(obj)->flags & (T_MASK|FL_EXIVAR);
-    rb_copy_generic_ivar(dest, obj);
     if (RB_TYPE_P(obj, T_OBJECT)) {
         rb_obj_copy_ivar(dest, obj);
     }
+    else {
+        rb_copy_generic_ivar(dest, obj);
+    }
     rb_gc_copy_attributes(dest, obj);
 }
 

variable.c

@@ -2438,6 +2438,9 @@ rb_copy_generic_ivar(VALUE dest, VALUE obj)
 
   clear:
     if (FL_TEST(dest, FL_EXIVAR)) {
+#if SHAPE_IN_BASIC_FLAGS
+        RBASIC_SET_SHAPE_ID(dest, ROOT_SHAPE_ID);
+#endif
         rb_free_generic_ivar(dest);
         FL_UNSET(dest, FL_EXIVAR);
     }