Issue #19536 has been reported by peterzhu2118 (Peter Zhu). ---------------------------------------- Bug #19536: Frozen status loss when moving objects https://bugs.ruby-lang.org/issues/19536 * Author: peterzhu2118 (Peter Zhu) * Status: Open * Priority: Normal * Backport: 2.7: DONTNEED, 3.0: DONTNEED, 3.1: DONTNEED, 3.2: REQUIRED ---------------------------------------- GitHub PR: https://github.com/ruby/ruby/pull/7553 When objects are moved between size pools, their frozen status is lost in the shape. This will cause the frozen check to be bypassed when there is an inline cache. For example, the following script should raise a FrozenError, but doesn't on Ruby 3.2 and master. ```ruby class A def add_ivars @a = @b = @c = @d = 1 end def set_a @a = 10 end end a = A.new a.add_ivars a.freeze b = A.new b.add_ivars b.set_a # Set the inline cache in set_a GC.verify_compaction_references(expand_heap: true, toward: :empty) a.set_a ``` -- https://bugs.ruby-lang.org/