1 files changed, 29 insertions, 1 deletions
diff --git a/test/ruby/test_struct.rb b/test/ruby/test_struct.rb
index ed750b91f7..b37f4dba97 100644
--- a/test/ruby/test_struct.rb
+++ b/test/ruby/test_struct.rb
@@ -41,8 +41,14 @@ module TestStruct
     end
   end
 
+  MAX_EMBEDDED_MEMBERS = (
+    GC::INTERNAL_CONSTANTS[:RVARGC_MAX_ALLOCATE_SIZE] -
+    GC::INTERNAL_CONSTANTS[:RBASIC_SIZE] -
+    GC::INTERNAL_CONSTANTS[:RVALUE_OVERHEAD]
+  ) / RbConfig::SIZEOF["void*"]
+
   def test_larger_than_largest_pool
-    count = (GC::INTERNAL_CONSTANTS[:RVARGC_MAX_ALLOCATE_SIZE] / RbConfig::SIZEOF["void*"]) + 1
+    count = MAX_EMBEDDED_MEMBERS + 1
     list = Array(0..count)
     klass = @Struct.new(*list.map { |i| :"a_#{i}"})
     struct = klass.new(*list)
@@ -534,6 +540,28 @@ module TestStruct
     assert_equal [[:req, :_]], klass.instance_method(:c=).parameters
   end
 
+  def test_named_structs_are_not_rooted
+    omit 'skip on riscv64-linux CI machine. See https://github.com/ruby/ruby/pull/13422' if ENV['RUBY_DEBUG'] == 'ci' && /riscv64-linux/ =~ RUBY_DESCRIPTION
+
+    # [Bug #20311]
+    assert_no_memory_leak([], <<~PREP, <<~CODE, rss: true, limit: 2.2)
+      code = proc do
+        Struct.new("A")
+        Struct.send(:remove_const, :A)
+      end
+
+      10_000.times(&code)
+    PREP
+      50_000.times(&code)
+    CODE
+  end
+
+  def test_frozen_subclass
+    test = Class.new(@Struct.new(:a)).freeze.new(a: 0)
+    assert_kind_of(@Struct, test)
+    assert_equal([:a], test.members)
+  end
+
   class TopStruct < Test::Unit::TestCase
     include TestStruct