merge revision(s) 2e7e78c: [Backport #21440]

	[Bug #21440] Stop caching member list in frozen Data/Struct class

Author: k0kubun

struct.c

@@ -52,7 +52,8 @@ struct_ivar_get(VALUE c, ID id)
         RUBY_ASSERT(RB_TYPE_P(c, T_CLASS));
         ivar = rb_attr_get(c, id);
         if (!NIL_P(ivar)) {
-            return rb_ivar_set(orig, id, ivar);
+            if (!OBJ_FROZEN(orig)) rb_ivar_set(orig, id, ivar);
+            return ivar;
         }
     }
 }

test/ruby/test_data.rb

@@ -280,4 +280,10 @@ def test_marshal
     assert_not_same(test, loaded)
     assert_predicate(loaded, :frozen?)
   end
+
+  def test_frozen_subclass
+    test = Class.new(Data.define(:a)).freeze.new(a: 0)
+    assert_kind_of(Data, test)
+    assert_equal([:a], test.members)
+  end
 end

test/ruby/test_struct.rb

@@ -548,6 +548,12 @@ def test_named_structs_are_not_rooted
     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
 

version.h

@@ -11,7 +11,7 @@
 # define RUBY_VERSION_MINOR RUBY_API_VERSION_MINOR
 #define RUBY_VERSION_TEENY 4
 #define RUBY_RELEASE_DATE RUBY_RELEASE_YEAR_STR"-"RUBY_RELEASE_MONTH_STR"-"RUBY_RELEASE_DAY_STR
-#define RUBY_PATCHLEVEL 47
+#define RUBY_PATCHLEVEL 48
 
 #include "ruby/version.h"
 #include "ruby/internal/abi.h"