error.c: preserve encoding

* error.c (rb_error_frozen_object): preserve encoding of class
  name in error message.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@47634 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

error.c

@@ -2129,6 +2129,13 @@ rb_error_frozen(const char *what)
     rb_raise(rb_eRuntimeError, "can't modify frozen %s", what);
 }
 
+void
+rb_error_frozen_object(VALUE frozen_obj)
+{
+    rb_raise(rb_eRuntimeError, "can't modify frozen %"PRIsVALUE,
+	     CLASS_OF(frozen_obj));
+}
+
 #undef rb_check_frozen
 void
 rb_check_frozen(VALUE obj)

include/ruby/intern.h

@@ -255,13 +255,14 @@ PRINTF_ARGS(void rb_compile_error(const char*, int, const char*, ...), 3, 4);
 PRINTF_ARGS(void rb_compile_error_with_enc(const char*, int, void *, const char*, ...), 4, 5);
 PRINTF_ARGS(void rb_compile_error_append(const char*, ...), 1, 2);
 NORETURN(void rb_error_frozen(const char*));
+NORETURN(void rb_error_frozen_object(VALUE));
 void rb_error_untrusted(VALUE);
 void rb_check_frozen(VALUE);
 void rb_check_trusted(VALUE);
 #define rb_check_frozen_internal(obj) do { \
 	VALUE frozen_obj = (obj); \
 	if (OBJ_FROZEN(frozen_obj)) { \
-	    rb_error_frozen(rb_obj_classname(frozen_obj)); \
+	    rb_error_frozen_object(frozen_obj); \
 	} \
     } while (0)
 #define rb_check_trusted_internal(obj) ((void) 0)

test/ruby/test_object.rb

@@ -68,6 +68,17 @@ class TestObject < Test::Unit::TestCase
     assert_equal(true, nil.frozen?)
   end
 
+  def test_frozen_error_message
+    name = "C\u{30c6 30b9 30c8}"
+    klass = EnvUtil.labeled_class(name) {
+      attr_accessor :foo
+    }
+    obj = klass.new.freeze
+    assert_raise_with_message(RuntimeError, /#{name}/) {
+      obj.foo = 1
+    }
+  end
+
   def test_nil_to_f
     assert_equal(0.0, nil.to_f)
   end