class.c: preserve encoding

* class.c (rb_check_inheritable): preserve encoding in an error
  message when the superclass is not a class.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@51050 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

class.c

@@ -214,8 +214,8 @@ void
 rb_check_inheritable(VALUE super)
 {
     if (!RB_TYPE_P(super, T_CLASS)) {
-	rb_raise(rb_eTypeError, "superclass must be a Class (%s given)",
-		 rb_obj_classname(super));
+	rb_raise(rb_eTypeError, "superclass must be a Class (%"PRIsVALUE" given)",
+		 rb_obj_class(super));
     }
     if (RBASIC(super)->flags & FL_SINGLETON) {
 	rb_raise(rb_eTypeError, "can't make subclass of singleton class");

test/ruby/test_class.rb

@@ -193,6 +193,9 @@ class TestClass < Test::Unit::TestCase
     assert_raise(TypeError) { Class.new(c) }
     assert_raise(TypeError) { Class.new(Class) }
     assert_raise(TypeError) { eval("class Foo < Class; end") }
+    m = "M\u{1f5ff}"
+    o = Class.new {break eval("class #{m}; self; end.new")}
+    assert_raise_with_message(TypeError, /#{m}/) {Class.new(o)}
   end
 
   def test_initialize_copy