class.c: refine error messages

* class.c (rb_define_class, rb_define_class_id_under): refine
  error messages.
* class.c (rb_define_module, rb_define_module_id_under): ditto,
  and make consistent with class.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@51958 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 7 insertions, 0 deletions

diff --git a/test/ruby/test_class.rb b/test/ruby/test_class.rb
index 9c016dd693..1d9ee55d7a 100644
--- a/test/ruby/test_class.rb
+++ b/test/ruby/test_class.rb
@@ -547,5 +547,12 @@ class TestClass < Test::Unit::TestCase
     assert_raise_with_message(TypeError, "#{n} is not a class") {
       m.module_eval "class #{n}; end"
     }
+
+    assert_separately([], <<-"end;")
+      Date = (class C\u{1f5ff}; self; end).new
+      assert_raise_with_message(TypeError, /C\u{1f5ff}/) {
+        require 'date'
+      }
+    end;
   end
 end