* object.c (rb_mod_cvar_set): call to_str for string only once.

  to_str was called from rb_is_class_name and rb_to_id before.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@40174 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

3 files changed, 17 insertions, 5 deletions

diff --git a/ChangeLog b/ChangeLog
index a79d236467..60dd77f49e 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Sun Apr  7 21:16:19 2013  NARUSE, Yui  <naruse@ruby-lang.org>
+
+	* object.c (rb_mod_cvar_set): call to_str for string only once.
+	  to_str was called from rb_is_class_name and rb_to_id before.
+
 Sun Apr  7 13:56:16 2013  Kazuhiro NISHIYAMA  <zn@mbf.nifty.com>
 
 	* test/ruby/test_require.rb (TestRequire#test_require_nonascii_path):
diff --git a/object.c b/object.c
index 355a7569e5..81f7893a21 100644
--- a/object.c
+++ b/object.c
@@ -2305,12 +2305,17 @@ rb_mod_cvar_set(VALUE obj, VALUE iv, VALUE val)
 			  QUOTE_ID(id));
 	}
     }
-    else if (!rb_is_class_name(iv)) {
-	rb_name_error_str(iv, "`%"PRIsVALUE"' is not allowed as a class variable name",
-			  QUOTE(iv));
-    }
     else {
-	id = rb_to_id(iv);
+	VALUE cname = rb_check_string_type(iv);
+	if (NIL_P(cname)) {
+	    rb_raise(rb_eTypeError, "%+"PRIsVALUE" is not a symbol or string",
+		     iv);
+	}
+	if (!rb_is_class_name(cname)) {
+	    rb_name_error_str(iv, "`%"PRIsVALUE"' is not allowed as a class variable name",
+		    QUOTE(cname));
+	}
+	id = rb_to_id(cname);
     }
     rb_cvar_set(obj, id, val);
     return val;
diff --git a/test/ruby/test_module.rb b/test/ruby/test_module.rb
index b11a86a4da..c899948128 100644
--- a/test/ruby/test_module.rb
+++ b/test/ruby/test_module.rb
@@ -665,6 +665,7 @@ class TestModule < Test::Unit::TestCase
     c.class_eval('@@foo = :foo')
     assert_equal(:foo, c.class_variable_get(:@@foo))
     assert_raise(NameError) { c.class_variable_get(:@@bar) } # c.f. instance_variable_get
+    assert_raise(NameError) { c.class_variable_get('@@') }
     assert_raise(NameError) { c.class_variable_get(:foo) }
     assert_raise(NameError) { c.class_variable_get("bar") }
     assert_raise(TypeError) { c.class_variable_get(1) }
@@ -674,6 +675,7 @@ class TestModule < Test::Unit::TestCase
     c = Class.new
     c.class_variable_set(:@@foo, :foo)
     assert_equal(:foo, c.class_eval('@@foo'))
+    assert_raise(NameError) { c.class_variable_set('@@', 1) }
     assert_raise(NameError) { c.class_variable_set(:foo, 1) }
     assert_raise(NameError) { c.class_variable_set("bar", 1) }
     assert_raise(TypeError) { c.class_variable_set(1, 1) }