eval.c: singleton class constants

* eval.c (rb_mod_s_constants): return its own constants for other
  than Module itself.  [ruby-core:59763] [Bug #9413]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@44628 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,8 @@
+Fri Jan 17 17:58:04 2014  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* eval.c (rb_mod_s_constants): return its own constants for other
+	  than Module itself.  [ruby-core:59763] [Bug #9413]
+
 Tue Jan 16 00:17:00 2014  Kenta Murata  <mrkn@mrkn.jp>
 
 	* ext/bigdecimal/bigdecimal.gemspec: bigdecimal version 1.2.5.

eval.c

@@ -378,8 +378,8 @@ rb_mod_s_constants(int argc, VALUE *argv, VALUE mod)
     VALUE cbase = 0;
     void *data = 0;
 
-    if (argc > 0) {
+    if (argc > 0 || mod != rb_cModule) {
-	return rb_mod_constants(argc, argv, rb_cModule);
+	return rb_mod_constants(argc, argv, mod);
     }
 
     while (cref) {

test/ruby/test_module.rb

@@ -866,6 +866,19 @@ class TestModule < Test::Unit::TestCase
     m.instance_eval { remove_const(:Foo) }
   end
 
+  class Bug9413
+    class << self
+      Foo = :foo
+    end
+  end
+
+  def test_singleton_constants
+    bug9413 = '[ruby-core:59763] [Bug #9413]'
+    c = Bug9413.singleton_class
+    assert_include(c.constants(true), :Foo, bug9413)
+    assert_include(c.constants(false), :Foo, bug9413)
+  end
+
   def test_frozen_class
     m = Module.new
     m.freeze