From bdb8607cb7549f8555fed781392231ead86d984b Mon Sep 17 00:00:00 2001
From: shugo <shugo@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
Date: Sat, 8 Dec 2012 13:35:12 +0000
Subject: [PATCH] * eval.c (top_using): raise a RuntimeError if using is called
 in a   module definition or a method definition.

* test/ruby/test_refinement.rb: related test.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@38274 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
---
 ChangeLog                    |  7 +++++++
 eval.c                       |  4 ++++
 test/ruby/test_refinement.rb | 27 +++++++++++++++++++++++++++
 3 files changed, 38 insertions(+)

diff --git a/ChangeLog b/ChangeLog
index 91ca68c0b0..2364d0c2d8 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+Sat Dec  8 13:17:55 2012  Shugo Maeda  <shugo@ruby-lang.org>
+
+	* eval.c (top_using): raise a RuntimeError if using is called in a
+	  module definition or a method definition.
+
+	* test/ruby/test_refinement.rb: related test.
+
 Sat Dec  8 15:01:35 2012  Eric Hodel  <drbrain@segment7.net>
 
 	* lib/rubygems/commands/cleanup_command.rb:  Skip default gems when
diff --git a/eval.c b/eval.c
index 934037da91..d0dcdddc6b 100644
--- a/eval.c
+++ b/eval.c
@@ -1393,7 +1393,11 @@ static VALUE
 top_using(VALUE self, VALUE module)
 {
     NODE *cref = rb_vm_cref();
+    rb_control_frame_t *prev_cfp = previous_frame(GET_THREAD());
 
+    if (cref->nd_next || (prev_cfp && prev_cfp->me)) {
+	rb_raise(rb_eRuntimeError, "using is permitted only at toplevel");
+    }
     Check_Type(module, T_MODULE);
     rb_using_module(cref, module);
     rb_clear_cache();
diff --git a/test/ruby/test_refinement.rb b/test/ruby/test_refinement.rb
index 0d934d737e..016aa15f19 100644
--- a/test/ruby/test_refinement.rb
+++ b/test/ruby/test_refinement.rb
@@ -624,6 +624,33 @@ class TestRefinement < Test::Unit::TestCase
     end
   end
 
+  def test_using_in_module
+    assert_raise(RuntimeError) do
+      eval(<<-EOF, TOPLEVEL_BINDING)
+        $main = self
+        module M
+        end
+        module M2
+          $main.send(:using, M)
+        end
+      EOF
+    end
+  end
+
+  def test_using_in_method
+    assert_raise(RuntimeError) do
+      eval(<<-EOF, TOPLEVEL_BINDING)
+        $main = self
+        module M
+        end
+        def call_using_in_method
+          $main.send(:using, M)
+        end
+        call_using_in_method
+      EOF
+    end
+  end
+
   private
 
   def eval_using(mod, s)