compar.c: fail if recursion

* compar.c (cmp_eq): fail if recursion.  [ruby-core:57736] [Bug #9003]
* thread.c (rb_exec_recursive_paired_outer): new function which is
  combinnation of paired and outer variants.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@43208 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 7 insertions, 0 deletions

diff --git a/test/ruby/test_comparable.rb b/test/ruby/test_comparable.rb
index c686adeceb..747f1e29a7 100644
--- a/test/ruby/test_comparable.rb
+++ b/test/ruby/test_comparable.rb
@@ -76,4 +76,11 @@ class TestComparable < Test::Unit::TestCase
       assert_nil(Time.new <=> "")
     }
   end
+
+  def test_no_cmp
+    bug9003 = '[ruby-core:57736] [Bug #9003]'
+    assert_nothing_raised(SystemStackError, bug9003) {
+      @o <=> @o.dup
+    }
+  end
 end