merges r20866 and r20968 from trunk into ruby_1_9_1.

* error.c (exc_equal): duck typing equal to make it transitive.
  [ruby-dev:34880]
--
* error.c (exc_equal): == method should not raise Exception.
  [ruby-dev:37519]

* sample/test.rb: fix test

git-svn-id: http://svn.ruby-lang.org/repos/ruby/branches/ruby_1_9_1@21025 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 5 insertions, 3 deletions

diff --git a/sample/test.rb b/sample/test.rb
index 34e96204a..21656885f 100644
--- a/sample/test.rb
+++ b/sample/test.rb
@@ -660,10 +660,12 @@ begin
     raise $string
   end
   test_ok(false)
-rescue
-  test_ok(true) if $! == $string
+rescue => e
+  test_ok($! == e)
+  test_ok(e.message == $string)
+  test_ok(e != $string)
 end
-  
+
 # exception in ensure clause
 begin
   begin