[ruby-core:26131] [Bug #2221] lib/delegate: freeze has odd effects

Issue #2221 has been updated by Marc-Andre Lafortune.


Hi,

On Fri, Oct 16, 2009 at 7:24 AM, Yukihiro Matsumoto <[e-mail]> wrote:
> I think both should be frozen.  I checked in the patch.  I'd like to
> see if it works (or not).

Indeed, I thought about it and came to the same conclusion when thinking of other non-trivial classes that would extend Delegate. It was too cold outside my bed though :-)

(a) Just to be sure: SimpleDelegator([1,2,3].freeze).frozen? should return false, right?

(b) Still can't clone it, though.
Is there a nice way to avoid the exception? The best I can think of is the inelegant:

diff --git a/lib/delegate.rb b/lib/delegate.rb
index 5d25632..5ef9c1c 100644
--- a/lib/delegate.rb
+++ b/lib/delegate.rb
@@ -188,11 +188,14 @@ class Delegator
     __setobj__(obj)
   end
 
+  alias_method :__original_dup__, :dup
+  private :__original_dup__
+
   # Clone support for the object returned by \_\_getobj\_\_.
   def clone
-    new = super
+    new = frozen? ? __original_dup__ : super
     new.__setobj__(__getobj__.clone)
-    new
+    frozen? ? new.freeze : new
   end
   # Duplication support for the object returned by \_\_getobj\_\_.
   def dup

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