1 files changed, 14 insertions, 1 deletions
diff --git a/activesupport/lib/active_support/core_ext/object/duplicable.rb b/activesupport/lib/active_support/core_ext/object/duplicable.rb
index 9cd7485e2e..665cb0f96d 100644
--- a/activesupport/lib/active_support/core_ext/object/duplicable.rb
+++ b/activesupport/lib/active_support/core_ext/object/duplicable.rb
@@ -19,7 +19,7 @@
 class Object
   # Can you safely dup this object?
   #
-  # False for +nil+, +false+, +true+, symbol, and number objects;
+  # False for +nil+, +false+, +true+, symbol, number and BigDecimal(in 1.9.x) objects;
   # true otherwise.
   def duplicable?
     true
@@ -78,6 +78,9 @@ end
 
 require 'bigdecimal'
 class BigDecimal
+  # Needed to support Ruby 1.9.x, as it doesn't allow dup on BigDecimal, instead
+  # raises TypeError exception. Checking here on the runtime whether BigDecimal
+  # will allow dup or not.
   begin
     BigDecimal.new('4.56').dup
 
@@ -88,3 +91,13 @@ class BigDecimal
     # can't dup, so use superclass implementation
   end
 end
+
+class Method
+  # Methods are not duplicable:
+  #
+  #  method(:puts).duplicable? # => false
+  #  method(:puts).dup         # => TypeError: allocator undefined for Method
+  def duplicable?
+    false
+  end
+end