From d15ddf04ec6fb0cd6d350ba57d9981ebee3eddd0 Mon Sep 17 00:00:00 2001
From: Bryan Helmkamp <bryan@brynary.com>
Date: Mon, 10 Aug 2009 18:34:24 -0400
Subject: Allow delegating to nil, because the method might actually exist on
 it

---
 .../lib/active_support/core_ext/module/delegation.rb        | 13 +++++++++----
 activesupport/test/core_ext/module_test.rb                  | 13 ++++++++++++-
 2 files changed, 21 insertions(+), 5 deletions(-)

diff --git a/activesupport/lib/active_support/core_ext/module/delegation.rb b/activesupport/lib/active_support/core_ext/module/delegation.rb
index 11e01437aa..df8aefea5a 100644
--- a/activesupport/lib/active_support/core_ext/module/delegation.rb
+++ b/activesupport/lib/active_support/core_ext/module/delegation.rb
@@ -120,10 +120,15 @@ class Module
         end
 
       module_eval(<<-EOS, file, line)
-        def #{prefix}#{method}(*args, &block)                           # def customer_name(*args, &block)
-          #{on_nil} if #{to}.nil?
-          #{to}.__send__(#{method.inspect}, *args, &block)  #   client && client.__send__(:name, *args, &block)
-        end                                                             # end
+        def #{prefix}#{method}(*args, &block)               # def customer_name(*args, &block)
+          #{to}.__send__(#{method.inspect}, *args, &block)  #   client.__send__(:name, *args, &block)
+        rescue NoMethodError                                # rescue NoMethodError
+          if #{to}.nil?                                     #   if client.nil?
+            #{on_nil}
+          else                                              #   else
+            raise                                           #     raise
+          end                                               #   end
+        end                                                 # end
       EOS
     end
   end
diff --git a/activesupport/test/core_ext/module_test.rb b/activesupport/test/core_ext/module_test.rb
index f8387ae4ab..87f056ea85 100644
--- a/activesupport/test/core_ext/module_test.rb
+++ b/activesupport/test/core_ext/module_test.rb
@@ -32,7 +32,7 @@ end
 Somewhere = Struct.new(:street, :city)
 
 Someone   = Struct.new(:name, :place) do
-  delegate :street, :city, :to => :place
+  delegate :street, :city, :to_f, :to => :place
   delegate :state, :to => :@place
   delegate :upcase, :to => "place.city"
 end
@@ -44,6 +44,7 @@ end
 
 Project   = Struct.new(:description, :person) do
   delegate :name, :to => :person, :allow_nil => true
+  delegate :to_f, :to => :description, :allow_nil => true
 end
 
 class Name
@@ -145,6 +146,16 @@ class ModuleTest < Test::Unit::TestCase
     assert_raise(RuntimeError) { david.street }
   end
 
+  def test_delegation_to_method_that_exists_on_nil
+    nil_person = Someone.new(nil)
+    assert_equal 0.0, nil_person.to_f
+  end
+
+  def test_delegation_to_method_that_exists_on_nil_when_allowing_nil
+    nil_project = Project.new(nil)
+    assert_equal 0.0, nil_project.to_f
+  end
+
   def test_parent
     assert_equal Yz::Zy, Yz::Zy::Cd.parent
     assert_equal Yz, Yz::Zy.parent
-- 
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