4 files changed, 15 insertions, 12 deletions
diff --git a/activerecord/lib/active_record.rb b/activerecord/lib/active_record.rb
index 8379f6a66f..0777f85869 100644
--- a/activerecord/lib/active_record.rb
+++ b/activerecord/lib/active_record.rb
@@ -1,5 +1,5 @@
 #--
-# Copyright (c) 2004-2010 David Heinemeier Hansson
+# Copyright (c) 2004-2011 David Heinemeier Hansson
 #
 # Permission is hereby granted, free of charge, to any person obtaining
 # a copy of this software and associated documentation files (the
diff --git a/activerecord/lib/active_record/named_scope.rb b/activerecord/lib/active_record/named_scope.rb
index 0f421560f0..d291632260 100644
--- a/activerecord/lib/active_record/named_scope.rb
+++ b/activerecord/lib/active_record/named_scope.rb
@@ -102,10 +102,9 @@ module ActiveRecord
       def scope(name, scope_options = {})
         name = name.to_sym
         valid_scope_name?(name)
-
         extension = Module.new(&Proc.new) if block_given?
 
-        scopes[name] = lambda do |*args|
+        scope_proc = lambda do |*args|
           options = scope_options.respond_to?(:call) ? scope_options.call(*args) : scope_options
 
           relation = if options.is_a?(Hash)
@@ -119,6 +118,8 @@ module ActiveRecord
           extension ? relation.extending(extension) : relation
         end
 
+        self.scopes = self.scopes.merge name => scope_proc
+
         singleton_class.send(:redefine_method, name, &scopes[name])
       end
 
diff --git a/activerecord/lib/active_record/observer.rb b/activerecord/lib/active_record/observer.rb
index 8b011ad9af..0893d7e337 100644
--- a/activerecord/lib/active_record/observer.rb
+++ b/activerecord/lib/active_record/observer.rb
@@ -104,10 +104,17 @@ module ActiveRecord
 
       def define_callbacks(klass)
         observer = self
+        observer_name = observer.class.name.underscore.gsub('/', '__')
 
         ActiveRecord::Callbacks::CALLBACKS.each do |callback|
           next unless respond_to?(callback)
-          klass.send(callback){|record| observer.send(callback, record)}
+          callback_meth = :"_notify_#{observer_name}_for_#{callback}"
+          unless klass.respond_to?(callback_meth)
+            klass.send(:define_method, callback_meth) do
+              observer.send(callback, self)
+            end
+            klass.send(callback, callback_meth)
+          end
         end
       end
   end
diff --git a/activerecord/lib/active_record/relation.rb b/activerecord/lib/active_record/relation.rb
index c6cd8891e3..3c7533ea48 100644
--- a/activerecord/lib/active_record/relation.rb
+++ b/activerecord/lib/active_record/relation.rb
@@ -67,15 +67,10 @@ module ActiveRecord
     end
 
     def respond_to?(method, include_private = false)
-      return true if arel.respond_to?(method, include_private) || Array.method_defined?(method) || @klass.respond_to?(method, include_private)
-
-      if match = DynamicFinderMatch.match(method)
-        return true if @klass.send(:all_attributes_exists?, match.attribute_names)
-      elsif match = DynamicScopeMatch.match(method)
-        return true if @klass.send(:all_attributes_exists?, match.attribute_names)
-      else
+      arel.respond_to?(method, include_private)     ||
+        Array.method_defined?(method)               ||
+        @klass.respond_to?(method, include_private) ||
         super
-      end
     end
 
     def to_a