Fixed bug that makes named_scopes _forgot_ current scope

activerecord/lib/active_record/named_scope.rb

@@ -100,7 +100,7 @@ def named_scope(name, options = {}, &block)
     end
     
     class Scope
-      attr_reader :proxy_scope, :proxy_options
+      attr_reader :proxy_scope, :proxy_options, :current_scoped_methods_when_defined
       NON_DELEGATE_METHODS = %w(nil? send object_id class extend find size count sum average maximum minimum paginate first last empty? any? respond_to?).to_set
       [].methods.each do |m|
         unless m =~ /^__/ || NON_DELEGATE_METHODS.include?(m.to_s)
@@ -113,6 +113,9 @@ class Scope
       def initialize(proxy_scope, options, &block)
         [options[:extend]].flatten.each { |extension| extend extension } if options[:extend]
         extend Module.new(&block) if block_given?
+        unless Scope === proxy_scope
+          @current_scoped_methods_when_defined = proxy_scope.send(:current_scoped_methods)
+        end
         @proxy_scope, @proxy_options = proxy_scope, options.except(:extend)
       end
 
@@ -168,8 +171,14 @@ def method_missing(method, *args, &block)
         else
           with_scope :find => proxy_options, :create => proxy_options[:conditions].is_a?(Hash) ?  proxy_options[:conditions] : {} do
             method = :new if method == :build
+            if current_scoped_methods_when_defined
+              with_scope current_scoped_methods_when_defined do
                 proxy_scope.send(method, *args, &block)
               end
+            else
+              proxy_scope.send(method, *args, &block)
+            end
+          end
         end
       end
 

activerecord/test/cases/named_scope_test.rb

@@ -142,6 +142,15 @@ def test_has_many_through_associations_have_access_to_named_scopes
     assert_equal authors(:david).comments & Comment.containing_the_letter_e, authors(:david).comments.containing_the_letter_e
   end
 
+  def test_named_scopes_honor_current_scopes_from_when_defined
+    assert !Post.ranked_by_comments.limit(5).empty?
+    assert !authors(:david).posts.ranked_by_comments.limit(5).empty?
+    assert_not_equal Post.ranked_by_comments.limit(5), authors(:david).posts.ranked_by_comments.limit(5)
+    assert_not_equal Post.top(5), authors(:david).posts.top(5)
+    assert_equal authors(:david).posts.ranked_by_comments.limit(5), authors(:david).posts.top(5)
+    assert_equal Post.ranked_by_comments.limit(5), Post.top(5)
+  end
+
   def test_active_records_have_scope_named__all__
     assert !Topic.find(:all).empty?
 

activerecord/test/models/post.rb

 class Post < ActiveRecord::Base
   named_scope :containing_the_letter_a, :conditions => "body LIKE '%a%'"
+  named_scope :ranked_by_comments, :order => "comments_count DESC"
+  named_scope :limit, lambda {|limit| {:limit => limit} }
   named_scope :with_authors_at_address, lambda { |address| {
       :conditions => [ 'authors.author_address_id = ?', address.id ],
       :joins => 'JOIN authors ON authors.id = posts.author_id'
@@ -68,6 +70,10 @@ def add_joins_and_select
               :before_remove => lambda {|owner, reader| log(:removed, :before, reader.first_name) },
               :after_remove  => lambda {|owner, reader| log(:removed, :after,  reader.first_name) }
 
+  def self.top(limit)
+    ranked_by_comments.limit(limit)
+  end
+
   def self.reset_log
     @log = []
   end