From f2e4464407cbd63a6d8861d7a695cde01409e81b Mon Sep 17 00:00:00 2001
From: Timothy N. Tsvetkov <timothy.tsvetkov@gmail.com>
Date: Mon, 21 Mar 2011 16:44:18 +0300
Subject: [PATCH] Fixes ticket #6290: Except doesn't work in different scopes.

---
 activerecord/lib/active_record/relation.rb         |    5 +++-
 .../lib/active_record/relation/spawn_methods.rb    |    6 +++++
 activerecord/test/cases/relation_scoping_test.rb   |   21 ++++++++++++++++++++
 activerecord/test/models/developer.rb              |    5 ++++
 4 files changed, 36 insertions(+), 1 deletions(-)

diff --git a/activerecord/lib/active_record/relation.rb b/activerecord/lib/active_record/relation.rb
index 371403f..baf229b 100644
--- a/activerecord/lib/active_record/relation.rb
+++ b/activerecord/lib/active_record/relation.rb
@@ -15,14 +15,17 @@ module ActiveRecord
     delegate :table_name, :primary_key, :to => :klass
 
     attr_reader :table, :klass, :loaded
-    attr_accessor :extensions
+    attr_accessor :extensions, :is_except, :skips
     alias :loaded? :loaded
+    alias :is_except? :is_except
 
     def initialize(klass, table)
       @klass, @table = klass, table
 
       @implicit_readonly = nil
       @loaded            = false
+      @is_except         = false
+      @skips             = []
 
       SINGLE_VALUE_METHODS.each {|v| instance_variable_set(:"@#{v}_value", nil)}
       (ASSOCIATION_METHODS + MULTI_VALUE_METHODS).each {|v| instance_variable_set(:"@#{v}_values", [])}
diff --git a/activerecord/lib/active_record/relation/spawn_methods.rb b/activerecord/lib/active_record/relation/spawn_methods.rb
index 4150e36..686e5cd 100644
--- a/activerecord/lib/active_record/relation/spawn_methods.rb
+++ b/activerecord/lib/active_record/relation/spawn_methods.rb
@@ -7,6 +7,9 @@ module ActiveRecord
       return to_a & r if r.is_a?(Array)
 
       merged_relation = clone
+      merged_relation.is_except = false
+
+      merged_relation = self.except(*r.skips) if r.is_except?
 
       Relation::ASSOCIATION_METHODS.each do |method|
         value = r.send(:"#{method}_values")
@@ -79,6 +82,9 @@ module ActiveRecord
         result.send(:"#{method}_value=", send(:"#{method}_value"))
       end
 
+      result.is_except = true
+      result.skips = skips
+
       result
     end
 
diff --git a/activerecord/test/cases/relation_scoping_test.rb b/activerecord/test/cases/relation_scoping_test.rb
index cda2850..976f26d 100644
--- a/activerecord/test/cases/relation_scoping_test.rb
+++ b/activerecord/test/cases/relation_scoping_test.rb
@@ -143,6 +143,27 @@ class RelationScopingTest < ActiveRecord::TestCase
 
     assert_equal scoped_methods, Developer.send(:current_scoped_methods)
   end
+
+  def test_except_in_scope_overrides_order_from_other_scope
+    expected = Developer.order('name DESC').collect { |dev| dev.name }
+    received = Developer.by_salary.reorder_by_name.collect { |dev| dev.name }
+    assert_equal expected, received
+  end
+
+  def test_except_in_scope_overrides_order_from_other_scope_with_lambda
+    expected = Developer.order('name DESC').collect { |dev| dev.name }
+    received = Developer.by_salary_with_lambda.reorder_by_name.collect { |dev| dev.name }
+    assert_equal expected, received
+
+    received = Developer.by_salary.reorder_by_name_with_lambda.collect { |dev| dev.name }
+    assert_equal expected, received
+  end
+
+  def test_except_in_scope_overrides_order_from_other_scope_with_lambdas
+    expected = Developer.order('name DESC').collect { |dev| dev.name }
+    received = Developer.by_salary_with_lambda.reorder_by_name_with_lambda.collect { |dev| dev.name }
+    assert_equal expected, received
+  end
 end
 
 class NestedRelationScopingTest < ActiveRecord::TestCase
diff --git a/activerecord/test/models/developer.rb b/activerecord/test/models/developer.rb
index 32d060c..09fd5ea 100644
--- a/activerecord/test/models/developer.rb
+++ b/activerecord/test/models/developer.rb
@@ -45,6 +45,11 @@ class Developer < ActiveRecord::Base
 
   scope :jamises, :conditions => {:name => 'Jamis'}
 
+  scope :by_salary, order("salary DESC")
+  scope :by_salary_with_lambda, lambda { order("salary DESC") }
+  scope :reorder_by_name, except(:order).order("name DESC")
+  scope :reorder_by_name_with_lambda, lambda { except(:order).order("name DESC") }
+
   validates_inclusion_of :salary, :in => 50000..200000
   validates_length_of    :name, :within => 3..20
 
-- 
1.7.1