Don't clobber :includes passed to count on has_many association. Closes #9175 [danger]

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@7326 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

activerecord/CHANGELOG

@@ -1,5 +1,7 @@
 *SVN*
 
+* Don't clobber includes passed to has_many.count [danger]
+
 * Make sure has_many uses :include when counting [danger]
 
 * Change the implementation of ActiveRecord's attribute reader and writer methods [nzkoz]

activerecord/lib/active_record/associations/has_many_association.rb

@@ -31,7 +31,7 @@ module ActiveRecord
           options[:conditions] = options[:conditions].nil? ?
             @finder_sql :
             @finder_sql + " AND (#{sanitize_sql(options[:conditions])})"
-          options[:include] = @reflection.options[:include]
+          options[:include] ||= @reflection.options[:include]
 
           @reflection.klass.count(column_name, options)
         end

activerecord/test/associations/eager_test.rb

@@ -168,6 +168,12 @@ class EagerAssociationTest < Test::Unit::TestCase
     posts = Post.find(:all, :include => [ :author, :comments ], :limit => 2, :conditions => "posts.title = 'magic forest'")
     assert_equal 0, posts.size
   end
+  
+  def test_eager_count_performed_on_a_has_many_association_with_multi_table_conditional
+    author = authors(:david)
+    author_posts_without_comments = author.posts.select { |post| post.comments.blank? }
+    assert_equal author_posts_without_comments.size, author.posts.count(:all, :include => :comments, :conditions => 'comments.id is null')
+  end
 
   def test_eager_with_has_and_belongs_to_many_and_limit
     posts = Post.find(:all, :include => :categories, :order => "posts.id", :limit => 3)