Alias included associations if needed when doing a count

[#302 state:resolved]

Signed-off-by: Jeremy Kemper <jeremy@bitsweat.net>

activerecord/lib/active_record/calculations.rb

@@ -186,11 +186,17 @@ def construct_calculation_sql(operation, column_name, options) #:nodoc:
             sql << " FROM (SELECT #{distinct}#{column_name}" if use_workaround
             sql << " FROM #{connection.quote_table_name(table_name)} "
           end
+
+          joins = ""
+          add_joins!(joins, options, scope)
+
           if merged_includes.any?
-            join_dependency = ActiveRecord::Associations::ClassMethods::JoinDependency.new(self, merged_includes, options[:joins])
+            join_dependency = ActiveRecord::Associations::ClassMethods::JoinDependency.new(self, merged_includes, joins)
             sql << join_dependency.join_associations.collect{|join| join.association_join }.join
           end
-          add_joins!(sql, options, scope)
+
+          sql << joins unless joins.blank?
+
           add_conditions!(sql, options[:conditions], scope)
           add_limited_ids_condition!(sql, options, join_dependency) if join_dependency && !using_limitable_reflections?(join_dependency.reflections) && ((scope && scope[:limit]) || options[:limit])
 

activerecord/test/cases/associations/has_many_through_associations_test.rb

@@ -193,4 +193,8 @@ def test_dynamic_find_should_respect_association_include
     # due to Unknown column 'comments.id'
     assert Person.find(1).posts_with_comments_sorted_by_comment_id.find_by_title('Welcome to the weblog')
   end
+
+  def test_count_with_include_should_alias_join_table
+    assert_equal 2, people(:michael).posts.count(:include => :readers)
+  end
 end