SELECT DISTINCT instead of using group hack, and fix a glitch with grafting

lib/ransack/adapters/active_record/context.rb

@@ -12,7 +12,7 @@ module Ransack
         def evaluate(search, opts = {})
           viz = Visitor.new
           relation = @object.where(viz.accept(search.base)).order(viz.accept(search.sorts))
-          opts[:distinct] ? relation.group(@klass.arel_table[@klass.primary_key]) : relation
+          opts[:distinct] ? relation.select("DISTINCT #{@klass.quoted_table_name}.*") : relation
         end
 
         def attribute_method?(str, klass = @klass)
@@ -98,7 +98,7 @@ module Ransack
         end
 
         def join_dependency(relation)
-          if relation.respond_to?(:join_dependency) # MetaWhere will enable this
+          if relation.respond_to?(:join_dependency) # Squeel will enable this
             relation.join_dependency
           else
             build_join_dependency(relation)
@@ -112,7 +112,7 @@ module Ransack
               'string_join'
             when Hash, Symbol, Array
               'association_join'
-            when ActiveRecord::Associations::JoinDependency::JoinAssociation
+            when ::ActiveRecord::Associations::JoinDependency::JoinAssociation
               'stashed_join'
             when Arel::Nodes::Join
               'join_node'

lib/ransack/adapters/active_record/join_association.rb

@@ -26,7 +26,7 @@ module Ransack
         end
 
         def ==(other)
-          super && reflection.klass == other.reflection.klass
+          super && active_record == other.active_record
         end
 
         # This is a temporary hack. Jon's going to refactor this in AR to

lib/ransack/adapters/active_record/join_dependency.rb

@@ -18,11 +18,7 @@ module Ransack
         def graft_with_ransack(*associations)
           associations.each do |association|
             join_associations.detect {|a| association == a} ||
-            (
-              association.options[:polymorphic] ?
-              build_polymorphic(association.reflection.name, association.find_parent_in(self) || join_base, association.join_type, association.reflection.klass) :
-              build(association.reflection.name, association.find_parent_in(self) || join_base, association.join_type)
-            )
+              build_polymorphic(association.reflection.name, association.find_parent_in(self) || join_base, association.join_type, association.reflection.klass)
           end
           self
         end

lib/ransack/search.rb

@@ -22,7 +22,7 @@ module Ransack
     end
 
     def result(opts = {})
-      @result ||= @context.evaluate(self, opts)
+      @context.evaluate(self, opts)
     end
 
     def build(params)

spec/ransack/search_spec.rb

@@ -123,6 +123,13 @@ module Ransack
         where = search.result.where_values.first
         where.to_sql.should match /\(\("people"."name" = 'Ernie' OR "children_people"."name" = 'Ernie'\) AND \("people"."name" = 'Bert' OR "children_people"."name" = 'Bert'\)\)/
       end
+
+      it 'returns distinct records when passed :distinct => true' do
+        search = Search.new(Person, :o => [{:comments_body_cont => 'e', :articles_comments_body_cont => 'e'}])
+        search.result.should have(920).items
+        search.result(:distinct => true).should have(330).items
+        search.result.all.uniq.should eq search.result(:distinct => true).all
+      end
     end
 
     describe '#sorts=' do