fixed defect with select inside of alias joined to the same table (yikes)

4 files changed, 23 insertions, 14 deletions

diff --git a/lib/arel/primitives/attribute.rb b/lib/arel/primitives/attribute.rb
index 5f8618ddfc..22ee37524e 100644
--- a/lib/arel/primitives/attribute.rb
+++ b/lib/arel/primitives/attribute.rb
@@ -47,11 +47,7 @@ module Arel
 
     module Transformations
       def self.included(klass)
-        alias_method :eql?, :==
-      end
-      
-      def hash
-        name.hash + history.size.hash
+        klass.hash_on :name
       end
       
       def as(aliaz = nil)
@@ -70,7 +66,7 @@ module Arel
     
     module Congruence
       def history
-        @history ||= [self] + (ancestor ? [ancestor, ancestor.history].flatten : [])
+        @history ||= [self] + (ancestor ? ancestor.history : [])
       end
       
       def match?(other)
diff --git a/lib/arel/relations/join.rb b/lib/arel/relations/join.rb
index b7c5c3f39b..14903cf01d 100644
--- a/lib/arel/relations/join.rb
+++ b/lib/arel/relations/join.rb
@@ -21,7 +21,7 @@ module Arel
         join_sql,
         externalize(relation2).table_sql(formatter),
         ("ON" unless predicates.blank?),
-        predicates.collect { |p| p.bind(environment).to_sql }.join(' AND ')
+        (predicates + externalize(relation2).selects).collect { |p| p.bind(environment).to_sql }.join(' AND ')
       ].compact.join(" ")
       [relation1.joins(environment), this_join, relation2.joins(environment)].compact.join(" ")
     end
@@ -32,7 +32,7 @@ module Arel
     end
     
     def selects
-      (externalize(relation1).selects + externalize(relation2).selects).collect { |s| s.bind(self) }
+      (externalize(relation1).selects).collect { |s| s.bind(self) }
     end
    
     def table
diff --git a/lib/arel/relations/selection.rb b/lib/arel/relations/selection.rb
index 38a40e1b76..0e7615a83c 100644
--- a/lib/arel/relations/selection.rb
+++ b/lib/arel/relations/selection.rb
@@ -15,7 +15,7 @@ module Arel
     end
     
     def selects
-      relation.selects + [predicate]
+      (relation.selects + [predicate]).collect { |p| p.bind(self) }
     end    
   end
 end
\ No newline at end of file
diff --git a/spec/arel/unit/relations/join_spec.rb b/spec/arel/unit/relations/join_spec.rb
index d517da8c1f..b5c5dc8e33 100644
--- a/spec/arel/unit/relations/join_spec.rb
+++ b/spec/arel/unit/relations/join_spec.rb
@@ -56,14 +56,13 @@ module Arel
           ")
         end
 
-        it 'manufactures sql joining the two tables, merging any selects' do
+        it 'manufactures sql joining the two tables, with selects from the right table in the ON clause' do
           Join.new("INNER JOIN", @relation1.select(@relation1[:id].eq(1)),
                                  @relation2.select(@relation2[:id].eq(2)), @predicate).to_sql.should be_like("
             SELECT `users`.`id`, `users`.`name`, `photos`.`id`, `photos`.`user_id`, `photos`.`camera_id`
             FROM `users`
-              INNER JOIN `photos` ON `users`.`id` = `photos`.`user_id`
+              INNER JOIN `photos` ON `users`.`id` = `photos`.`user_id` AND `photos`.`id` = 2
             WHERE `users`.`id` = 1
-              AND `photos`.`id` = 2
           ")
         end
       end
@@ -158,10 +157,24 @@ module Arel
               SELECT `users`.`id`, `users`.`name`, `users_2`.`id`, `users_2`.`name`
               FROM `users`
                 INNER JOIN `users` AS `users_2`
-                  ON `users`.`id` = `users_2`.`id`
-              WHERE `users_2`.`id` = 1
+                  ON `users`.`id` = `users_2`.`id` AND `users_2`.`id` = 1
             ")
           end
+          
+          describe 'when the selection occurs before the alias' do
+            it 'manufactures sql aliasing the predicates properly' do
+              aliased_relation = @relation1.select(@relation1[:id].eq(1)).alias
+              @relation1                                          \
+                .join(aliased_relation)                           \
+                  .on(aliased_relation[:id].eq(@relation1[:id])) \
+              .to_sql.should be_like("
+                SELECT `users`.`id`, `users`.`name`, `users_2`.`id`, `users_2`.`name`
+                FROM `users`
+                INNER JOIN `users` AS `users_2`
+                  ON `users_2`.`id` = `users`.`id` AND `users_2`.`id` = 1
+              ")
+            end
+          end
         end
         
         describe 'when joining the relation to itself multiple times' do