Add test_has_many_through_has_and_belongs_to_many_with_has_many_source_reflection and make it work

3 files changed, 41 insertions, 4 deletions

diff --git a/activerecord/lib/active_record/associations/through_association_scope.rb b/activerecord/lib/active_record/associations/through_association_scope.rb
index 25fde49650..582474355e 100644
--- a/activerecord/lib/active_record/associations/through_association_scope.rb
+++ b/activerecord/lib/active_record/associations/through_association_scope.rb
@@ -23,8 +23,15 @@ module ActiveRecord
       # TODO: Conditions on joins
       def construct_conditions
         reflection = @reflection.through_reflection_chain.last
+        
+        if reflection.macro == :has_and_belongs_to_many
+          table_alias = table_aliases[reflection].first
+        else
+          table_alias = table_aliases[reflection]
+        end
+        
         conditions = construct_quoted_owner_attributes(reflection).map do |attr, value|
-          "#{table_aliases[reflection]}.#{attr} = #{value}"
+          "#{table_alias}.#{attr} = #{value}"
         end
         conditions << sql_conditions if sql_conditions
         "(" + conditions.join(') AND (') + ")"
@@ -97,12 +104,30 @@ module ActiveRecord
                   source_type_conditions(left)
                 )
               when :has_many, :has_one
+                if right.macro == :has_and_belongs_to_many
+                  join_table, right_table = table_aliases[right]
+                  right_table_and_alias = table_name_and_alias(right.quoted_table_name, right_table)
+                else
+                  right_table = table_aliases[right]
+                end
+              
                 joins << inner_join_sql(
                   right_table_and_alias,
-                  table_aliases[left],  left.source_reflection.primary_key_name,
-                  table_aliases[right], right.klass.primary_key,
+                  table_aliases[left], left.source_reflection.primary_key_name,
+                  right_table,         right.klass.primary_key,
                   polymorphic_conditions(left, left.source_reflection.options[:as])
                 )
+                
+                if right.macro == :has_and_belongs_to_many
+                  joins << inner_join_sql(
+                    table_name_and_alias(
+                      quote_table_name(right.options[:join_table]),
+                      join_table
+                    ),
+                    right_table, right.klass.primary_key,
+                    join_table,  right.association_foreign_key
+                  )
+                end
               when :has_and_belongs_to_many
                 join_table, left_table = table_aliases[left]
                 
diff --git a/activerecord/test/cases/associations/nested_has_many_through_associations_test.rb b/activerecord/test/cases/associations/nested_has_many_through_associations_test.rb
index 964112b006..4e7e766b14 100644
--- a/activerecord/test/cases/associations/nested_has_many_through_associations_test.rb
+++ b/activerecord/test/cases/associations/nested_has_many_through_associations_test.rb
@@ -169,9 +169,19 @@ class NestedHasManyThroughAssociationsTest < ActiveRecord::TestCase
     assert_equal [categories(:general), categories(:cooking)], authors[2].post_categories
   end
   
-  # TODO: has_many through
+  # has_many through
   # Source: has_many
   # Through: has_and_belongs_to_many
+  def test_has_many_through_has_and_belongs_to_many_with_has_many_source_reflection
+    assert_equal [comments(:greetings), comments(:more_greetings)], categories(:technology).post_comments
+    
+    categories = Category.joins(:post_comments).where('comments.id' => comments(:more_greetings).id)
+    assert_equal [categories(:general), categories(:technology)], categories
+    
+    # TODO: Make this work
+    # categories = Category.includes(:post_comments)
+    # assert_equal [comments(:greetings), comments(:more_greetings)], categories[1].post_comments
+  end
   
   # TODO: has_many through
   # Source: belongs_to
diff --git a/activerecord/test/models/category.rb b/activerecord/test/models/category.rb
index 48415846dd..c933943813 100644
--- a/activerecord/test/models/category.rb
+++ b/activerecord/test/models/category.rb
@@ -23,6 +23,8 @@ class Category < ActiveRecord::Base
 
   has_many :categorizations
   has_many :authors, :through => :categorizations, :select => 'authors.*, categorizations.post_id'
+  
+  has_many :post_comments, :through => :posts, :source => :comments
 end
 
 class SpecialCategory < Category