From 01b3c88f5137d8ce98daafc62a88cb953a61bcc6 Mon Sep 17 00:00:00 2001
From: Tatsuya Ono <ononoma@gmail.com>
Date: Mon, 11 Jan 2010 21:18:49 +0000
Subject: [PATCH 1/2] added a test to reproduce issue on joining with has_one-through association.

---
 activerecord/test/cases/finder_test.rb |   17 +++++++++++++++++
 activerecord/test/models/comment.rb    |    1 +
 2 files changed, 18 insertions(+), 0 deletions(-)

diff --git a/activerecord/test/cases/finder_test.rb b/activerecord/test/cases/finder_test.rb
index f1bede9..b5eb75d 100644
--- a/activerecord/test/cases/finder_test.rb
+++ b/activerecord/test/cases/finder_test.rb
@@ -1043,6 +1043,23 @@ class FinderTest < ActiveRecord::TestCase
     end
   end
 
+  def test_finder_with_association
+    comments_on_thinking = Post.find(2).comments.count
+    
+    comments = Comment.find :all, :conditions=>["posts.title = ?", "So I was thinking"], :joins=>[:post]
+    
+    assert_equal comments_on_thinking, comments.size    
+  end
+  
+  def test_finder_with_association_through
+    david = Author.find 1
+    comments_on_david = david.posts.inject(0) {|sum, post| sum += post.comments.count }
+    
+    comments = Comment.find :all, :conditions=>["authors.name = ?", "David"], :joins=>[:post_author]
+    
+    assert_equal comments_on_david, comments.size    
+  end
+
   protected
     def bind(statement, *vars)
       if vars.first.is_a?(Hash)
diff --git a/activerecord/test/models/comment.rb b/activerecord/test/models/comment.rb
index 399dea9..b39d1ea 100644
--- a/activerecord/test/models/comment.rb
+++ b/activerecord/test/models/comment.rb
@@ -6,6 +6,7 @@ class Comment < ActiveRecord::Base
               :conditions => { "posts.author_id" => 1 }
 
   belongs_to :post, :counter_cache => true
+  has_one :post_author, :through=>:post, :source=>:author
 
   def self.what_are_you
     'a comment...'
-- 
1.6.6


From c52b06fda580b4d4c85eab7d1144e5a17cc7e74c Mon Sep 17 00:00:00 2001
From: Tatsuya Ono <ononoma@gmail.com>
Date: Mon, 11 Jan 2010 23:14:21 +0000
Subject: [PATCH 2/2] fixed an issue on joining with has_one-through association.

---
 activerecord/lib/active_record/associations.rb |   30 ++++++++++++++---------
 1 files changed, 18 insertions(+), 12 deletions(-)

diff --git a/activerecord/lib/active_record/associations.rb b/activerecord/lib/active_record/associations.rb
index 3ff8aba..70a67aa 100755
--- a/activerecord/lib/active_record/associations.rb
+++ b/activerecord/lib/active_record/associations.rb
@@ -2082,18 +2082,24 @@ module ActiveRecord
                     when reflection.options[:through]
                       through_conditions = through_reflection.options[:conditions] ? "AND #{interpolate_sql(sanitize_sql(through_reflection.options[:conditions]))}" : ''
 
-                      jt_foreign_key = jt_as_extra = jt_source_extra = jt_sti_extra = nil
+                      jt_first_key = jt_second_key = jt_as_extra = jt_source_extra = jt_sti_extra = nil
                       first_key = second_key = as_extra = nil
-
-                      if through_reflection.options[:as] # has_many :through against a polymorphic join
-                        jt_foreign_key = through_reflection.options[:as].to_s + '_id'
-                        jt_as_extra = " AND %s.%s = %s" % [
-                          connection.quote_table_name(aliased_join_table_name),
-                          connection.quote_column_name(through_reflection.options[:as].to_s + '_type'),
-                          klass.quote_value(parent.active_record.base_class.name)
-                        ]
+                      
+                      if through_reflection.macro == :belongs_to
+                        jt_first_key = through_reflection.primary_key_name
+                        jt_second_key = parent.primary_key
                       else
-                        jt_foreign_key = through_reflection.primary_key_name
+                        jt_first_key = parent.primary_key
+                        if through_reflection.options[:as] # has_many :through against a polymorphic join
+                          jt_second_key = through_reflection.options[:as].to_s + '_id'
+                          jt_as_extra = " AND %s.%s = %s" % [
+                            connection.quote_table_name(aliased_join_table_name),
+                            connection.quote_column_name(through_reflection.options[:as].to_s + '_type'),
+                            klass.quote_value(parent.active_record.base_class.name)
+                          ]
+                        else
+                          jt_second_key = through_reflection.primary_key_name
+                        end
                       end
 
                       case source_reflection.macro
@@ -2134,9 +2140,9 @@ module ActiveRecord
                       " #{join_type} %s ON (%s.%s = %s.%s%s%s%s) " % [
                         table_alias_for(through_reflection.klass.table_name, aliased_join_table_name),
                         connection.quote_table_name(parent.aliased_table_name),
-                        connection.quote_column_name(parent.primary_key),
+                        connection.quote_column_name(jt_first_key),
                         connection.quote_table_name(aliased_join_table_name),
-                        connection.quote_column_name(jt_foreign_key),
+                        connection.quote_column_name(jt_second_key),
                         jt_as_extra, jt_source_extra, jt_sti_extra
                       ] +
                       " #{join_type} %s ON (%s.%s = %s.%s%s) " % [
-- 
1.6.6