Pushing a record onto a has_many :through sets the association's foreign key to the associate's primary key and adds it to the correct association. Closes #5829.

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@4792 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

3 files changed, 27 insertions, 13 deletions

diff --git a/activerecord/CHANGELOG b/activerecord/CHANGELOG
index 357f8a4d92..2a9a7c2042 100644
--- a/activerecord/CHANGELOG
+++ b/activerecord/CHANGELOG
@@ -1,6 +1,6 @@
 *SVN*
 
-* Pushing a record onto a has_many :through sets the association's foreign key to the associate's primary key.  #5815 [josh@hasmanythrough.com]
+* Pushing a record onto a has_many :through sets the association's foreign key to the associate's primary key and adds it to the correct association.  #5815, #5829 [josh@hasmanythrough.com]
 
 * PostgreSQL: simplify index introspection query.  #5819 [stephen_purcell@yahoo.com]
 
diff --git a/activerecord/lib/active_record/associations/has_many_through_association.rb b/activerecord/lib/active_record/associations/has_many_through_association.rb
index 0257b1857d..1962dc77ff 100644
--- a/activerecord/lib/active_record/associations/has_many_through_association.rb
+++ b/activerecord/lib/active_record/associations/has_many_through_association.rb
@@ -59,7 +59,8 @@ module ActiveRecord
             raise_on_type_mismatch(associate)
             raise ActiveRecord::HasManyThroughCantAssociateNewRecords.new(@owner, through) unless associate.respond_to?(:new_record?) && !associate.new_record?
 
-            @target << klass.with_scope(:create => construct_join_attributes(associate)) { klass.create! }
+            @owner.send(@reflection.through_reflection.name).proxy_target << klass.with_scope(:create => construct_join_attributes(associate)) { klass.create! }
+            @target << associate
           end
         end
 
diff --git a/activerecord/test/associations_join_model_test.rb b/activerecord/test/associations_join_model_test.rb
index 1a0882fcfb..77908d4540 100644
--- a/activerecord/test/associations_join_model_test.rb
+++ b/activerecord/test/associations_join_model_test.rb
@@ -372,17 +372,30 @@ class AssociationsJoinModelTest < Test::Unit::TestCase
   def test_create_associate_when_adding_to_has_many_through
     count = posts(:thinking).tags.count
     push = Tag.create!(:name => 'pushme')
-    assert_nothing_raised { posts(:thinking).tags << push }
-    assert_equal(count + 1, posts(:thinking).tags.size)
-    assert_equal(count + 1, posts(:thinking).tags(true).size)
-
-    assert_nothing_raised { posts(:thinking).tags.create!(:name => 'foo') }
-    assert_equal(count + 2, posts(:thinking).tags.size)
-    assert_equal(count + 2, posts(:thinking).tags(true).size)
-
-    assert_nothing_raised { posts(:thinking).tags.concat(Tag.create!(:name => 'abc'), Tag.create!(:name => 'def')) }
-    assert_equal(count + 4, posts(:thinking).tags.size)
-    assert_equal(count + 4, posts(:thinking).tags(true).size)
+    post_thinking = posts(:thinking)
+    assert_nothing_raised { post_thinking.tags << push }
+    assert_nil( wrong = post_thinking.tags.detect { |t| t.class != Tag },
+                message = "Expected a Tag in tags collection, got #{wrong.class}.")
+    assert_nil( wrong = post_thinking.taggings.detect { |t| t.class != Tagging },
+                message = "Expected a Tagging in taggings collection, got #{wrong.class}.")
+    assert_equal(count + 1, post_thinking.tags.size)
+    assert_equal(count + 1, post_thinking.tags(true).size)
+
+    assert_nothing_raised { post_thinking.tags.create!(:name => 'foo') }
+    assert_nil( wrong = post_thinking.tags.detect { |t| t.class != Tag },
+                message = "Expected a Tag in tags collection, got #{wrong.class}.")
+    assert_nil( wrong = post_thinking.taggings.detect { |t| t.class != Tagging },
+                message = "Expected a Tagging in taggings collection, got #{wrong.class}.")
+    assert_equal(count + 2, post_thinking.tags.size)
+    assert_equal(count + 2, post_thinking.tags(true).size)
+
+    assert_nothing_raised { post_thinking.tags.concat(Tag.create!(:name => 'abc'), Tag.create!(:name => 'def')) }
+    assert_nil( wrong = post_thinking.tags.detect { |t| t.class != Tag },
+                message = "Expected a Tag in tags collection, got #{wrong.class}.")
+    assert_nil( wrong = post_thinking.taggings.detect { |t| t.class != Tagging },
+                message = "Expected a Tagging in taggings collection, got #{wrong.class}.")
+    assert_equal(count + 4, post_thinking.tags.size)
+    assert_equal(count + 4, post_thinking.tags(true).size)
   end
 
   def test_adding_junk_to_has_many_through_should_raise_type_mismatch