Fix errors caused by assigning a has-one or belongs-to property to itself

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@2562 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

4 files changed, 15 insertions, 3 deletions

diff --git a/activerecord/CHANGELOG b/activerecord/CHANGELOG
index 8aa05e88ce..5024362bf5 100644
--- a/activerecord/CHANGELOG
+++ b/activerecord/CHANGELOG
@@ -1,5 +1,7 @@
 *SVN*
 
+* Fix errors caused by assigning a has-one or belongs-to property to itself
+
 * Add ActiveRecord::Base.schema_format setting which specifies how databases should be dumped [Sam Stephenson]
 
 * Optimize postgresql selects. [skaes@web.de]
diff --git a/activerecord/lib/active_record/associations/belongs_to_association.rb b/activerecord/lib/active_record/associations/belongs_to_association.rb
index 681bd1b88d..9dc0e26e10 100644
--- a/activerecord/lib/active_record/associations/belongs_to_association.rb
+++ b/activerecord/lib/active_record/associations/belongs_to_association.rb
@@ -30,7 +30,7 @@ module ActiveRecord
         else
           raise_on_type_mismatch(obj) unless obj.nil?
 
-          @target = obj
+          @target = (AssociationProxy === obj ? obj.target : obj)
           @owner[@association_class_primary_key_name] = obj.id unless obj.new_record?
           @updated = true
         end
diff --git a/activerecord/lib/active_record/associations/has_one_association.rb b/activerecord/lib/active_record/associations/has_one_association.rb
index 1550db69b5..1ff67ff70a 100644
--- a/activerecord/lib/active_record/associations/has_one_association.rb
+++ b/activerecord/lib/active_record/associations/has_one_association.rb
@@ -29,7 +29,7 @@ module ActiveRecord
       def replace(obj, dont_save = false)
         load_target
         unless @target.nil?
-          if dependent? && !dont_save     
+          if dependent? && !dont_save && @target != obj
             @target.destroy unless @target.new_record?
             @owner.clear_association_cache
           else
@@ -44,7 +44,7 @@ module ActiveRecord
           raise_on_type_mismatch(obj)
           
           obj[@association_class_primary_key_name] = @owner.id unless @owner.new_record?
-          @target = obj
+          @target = (AssociationProxy === obj ? obj.target : obj)
         end
 
         @loaded = true
diff --git a/activerecord/test/associations_test.rb b/activerecord/test/associations_test.rb
index af4251284d..fc8d59e862 100755
--- a/activerecord/test/associations_test.rb
+++ b/activerecord/test/associations_test.rb
@@ -72,6 +72,11 @@ class HasOneAssociationsTest < Test::Unit::TestCase
     assert_equal Account.find(1).credit_limit, companies(:first_firm).account.credit_limit
   end
 
+  def test_proxy_assignment
+    company = companies(:first_firm)
+    assert_nothing_raised { company.account = company.account }
+  end
+
   def test_triple_equality
     assert Account === companies(:first_firm).account
   end
@@ -692,6 +697,11 @@ class BelongsToAssociationsTest < Test::Unit::TestCase
     assert !Client.find(3).firm.nil?, "Microsoft should have a firm"   
   end
 
+  def test_proxy_assignment
+    account = Account.find(1)
+    assert_nothing_raised { account.firm = account.firm }
+  end
+
   def test_type_mismatch
     assert_raise(ActiveRecord::AssociationTypeMismatch) { Account.find(1).firm = 1 }
     assert_raise(ActiveRecord::AssociationTypeMismatch) { Account.find(1).firm = Project.find(1) }