From b015a0f688ba99f290e78fcf04eaa4c2c43e6eed Mon Sep 17 00:00:00 2001
From: Durran Jordan <durran@gmail.com>
Date: Tue, 9 Mar 2010 15:43:12 -0500
Subject: [PATCH] Allow setting of parent in belongs to related to nil

---
 lib/mongoid/associations/belongs_to_related.rb    | 15 ++++++---------
 .../associations/belongs_to_related_spec.rb       |  4 ++++
 2 files changed, 10 insertions(+), 9 deletions(-)

diff --git a/lib/mongoid/associations/belongs_to_related.rb b/lib/mongoid/associations/belongs_to_related.rb
index 4aae9441eb..0944227042 100644
--- a/lib/mongoid/associations/belongs_to_related.rb
+++ b/lib/mongoid/associations/belongs_to_related.rb
@@ -41,19 +41,16 @@ def macro
         #
         # Options:
         #
-        # related: The related object
-        # parent: The parent +Document+ to update.
+        # target: The target(parent) object
+        # document: The +Document+ to update.
         # options: The association +Options+
         #
         # Example:
         #
-        # <tt>BelongsToRelated.update(game, person, options)</tt>
-        def update(target, parent, options)
-          if target
-            parent.send("#{options.foreign_key}=", target.id)
-            return instantiate(parent, options, target)
-          end
-          target
+        # <tt>BelongsToRelated.update(person, game, options)</tt>
+        def update(target, document, options)
+          document.send("#{options.foreign_key}=", target ? target.id : nil)
+          instantiate(document, options, target)
         end
       end
 
diff --git a/spec/unit/mongoid/associations/belongs_to_related_spec.rb b/spec/unit/mongoid/associations/belongs_to_related_spec.rb
index 1669fc6b8c..f33382326f 100644
--- a/spec/unit/mongoid/associations/belongs_to_related_spec.rb
+++ b/spec/unit/mongoid/associations/belongs_to_related_spec.rb
@@ -134,6 +134,10 @@ def extension
         Mongoid::Associations::BelongsToRelated.update(nil, @child, @options).should be_nil
       end
 
+      it "removes the association" do
+        Mongoid::Associations::BelongsToRelated.update(nil, @child, @options)
+        @child.person.should be_nil
+      end
     end
 
   end