In stead of destroying messages when their notifiables

are destroyed (which could lead to messages becoming 
invisible), we nullify the notifiable references.

Since AR's dependent => nullify only nullifies the
id, not the type, a before_destroy filter is introduced.

1 files changed, 8 insertions, 1 deletions

diff --git a/app/models/merge_request.rb b/app/models/merge_request.rb
index 4462215..f524e16 100644
--- a/app/models/merge_request.rb
+++ b/app/models/merge_request.rb
@@ -25,9 +25,11 @@ class MergeRequest < ActiveRecord::Base
   belongs_to :source_repository, :class_name => 'Repository'
   belongs_to :target_repository, :class_name => 'Repository'
   has_many   :events, :as => :target, :dependent => :destroy
-  has_many :messages, :as => :notifiable, :dependent => :destroy
+  has_many :messages, :as => :notifiable
   has_many :comments, :as => :target, :dependent => :destroy
   
+  before_destroy :nullify_messages
+  
   is_indexed :fields => ["proposal"], :include => [{
       :association_name => "user",
       :field => "login",
@@ -360,4 +362,9 @@ class MergeRequest < ActiveRecord::Base
     response = access_token.get("/")
     return Net::HTTPSuccess === response
   end
+  
+  def nullify_messages
+    messages.update_all({:notifiable_id => nil, :notifiable_type => nil})
+  end
+  
 end