Adds permissions for viewing the watcher list and adding new watchers on the issue detail view (#398).

git-svn-id: http://redmine.rubyforge.org/svn/trunk@1712 e93f8b46-1217-0410-a6f0-8f06a7374b81

app/models/watcher.rb

@@ -19,5 +19,12 @@ class Watcher < ActiveRecord::Base
   belongs_to :watchable, :polymorphic => true
   belongs_to :user
   
+  validates_presence_of :user
   validates_uniqueness_of :user_id, :scope => [:watchable_type, :watchable_id]
+  
+  protected
+  
+  def validate
+    errors.add :user_id, :activerecord_error_invalid unless user.nil? || user.active?
+  end
 end