A category with assigned issue can now be deleted. 2 options are proposed:

* remove assignments (issues are set to 'no category')
* reassign issues to another category (if at least an other category exists)
If no issue is assigned to the category, it's deleted silently.

git-svn-id: http://redmine.rubyforge.org/svn/trunk@733 e93f8b46-1217-0410-a6f0-8f06a7374b81

app/models/issue_category.rb

@@ -16,15 +16,21 @@
 # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 
 class IssueCategory < ActiveRecord::Base
-  before_destroy :check_integrity  
   belongs_to :project
   belongs_to :assigned_to, :class_name => 'User', :foreign_key => 'assigned_to_id'
-
+  has_many :issues, :foreign_key => 'category_id', :dependent => :nullify
+  
   validates_presence_of :name
   validates_uniqueness_of :name, :scope => [:project_id]
   
-private
-  def check_integrity
-    raise "Can't delete category" if Issue.find(:first, :conditions => ["category_id=?", self.id])
+  alias :destroy_without_reassign :destroy
+  
+  # Destroy the category
+  # If a category is specified, issues are reassigned to this category
+  def destroy(reassign_to = nil)
+    if reassign_to && reassign_to.is_a?(IssueCategory) && reassign_to.project == self.project
+      Issue.update_all("category_id = #{reassign_to.id}", "category_id = #{id}")
+    end
+    destroy_without_reassign
   end
 end