Do not authorize project identifier with numbers only (would be interpreted as the project id in urls).

git-svn-id: http://redmine.rubyforge.org/svn/trunk@1108 e93f8b46-1217-0410-a6f0-8f06a7374b81

app/models/project.rb

@@ -217,6 +217,7 @@ protected
   def validate
     errors.add(parent_id, " must be a root project") if parent and parent.parent
     errors.add_to_base("A project with subprojects can't be a subproject") if parent and children.size > 0
+    errors.add(:identifier, :activerecord_error_invalid) if !identifier.blank? && identifier.match(/^\d*$/)
   end
   
 private