Save 1 query + 1 cache hit in #shared_versions for root projects.

git-svn-id: svn+ssh://rubyforge.org/var/svn/redmine/trunk@5243 e93f8b46-1217-0410-a6f0-8f06a7374b81

app/models/project.rb

@@ -379,15 +379,17 @@ class Project < ActiveRecord::Base
   
   # Returns a scope of the Versions used by the project
   def shared_versions
-    @shared_versions ||= 
+    @shared_versions ||= begin
+      r = root? ? self : root
       Version.scoped(:include => :project,
                      :conditions => "#{Project.table_name}.id = #{id}" +
                                     " OR (#{Project.table_name}.status = #{Project::STATUS_ACTIVE} AND (" +
                                           " #{Version.table_name}.sharing = 'system'" +
-                                          " OR (#{Project.table_name}.lft >= #{root.lft} AND #{Project.table_name}.rgt <= #{root.rgt} AND #{Version.table_name}.sharing = 'tree')" +
+                                          " OR (#{Project.table_name}.lft >= #{r.lft} AND #{Project.table_name}.rgt <= #{r.rgt} AND #{Version.table_name}.sharing = 'tree')" +
                                           " OR (#{Project.table_name}.lft < #{lft} AND #{Project.table_name}.rgt > #{rgt} AND #{Version.table_name}.sharing IN ('hierarchy', 'descendants'))" +
                                           " OR (#{Project.table_name}.lft > #{lft} AND #{Project.table_name}.rgt < #{rgt} AND #{Version.table_name}.sharing = 'hierarchy')" +
                                           "))")
+    end
   end
 
   # Returns a hash of project users grouped by role