Merged r19586 from trunk to 4.1-stable (#33176).

git-svn-id: http://svn.redmine.org/redmine/branches/4.1-stable@19587 e93f8b46-1217-0410-a6f0-8f06a7374b81

app/helpers/sort_helper.rb

@@ -115,10 +115,10 @@ module SortHelper
 
     if column.to_s == @sort_criteria.first_key
       if @sort_criteria.first_asc?
-        css = 'sort asc'
+        css = 'sort asc icon icon-sorted-desc'
         order = 'desc'
       else
-        css = 'sort desc'
+        css = 'sort desc icon icon-sorted-asc'
         order = 'asc'
       end
     end