Count users with a single query on group list (#16905).

git-svn-id: http://svn.redmine.org/redmine/trunk@13149 e93f8b46-1217-0410-a6f0-8f06a7374b81

app/controllers/groups_controller.rb

@@ -26,9 +26,10 @@ class GroupsController < ApplicationController
 
   def index
     @groups = Group.sorted.all
-
     respond_to do |format|
-      format.html
+      format.html {
+        @user_count_by_group_id = user_count_by_group_id
+      }
       format.api
     end
   end
@@ -138,4 +139,12 @@ class GroupsController < ApplicationController
   rescue ActiveRecord::RecordNotFound
     render_404
   end
+
+  def user_count_by_group_id
+    h = User.joins(:groups).group('group_id').count
+    h.keys.each do |key|
+      h[key.to_i] = h.delete(key)
+    end
+    h
+  end
 end