フォーム再表示時にグループに属するユーザーにチェックが入らないようにする

app/helpers/watchers_helper.rb

@@ -74,7 +74,7 @@ def watchers_list(object)
 
   def watchers_checkboxes(object, users, checked=nil)
     users.map do |user|
-      c = checked.nil? ? object.watched_by?(user) : checked
+      c = checked.nil? ? object.watcher_user_ids.include?(user.id) : checked
       tag = check_box_tag 'issue[watcher_user_ids][]', user.id, c, :id => nil
       content_tag 'label', "#{tag} #{h(user)}".html_safe,
                   :id => "issue_watcher_user_ids_#{user.id}",

test/functional/issues_controller_test.rb

@@ -4778,6 +4778,24 @@ def test_post_create_with_failure_should_preserve_watchers
     assert_select 'input[name=?][value="8"][checked=checked]', 'issue[watcher_user_ids][]'
   end
 
+  def test_post_create_with_failure_should_not_dereference_group_watchers
+    @request.session[:user_id] = 1
+    post(
+      :create,
+      :params => {
+        :project_id => 5,
+        :issue => {
+          :tracker_id => 1,
+          :watcher_user_ids => ['11']
+        }
+      }
+    )
+    assert_response :success
+
+    assert_select 'input[name=?][value="8"][checked=checked]', 'issue[watcher_user_ids][]', 0
+    assert_select 'input[name=?][value="11"][checked=checked]', 'issue[watcher_user_ids][]', 1
+  end
+
   def test_post_create_should_ignore_non_safe_attributes
     @request.session[:user_id] = 2
     assert_nothing_raised do