#759: refactoring according to Vladimir's comments

app/controllers/projects/build_lists_controller.rb

@@ -100,15 +100,12 @@ class Projects::BuildListsController < Projects::BaseController
   end
 
   def cancel
-    if @build_list.new_core? && @build_list.can_cancel?
-      @build_list.cancel_job
-      notice = t('layout.build_lists.will_be_canceled')
+    if @build_list.cancel
+      notice = @build_list.new_core? ?
+       t('layout.build_lists.will_be_canceled') :
+       t('layout.build_lists.cancel_success')
     else
-      if @build_list.cancel
-        notice = t('layout.build_lists.cancel_success')
-      else
-        notice = t('layout.build_lists.cancel_fail')
-      end
+      notice = t('layout.build_lists.cancel_fail')
     end
     redirect_to :back, :notice => notice
   end

app/models/build_list.rb

@@ -141,6 +141,8 @@ class BuildList < ActiveRecord::Base
     end
 
     after_transition :on => :published, :do => [:set_version_and_tag, :actualize_packages]
+    after_transition :on => :cancel, :do => [:cancel_job],
+      :if => lambda { |build_list| build_list.build_canceling? }
 
     after_transition :on => [:published, :fail_publish, :build_error], :do => :notify_users
     after_transition :on => :build_success, :do => :notify_users,
@@ -175,6 +177,15 @@ class BuildList < ActiveRecord::Base
       transition [:build_pending, :platform_pending] => :build_canceled, :if => lambda { |build_list|
         !build_list.new_core? && build_list.can_cancel? && BuildServer.delete_build_list(build_list.bs_id) == BuildServer::SUCCESS
       }
+      transition [:build_pending, :build_started] => :build_canceling, :if => lambda { |build_list|
+        build_list.new_core? && build_list.can_cancel?
+      }
+    end
+
+    event :build_canceled do
+      transition [:build_canceling] => :build_canceled, :if => lambda { |build_list|
+        build_list.new_core?
+      }
     end
 
     event :published do

lib/abf_worker/rpm_worker_observer.rb

@@ -24,7 +24,7 @@ module AbfWorker
         bl.save!
         bl.start_build
       when BUILD_CANCELED
-        bl.update_attributes({:status => BuildList::BUILD_CANCELED})
+        bl.build_canceled
         item.update_attributes({:status => BuildList::BUILD_CANCELED})
       end
       if status != BUILD_STARTED