Merge branch 'fix-regression-in-handling-build-updated' into 'master'

Fix processing of events when build finished.

Update pipeline after processing builds. Otherwise we can get into scenario where pipeline will be marked as running.

This solves a quite significant regression in Pipeline processing.

Proper fix is to move all this to Sidekiq Worker and process pipeline there.
I'll do it after 8.12 release.

See merge request !6410

app/models/ci/pipeline.rb

@@ -242,6 +242,8 @@ module Ci
     end
 
     def build_updated
+      with_lock do
+        reload
         case latest_builds_status
         when 'pending' then enqueue
         when 'running' then run
@@ -251,6 +253,7 @@ module Ci
         when 'skipped' then skip
         end
       end
+    end
 
     def predefined_variables
       [

app/models/commit_status.rb

@@ -69,15 +69,15 @@ class CommitStatus < ActiveRecord::Base
       commit_status.update_attributes finished_at: Time.now
     end
 
-    after_transition do |commit_status, transition|
-      commit_status.pipeline.try(:build_updated) unless transition.loopback?
-    end
-
     after_transition any => [:success, :failed, :canceled] do |commit_status|
       commit_status.pipeline.try(:process!)
       true
     end
 
+    after_transition do |commit_status, transition|
+      commit_status.pipeline.try(:build_updated) unless transition.loopback?
+    end
+
     after_transition [:created, :pending, :running] => :success do |commit_status|
       MergeRequests::MergeWhenBuildSucceedsService.new(commit_status.pipeline.project, nil).trigger(commit_status)
     end