Merge branch 'order-stages-by-pipeline' into 'master'

Render stages in valid order

Currently stages in stages dropdown on builds page are not in valid order. It is important to display stages in other those are defined in the pipeline.

Fixes https://gitlab.com/gitlab-org/gitlab-ce/issues/21133

See merge request !6430

CHANGELOG

@@ -18,6 +18,7 @@ v 8.12.0 (unreleased)
   - API: Ensure invitees are not returned in Members API.
   - Add two-factor recovery endpoint to internal API !5510
   - Pass the "Remember me" value to the U2F authentication form
+  - Display stages in valid order in stages dropdown on build page
   - Only update projects.last_activity_at once per hour when creating a new event
   - Remove vendor prefixes for linear-gradient CSS (ClemMakesApps)
   - Move pushes_since_gc from the database to Redis

app/views/projects/builds/_sidebar.html.haml

@@ -112,14 +112,14 @@
           %span.label.label-primary
             = tag
 
-    - if builds.size > 1
+    - if @build.pipeline.stages.many?
       .dropdown.build-dropdown
         .title Stage
         %button.dropdown-menu-toggle{type: 'button', 'data-toggle' => 'dropdown'}
           %span.stage-selection More
           = icon('caret-down')
         %ul.dropdown-menu
-          - builds.map(&:stage).uniq.each do |stage|
+          - @build.pipeline.stages.each do |stage|
             %li
               %a.stage-item= stage