Merge branch 'issue_14610' into 'master'

Fix cancel button on issuable edit form

See merge request !3392

CHANGELOG

@@ -14,6 +14,7 @@ v 8.6.2
   - Fix an issue hiding the password form when signed-in with a linked account. !3381
   - Add links to CI setup documentation from project settings and builds pages. !3384
   - Fix an issue with width of project select dropdown. !3386
+  - Fix error 500 with cancel button on issuable edit form. !3392
 
 v 8.6.2 (unreleased)
   - Comments on confidential issues don't show up in activity feed to non-members

app/views/shared/issuable/_form.html.haml

@@ -127,7 +127,7 @@
       for this project.
 
   - if issuable.new_record?
-    = link_to 'Cancel', namespace_project_issues_path(@project.namespace, @project), class: 'btn btn-cancel'
+    = link_to 'Cancel', polymorphic_path([@project.namespace, @project, issuable.class]), class: 'btn btn-cancel'
   - else
     .pull-right
       - if current_user.can?(:"destroy_#{issuable.to_ability_name}", @project)
@@ -135,4 +135,4 @@
                                                                                                   method: :delete, class: 'btn btn-grouped' do
           = icon('trash-o')
           Delete
-      = link_to 'Cancel', namespace_project_issue_path(@project.namespace, @project, issuable), class: 'btn btn-grouped btn-cancel'
+      = link_to 'Cancel', polymorphic_path([@project.namespace.becomes(Namespace), @project, issuable]), class: 'btn btn-grouped btn-cancel'