Merge branch 'issue_14671' into 'master'

Fix cancel button on issuables

Fixes #14671

See merge request !3417
Signed-off-by: Rémy Coutable <remy@rymai.me>

CHANGELOG

@@ -16,7 +16,7 @@ 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
+  - Fix error 500 with cancel button on issuable edit form. !3392 + !3417
   - Fix background when editing a highlighted note. !3423
   - Remove tabstop from the WIP toggle links. !3426
   - Ensure private project snippets are not viewable by unauthorized people.

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

@@ -127,7 +127,7 @@
       for this project.
 
   - if issuable.new_record?
-    = link_to 'Cancel', polymorphic_path([@project.namespace, @project, issuable.class]), class: 'btn btn-cancel'
+    = link_to 'Cancel', polymorphic_path([@project.namespace.becomes(Namespace), @project, issuable.class]), class: 'btn btn-cancel'
   - else
     .pull-right
       - if current_user.can?(:"destroy_#{issuable.to_ability_name}", @project)