Backport changes from gitlab-org/gitlab-ee!581 to CE.

!581 has a lot of changes that would cause merge conflicts if not
properly backported to CE. This commit/MR serves as a better
foundation for gitlab-org/gitlab-ee!581.

= Changes =

1. Move from `has_one {merge,push}_access_level` to `has_many`, with the
   `length` of the association limited to `1`. This is _effectively_ a
   `has_one` association, but should cause less conflicts with EE, which
   is set to `has_many`. This has a number of related changes in the
   views, specs, and factories.

2. Make `gon` variable loading more consistent (with EE!581) in the
   `ProtectedBranchesController`. Also use `::` to prefix the
   `ProtectedBranches` services, because this is required in EE.

3. Extract a `ProtectedBranchAccess` concern from the two access level
   models. This concern only has a single `humanize` method here, but
   will have more methods in EE.

4. Add `form_errors` to the protected branches creation form. This is
   not strictly required for EE compatibility, but was an oversight
   nonetheless.

1 files changed, 1 insertions, 17 deletions

diff --git a/app/services/protected_branches/create_service.rb b/app/services/protected_branches/create_service.rb
index 6150a2a83c9..a84e335340d 100644
--- a/app/services/protected_branches/create_service.rb
+++ b/app/services/protected_branches/create_service.rb
@@ -5,23 +5,7 @@ module ProtectedBranches
     def execute
       raise Gitlab::Access::AccessDeniedError unless can?(current_user, :admin_project, project)
 
-      protected_branch = project.protected_branches.new(params)
-
-      ProtectedBranch.transaction do
-        protected_branch.save!
-
-        if protected_branch.push_access_level.blank?
-          protected_branch.create_push_access_level!(access_level: Gitlab::Access::MASTER)
-        end
-
-        if protected_branch.merge_access_level.blank?
-          protected_branch.create_merge_access_level!(access_level: Gitlab::Access::MASTER)
-        end
-      end
-
-      protected_branch
-    rescue ActiveRecord::RecordInvalid
-      protected_branch
+      project.protected_branches.create(params)
     end
   end
 end