Only show a pull mirror if mirroring is actually enabled

Prior to GitLab 11.11, a pull mirror would only be shown if the project
had the `mirror` flag enabled.

After https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/10361, a
pull mirror would be shown if import data were available. However,
projects can have import data but not be mirrors. Since import data only
gets deleted if the project were a mirror before, it became impossible
to remove a pull mirror from the interface.

This change reverts to the previous behavior for pull mirrors. Push
mirrors retain the same behavior as before.

Closes https://gitlab.com/gitlab-org/gitlab-ee/issues/12871

ee/app/views/projects/mirrors/_table_pull_row.html.haml

+// There's no way to disable or enable a pull mirror, so if the boolean
+// isn't set, then we don't have a pull mirror.
+- return unless @project.mirror?
+
 - import_state = @project.import_state
-- disabled_mirror = !@project.mirror?
 
 - return unless import_state
 
-%tr{ class: ('bg-secondary' if disabled_mirror) }
+%tr
   %td.mirror-url= @project.safe_import_url
   %td= _('Pull')
   %td= import_state.last_update_at.present? ? time_ago_with_tooltip(import_state.last_update_at) : _('Never')
   %td
-    - if disabled_mirror
-      = render 'projects/mirrors/disabled_mirror_badge'
     - if import_state&.last_error.present?
       .badge.badge-danger{ data: { toggle: 'tooltip', html: 'true' }, title: html_escape(import_state.last_error.try(:strip)) }= _('Error')
   %td.mirror-action-buttons
     .btn-group.mirror-actions-group.pull-right{ role: 'group' }
-      - if @project.mirror?
-        - ssh_public_key = @project.import_data.ssh_public_key
-        - if ssh_public_key
-          = clipboard_button(text: ssh_public_key, class: 'btn btn-default qa-copy-ssh-public-key', title: _('Copy SSH public key'))
-        - if import_state.mirror_update_due? || import_state.updating_mirror?
-          %button.btn.disabled{ type: 'button', data: { container: 'body', toggle: 'tooltip' }, title: _('Updating') }= icon("refresh spin")
-        - else
-          = link_to update_now_project_mirror_path(@project), method: :post, class: 'btn js-force-update-mirror', data: { container: 'body', toggle: 'tooltip' }, title: _('Update now') do
-            = icon("refresh")
+      - ssh_public_key = @project.import_data.ssh_public_key
+      - if ssh_public_key
+        = clipboard_button(text: ssh_public_key, class: 'btn btn-default qa-copy-ssh-public-key', title: _('Copy SSH public key'))
+      - if import_state.mirror_update_due? || import_state.updating_mirror?
+        %button.btn.disabled{ type: 'button', data: { container: 'body', toggle: 'tooltip' }, title: _('Updating') }= icon("refresh spin")
+      - else
+        = link_to update_now_project_mirror_path(@project), method: :post, class: 'btn js-force-update-mirror', data: { container: 'body', toggle: 'tooltip' }, title: _('Update now') do
+          = icon("refresh")
       %button.js-delete-mirror.js-delete-pull-mirror.btn.btn-danger{ type: 'button', data: { toggle: 'tooltip', container: 'body' }, title: _('Remove') }= icon('trash-o')

ee/changelogs/unreleased/sh-hide-disabled-pull-mirrors.yml

+---
+title: Only show a pull mirror if mirroring is actually enabled
+merge_request: 15049
+author:
+type: fixed

ee/spec/features/projects/settings/ee/repository_mirrors_settings_spec.rb

@@ -81,5 +81,23 @@ describe 'Project settings > [EE] repository' do
         expect(mirrored_project).not_to be_mirror
       end
     end
+
+    context 'with a non-mirrored imported project', :js do
+      let(:external_project) do
+        create(:project_empty_repo,
+               import_url: "https://12345@github.com/testngalog2/newrepository.git")
+      end
+
+      before do
+        external_project.add_maintainer(user)
+      end
+
+      it 'does not show a pull mirror' do
+        visit project_settings_repository_path(external_project)
+
+        expect(page).to have_selector('.js-delete-mirror', count: 0)
+        expect(page).to have_select('Mirror direction', options: %w[Pull Push])
+      end
+    end
   end
 end