Fix 500 errors with legacy appearance logos

Prior to GitLab 9.0, attachments were not tracked the `uploads` table,
so it was possible that the appearance logos were just stored in the
database as a string and mounted via CarrierWave.

https://gitlab.com/gitlab-org/gitlab-ce/issues/29240 implemented in
GitLab 10.3 was supposed to cover populating the `uploads` table for all
attachments, including all the logos from appearances. However, it's
possible that didn't work for logos or the `uploads` entry was orphaned.

GitLab instances that had a customized logo with no associated `uploads`
entry would see Error 500s. The only way to fix this is to delete the
`logo` column from the `appearances` table and re-upload the attachment.

This change makes things more robust by falling back to the original
behavior if the upload is not available.

This is a CE backport of
https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/9277.

Closes https://gitlab.com/gitlab-org/gitlab-ee/issues/9357

1 files changed, 7 insertions, 0 deletions

diff --git a/spec/models/appearance_spec.rb b/spec/models/appearance_spec.rb
index ec2e7d672f0..cc76a2019ec 100644
--- a/spec/models/appearance_spec.rb
+++ b/spec/models/appearance_spec.rb
@@ -36,6 +36,13 @@ describe Appearance do
       expect(subject.send("#{logo_type}_path")).to be_nil
     end
 
+    it 'returns the path when the upload has been orphaned' do
+      appearance.send(logo_type).upload.destroy
+      appearance.reload
+
+      expect(appearance.send("#{logo_type}_path")).to eq(expected_path)
+    end
+
     it 'returns a local path using the system route' do
       expect(appearance.send("#{logo_type}_path")).to eq(expected_path)
     end