Prevent EE backport migrations from running if CE is not migrated
If a user upgraded to any GitLab 11.x EE version but switched back to CE, it's possible the state of the EE tables are not in the right state for the EE backport migration to work properly. In particular, there were three tables that had trouble:
The EE backport migration would fail while trying to add foreign key constraints because a key didn't exist in the table. This happens because any EE migration that add or removed columns between v11.0.0 and v11.11.3 are not guaranteed to be applied in an CE installation. The EE backport schema does not individually backport these migrations.
We now check if certain columns are present to determine whether the backport migration is in the proper state. CE users are required to upgrade to v11.11.3 EE if they ever installed EE previously before they can go back to v12.x CE.
git checkout -f v11.0.0-ee bundle exec rake db:reset git checkout .; git checkout -f v11.11.3 bundle exec rake db:migrate git checkout .; git checkout -f v12.0.0 bundle exec rake db:migrate