This finishes the procedure for migrating events from the old format
into the new format. Code no longer uses the old setup and the database
tables used during the migration process are swapped, with the old table
being dropped.
While the database migration can be reversed this will 1) take a lot of
time as data has to be coped around 2) won't restore data in the
"events.data" column as we have no way of restoring this.
Fixes https://gitlab.com/gitlab-org/gitlab-ce/issues/37241
This adds an ID-less table containing one row per file, per merge request
diff. It has a column for each attribute on Gitlab::Git::Diff that is serialised
currently, with the advantage that we can easily query the attributes of this
new table.
It does not migrate existing data, so we have fallback code when the legacy
st_diffs column is present instead. For a merge request diff to be valid, it
should have at most one of:
* Rows in this new table, with the correct merge_request_diff_id.
* A non-NULL st_diffs column.
It may have neither, if the diff is empty.
* Regenerates tokens for all models that have them
* Remove variables, since they are basically just storing encrypted data
* Bumped version up to 0.1.6
* Updated related docs
