Reset merge status from mergeable MRs

Adds migrations to reset the merge_status of opened,
mergeable MRs. That's required by
https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/28513
so we're able to sync the status update along merge-ref,
without leaving MRs with a stale merge-ref.

1 files changed, 21 insertions, 0 deletions

diff --git a/db/migrate/20190530154715_add_index_to_merge_requests_state_and_merge_status.rb b/db/migrate/20190530154715_add_index_to_merge_requests_state_and_merge_status.rb
new file mode 100644
index 00000000000..e669f81ca35
--- /dev/null
+++ b/db/migrate/20190530154715_add_index_to_merge_requests_state_and_merge_status.rb
@@ -0,0 +1,21 @@
+# frozen_string_literal: true
+
+# See http://doc.gitlab.com/ce/development/migration_style_guide.html
+# for more information on how to write migrations for GitLab.
+
+class AddIndexToMergeRequestsStateAndMergeStatus < ActiveRecord::Migration[5.1]
+  include Gitlab::Database::MigrationHelpers
+
+  DOWNTIME = false
+
+  disable_ddl_transaction!
+
+  def up
+    add_concurrent_index :merge_requests, [:state, :merge_status],
+                         where: "state = 'opened' AND merge_status = 'can_be_merged'"
+  end
+
+  def down
+    remove_concurrent_index :merge_requests, [:state, :merge_status]
+  end
+end