1 files changed, 55 insertions, 0 deletions
diff --git a/db/migrate/20180201145907_migrate_remaining_issues_closed_at.rb b/db/migrate/20180201145907_migrate_remaining_issues_closed_at.rb
new file mode 100644
index 00000000000..5a36dec6a9a
--- /dev/null
+++ b/db/migrate/20180201145907_migrate_remaining_issues_closed_at.rb
@@ -0,0 +1,55 @@
+# See http://doc.gitlab.com/ce/development/migration_style_guide.html
+# for more information on how to write migrations for GitLab.
+
+class MigrateRemainingIssuesClosedAt < ActiveRecord::Migration
+  include Gitlab::Database::MigrationHelpers
+
+  # Set this constant to true if this migration requires downtime.
+  DOWNTIME = false
+
+  disable_ddl_transaction!
+
+  class Issue < ActiveRecord::Base
+    self.table_name = 'issues'
+    include EachBatch
+  end
+
+  def up
+    Gitlab::BackgroundMigration.steal('CopyColumn')
+    Gitlab::BackgroundMigration.steal('CleanupConcurrentTypeChange')
+
+    if migrate_column_type?
+      if closed_at_for_type_change_exists?
+        migrate_remaining_rows
+      else
+        # Due to some EE merge problems some environments may not have the
+        # "closed_at_for_type_change" column. If this is the case we have no
+        # other option than to migrate the data _right now_.
+        change_column_type_concurrently(:issues, :closed_at, :datetime_with_timezone)
+        cleanup_concurrent_column_type_change(:issues, :closed_at)
+      end
+    end
+  end
+
+  def down
+    # Previous migrations already revert the changes made here.
+  end
+
+  def migrate_remaining_rows
+    Issue.where('closed_at_for_type_change IS NULL AND closed_at IS NOT NULL').each_batch do |batch|
+      batch.update_all('closed_at_for_type_change = closed_at')
+    end
+
+    cleanup_concurrent_column_type_change(:issues, :closed_at)
+  end
+
+  def migrate_column_type?
+    # Some environments may have already executed the previous version of this
+    # migration, thus we don't need to migrate those environments again.
+    column_for('issues', 'closed_at').type == :datetime # rubocop:disable Migration/Datetime
+  end
+
+  def closed_at_for_type_change_exists?
+    columns('issues').any? { |col| col.name == 'closed_at_for_type_change' }
+  end
+end