Add a migration to update existing journals where updated_by_id points to a deleted user (#41572).

git-svn-id: https://svn.redmine.org/redmine/trunk@23170 e93f8b46-1217-0410-a6f0-8f06a7374b81

db/migrate/20241026031710_update_orphaned_journal_updated_by_id_to_anonymous.rb

@@ -0,0 +1,18 @@
+class UpdateOrphanedJournalUpdatedByIdToAnonymous < ActiveRecord::Migration[7.2]
+  def up
+    # Don't use `User.anonymous` here because it creates a new anonymous
+    # user if one doesn't exist yet.
+    anonymous_user_id = AnonymousUser.unscoped.pick(:id)
+    # The absence of an anonymous user implies a fresh installation.
+    return if anonymous_user_id.nil?
+
+    Journal.joins('LEFT JOIN users ON users.id = journals.updated_by_id')
+           .where.not(updated_by_id: nil)
+           .where(users: { id: nil })
+           .update_all(updated_by_id: anonymous_user_id)
+  end
+
+  def down
+    # no-op
+  end
+end