In the event that database format upgrade fails because row data cannot be unserialized, the script errors fatally. Additional error handling is needed, or perhaps detection of row format to determine if the row data has already been upgraded.
Related Gerrit Patches:
|mediawiki/extensions/OATHAuth : master||Suppress unserialize errors|
MediaWiki\suppressWarnings(); $scratchTokens = unserialize( base64_decode( $row->scratch_tokens ) ); MediaWiki\restoreWarnings();
would be enough to stop the noise, but isn't really checking for whether things are already migrated