[Mediawiki-l] patch-backlinkindexes.sql

I received the following error while installing Mediawiki-1.9.3 while updating an existing database: Query "ALTER TABLE `imagelinks` DROP INDEX il_to, ADD INDEX il_to(il_to, il_from) " failed with error code "Specified key was too long. Max key length is 500 (mysql.ibiblio.org)". This coding appears to come from patch-backlinkindexes.sql ALTER TABLE /*$wgDBprefix*/pagelinks DROP INDEX pl_namespace, ADD INDEX pl_namespace(pl_namespace, pl_title, pl_from); ALTER TABLE /*$wgDBprefix*/templatelinks DROP INDEX tl_namespace, ADD INDEX tl_namespace(tl_namespace, tl_title, tl_from); ALTER TABLE /*$wgDBprefix*/imagelinks DROP INDEX il_to, ADD INDEX il_to(il_to, il_from); Any suggestions? Fred