The need to drop index patch-rename-iwl_prefix.sql arose from development versions that had discrepancies between tables.sql and updater. Let's just DROP IF EXISTS it.
-- installs if they ran update.php between it being added and being renamed
--
-DROP INDEX /*i*/iwl_prefix_from_title ON /*_*/iwlinks;
+DROP INDEX /*i*/iwl_prefix_from_title;
-- installs if they ran update.php between it being added and being renamed
--
-DROP INDEX /*i*/iwl_prefix ON /*_*/iwlinks;
+DROP INDEX /*i*/iwl_prefix;
--
-- Recreates the iwl_prefix for the iwlinks table
--
-DROP INDEX /*i*/iwl_prefix;
+DROP INDEX IF EXISTS /*i*/iwl_prefix;
CREATE INDEX /*i*/iwl_prefix_from_title ON /*_*/iwlinks (iwl_prefix, iwl_from, iwl_title);
\ No newline at end of file