Yes, I know that :-) , but it won't work, because xsl/koha-indexdefs-to-zebra.xsl  is probably wrongly coded.
So one of the aim of my patch was to be sure it needed to re-written.
My patch is signed off, so it the changes I made to biblio-zebra-indexdefs.xsl were probably right. That means koha-indexdefs-to-zebra.xsl  must probably be fixed to manage 1XX fieds.
But I want somebody to comment the bug to confirm it.