As explained at:
http://www.collation-charts.org/articles/croatian.htm
this patch does more than just add support for Croatian UTF8 collation. It was based on Alexander's patch for mysql 5.1 (http://www.collation-charts.org/articles/utf8_croatian_ci.diff) and you could probably get it by pulling from mysql 6.
As explained at:
http:// www.collation- charts. org/articles/ croatian. htm
this patch does more than just add support for Croatian UTF8 collation. It was based on Alexander's patch for mysql 5.1 (http:// www.collation- charts. org/articles/ utf8_croatian_ ci.diff) and you could probably get it by pulling from mysql 6.