Hi Thanh,
I think it was not a good decision to introduce those new features, as they touch a very sensitive area of tex and it's hard to get them right. I wonder whether it is better to discard them all.
removing them is tricky since they may be in use already but don't spend to much time on fixing things that are hard to fix in current tex; once luatex is in a state where fontdata has no longer the global properties and where we can have more control over font related featurss, you can probably rewrite most of the code in a cleaner way Hans ----------------------------------------------------------------- Hans Hagen | PRAGMA ADE Ridderstraat 27 | 8061 GH Hasselt | The Netherlands tel: 038 477 53 69 | fax: 038 477 53 74 | www.pragma-ade.com | www.pragma-pod.nl -----------------------------------------------------------------