Re: [Freefont-bugs] ligatures

[Steve White]

On Feb 16, 2008 2:03 AM, Karl Berry <address@hidden> wrote:
>     I mean, what applications make use of the automatic replacement of
>     strings by ligatures?
>
> TeX does, certainly.
>
TeX does, and big page-layout programs do.

But...these, I think, have their own internal idea of which replacements to do.

What applications make use of these tables we have been discussing to
make that determination?

I have recently seen an unfortunate ligature appear all over the place
because it was in one of these.  It was a conjoined 'st' ligature in
FreeSerif. It was a bug and was fixed by taking it and other ligtures
out of the obligatory table, but now I realize the 'ffi' etc also
aren't being replaced, although they are discretionary.

It looks like many apps that will do obligatory replacements, simply
ignore the discretionary ones. I guess I'll have to do some
experiments.

That would be a pity.  If the user of the application wants to insert
a ligature by hand, they can always do that. If the app doesn't use
the discretionary table, who does?

Could it be there is no standard policy as to how apps should handle
these tables?