[luatex] Kerning: when does it not work?

[Ulrike Fischer]

Am Thu, 5 May 2011 10:00:32 +0200 schrieb Ulrike Fischer:

> Am Thu, 5 May 2011 09:06:19 +0200 schrieb Heilmann, Till A.:
> 
>> Well, there are some problems with Paul's code, after all: The  
>> underscore character _ cannot be part of a URL *if* it occurs inside  
>> a footnote (see below). I have not checked for errors with other  
>> characters yet.
> 
> The \url command tries to adjust the catcodes (with the
> \let\do\makeother \dospecials line) but can't do it if the catcode
> is already fixed when used in the argument of another command. 
> 
> You can change the catcodetable additionally in the \setbox command:
> 
> \setbox\urlbox=\hbox{\directlua{tex.sprint(-2,"#1")}}%
> 
> It will need some testing to decide which catcode table is suitable
> (for the test I simply took -2 where everything has catcode 12).
> 
> But it will not solve all problems in \footnote: % and \ will still
> not work. So if you want to use url's in argument of other commands
> you will probably still need an \urldef-command like with the
> standard \url.

I think you will get away with most problems with

\def\url{%
    \begingroup
    \catcode`\%=12
    \URL
    }

\def\URL#1{%
    \setbox\urlbox=\hbox{%
     \directlua{%
      tex.sprint(-2,"\luatexluaescapestring{\unexpanded{#1}}")}}%
.....

You will still not be able to use a % in a footnote-url!

-- 
Ulrike Fischer