[lltx] Problem with slanted fonts

[Ulrike Fischer]

Am Sun, 19 Sep 2010 14:37:31 +0300 schrieb Khaled Hosny:

> On Sun, Sep 19, 2010 at 01:27:38PM +0200, Ulrike Fischer wrote:
>> Am Sat, 18 Sep 2010 15:58:37 +0930 schrieb Will Robertson:
>> 
>> 
>>>>> I have installed TexLive 2010 and am trying out Lualatex.
>>>>> When typesetting the following example:
>>>>> 
>>>>> \documentclass{article}
>>>>> \usepackage{fontspec}
>>>>> \setmainfont{Gentium Basic}
>>>>> \begin{document}
>>>>> \textsl{hello}
>>>>> \end{document}
>>>>> 
>>>>> the resulting pdf file contains the following line:
>>>>> 
>>>>> Basic/I:mode=node;script=latn;language=DFLT;hello
>>>>> 
>>>>> I wouldn't expect to find the font features in there...
>>>>> What am I doing wrong here?
>>>> 
>>>> Nothing. It is a bug, due to the space in the font name. 
>>>> 
>>>> Until the bug is repaired you can remove the space from the font
>>>> name (GentiumBasic), or you can use \textit instead of \textsl. This
>>>> will give the same result anyway as long as you don't use the
>>>> SlantedFont-option to declare a specific slanted font. 
>>  
>>> I've been trying to track down the origin of this bug and so far
>>> I'm out of luck. 
>> 
>> I have tracked it a bit down. The source is 1. that \slshape use sub
>> in \DeclareFontShape and 2. that the "font declaration" is stored in
>> a command. The result depends also on the actual font. In the
>> following example Times New Roman gives "only" some unwanted text in
>> the pdf (because "Times" is the name of an existing font too), while
>> Lucida gives directly an error (! Font
>> \EU2/testfam/m/n/10=name:Lucida not loadable:). Attention: If you
>> use both method (with and without command \fontdesc) for the same
>> font they can be side effect.
> 
> So, how XeTeX is dealing with this? If its behaviour can be emulated in
> luaotfload then we should do it, else it might be something for LuaTeX
> to handle.

I have no idea how xetex is going around. But I found the place
where it fails: in \do at subst@correction. A failing example gives
this with tracingmacros =1 :


EU2/testfam/m/n -><->"name:Lucida Sans" 

<->"name:Lucida Sans" ->

\subst at correction ->\EU2/testfam/m/it/10 \global \font
\EU2/testfam/m/n/10 \fontname \font \relax 
luaotfload | Updating the font names database:
luaotfload | Scanning TEXMF and OS fonts...
... and then error

A non failing shows this (notice the missing space!):

EU2/testfam/m/n -><->"name:LucidaSans" 

<->"name:LucidaSans" ->

\subst at correction ->\EU2/testfam/m/it/10 \global \font
\EU2/testfam/m/n/10 \fontname \font \relax 
luaotfload | load font: font family='lucidasans',
subfamily='regular' found: lsans.ttf
 
-- 
Ulrike Fischer