[XeTeX] Strangeness with Minion Pro Opticals Small Caps

[Jonathan Kew]

On 20 Aug 2006, at 10:43 am, Will Robertson wrote:

> On 20/08/2006, at 19:04 , Peter Heslin wrote:
>
>>> If I'm right, it's not an "incompatible font situation", it's a  
>>> badly-
>>> programmed GSUB table -- which xetex can't realistically detect, as
>>> it can't know what the font designer intended. It just follows the
>>> rules.
>>
>> Definitely.  I'm just surprised that such a widely-distributed font
>> version has such a major error.
>
> Maybe it's on purpose and Reader is programmed to work around it --  
> essentially a form of copy protection?

No (at least I don't believe so). But Reader won't be using the GSUB  
table, as PDF documents represent the text directly by glyph index.  
So you'd only encounter the bug if you extract the font from Reader  
and install it for an OT-Layout-aware app to use -- not something the  
average user is likely to do.

It's also possible that some OpenType-aware apps avoid the bug by  
overriding the order of lookups in the font, and applying them in a  
sequence that they consider "standard". That could mask the error in  
the font, but deviates from the published OT specification.

JK