[XeTeX] [tex-live] Problem with ocrb10.otf ligature 'fi'

[Pander]

On 2011-06-13 15:27, Zdenek Wagner wrote:
> 2011/6/13 Pander <pander at users.sourceforge.net>:
>> TeX Live list members: see full thread here:
>> http://tug.org/pipermail/xetex/2011-June/020681.html for now keep the
>> discussion at XeTeX's list.
>>
>> On 2011-06-13 14:22, mskala at ansuz.sooke.bc.ca wrote:
>>> On Mon, 13 Jun 2011, Pander wrote:
>>>> TeX Live 2010
>>>>
>>>> /usr/local/texlive/2010/texmf-dist/fonts/opentype/public/ocr-b-outline/ocrb10.otf
>>>
>>> That is Zdeněk Wagner's auto-conversion of Norbert Schwarz's Metafont
>>> source.  It doesn't contain f-ligatures no matter what the GSUB table may
>>> say.  I took a look at it with Fontforge and I see that it contains a GSUB
>>> table pointing the ligatures at "alternate" and added non-ASCII characters
>>> from the Schwarz version, some of which happen to be ligature-like but not
>>> the correct ones.  For instance, "fl" points at the Æ glyph.
>>>
>>> I recogize that pattern because it happened in an earlier version of my
>>> own version of the font, as a result of auto-conversion.  The thing is,
>>> Schwarz's Metafont files used a nonstandard custom encoding.  If you
>>> simply convert the font code point for code point to whatever the default
>>> 8-bit Adobe encoding might be, you end up with Schwarz's extra glyphs at
>>> the "f-ligature" code points (as well as some distortions at quotation
>>> mark, dotless i and j, and similar code points).  The existence of a GSUB
>>> table pointing at those points can probably be explained by defaults from
>>> the auto-conversion.  So in summary, yes, it's a bug in the font.
>>
>> Could the conversion software generate a warning when it recognises such
>> a situation?
>>
> The fonts were first converted to PFB by mftrace, then opened in
> FontForge and saved as OTF. No warning was displayed.

Sorry, I mean, should those software packages be improved to generate
warnings for these kind of situations to prevent it in the future?