Re: [ft] Issues with fonts embedded in PDF

[Derek B. Noonburg]

On 28 Jan, Werner LEMBERG wrote:
> 
>> Our test file
>> (http://www.intelsig.be/~piater/nobackup/fop/fop-trunk.pdf) contains
>> eight embedded TrueType fonts, and is displayed correctly by
>> Acroread. However, four of these fonts (FreeSerif, latex-xft cmr10,
>> LinuxLibertine, STIXGeneral converted from OTF using fontforge) just
>> leave blanks when viewed by xpdf, gv, kpdf, or evince (but
>> copy&paste ok); the other four are rendered ok (BitstreamVeraSerif,
>> DejaVuSerif, LiberationSerif, GentiumBasic).
> 
> xpdf reports `cid2' loading failures, whatever this is.  Note that
> xpdf and friends all use the xpdf library, AFAIK.
> 
>> Since all of these four viewers use FreeType, it looks like it might
>> be a FreeType issue; on the other hand, all of these fonts are
>> displayed correctly by ftview. Or perhaps it is an embedding (Fop)
>> issue, but acroread has no trouble.
> 
> I suspect a problem with CID handling.

The TrueType fonts in question have broken table directories.  In
particular:

* the numTables entry is incorrect (one too high)
* the last entry in the table directory has a valid tag, but the rest of
  the entry is all zeros
* I believe searchRange entry is also wrong (but I'm not sure that
  anyone uses this anymore, so it may not be relevant)

(That's for the embedded copy of FreeSerif -- I didn't look at the
others.)

I had another report of this problem a month or two ago.  It seems to be
a bug in FontForge.  In that case, someone was converting metafont fonts
to TrueType, using mftrace, which uses FontForge.

If you've already tried the latest version of FontForge, I would suggest
reporting the bug to them.  Please feel free to forward this message,
and they're welcome to contact me if they have questions on the info
above.

- Derek