Bug#742767: TeX Gyre OpenType and wrongly(?) named glyphs

[Norbert Preining <preining@logic.at>]

Dear good friends from Poland,

here at Debian recently a problem surfaced with respect to the
OpenType TeX Gyre fonts.

The problem is that the ligatures are named
	f_i
etc while display engines like poppler, as well as the orginal
PostScript fonts, use
	fi
etc.

In Debian and Ubuntu, currently the TeX Gyre fonts provide the
*standard* postscript fonts, due to be considered generally 
better.

But that means, that at the current moment of one uses the TeX Gyre 
fonts as a replacement for the PS fonts, the ligatures will not be 
rendered at all. 

This was not the case originally, when we introduced that, but after 
some poppler upgrade the ligatures f_i etc are not accepted anymore.

Related bug reports are:
* Debian BTS: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=742767 
* FreeDesktop: https://bugs.freedesktop.org/show_bug.cgi?id=73291

Unfortunately the poppler maintainers do not seem to like to add
additional variants to be checked.

In the Debian bug report a renaming of glyph fontforge script
has been suggested, but trying that resulted in a very different
fonts (at least from the table sizes and total font size), so I 
am very reluctant to use this script. (See below for the core part)

Do you have any suggestion concerning this unfortunate situation?

I see a few options at the moment:
* Adapting the fonts from your side.
  This would be my preferred way, of course. But since I don't know
  any further implications, I cannot decide on that.

* Adapting the fonts on the Debian side:
  I don't want to do this, since we would have different fonts then
  the rest of the world, and that is not good.

* Dropping TeX Gyre as substitute for the PS fonts:
  The simplest option, but would hemper font quality rendering
  in many projects.

I would be very grateful if you could let me know your opinion.

All the best


Norbert


fontforge script core part:
    Select(0xFB00)
    SetGlyphName("ff")
    Select(0xFB01)
    SetGlyphName("fi")
    Select(0xFB02)
    SetGlyphName("fl")
    Select(0xFB03)
    SetGlyphName("ffi")
    Select(0xFB04)
    SetGlyphName("ffl")

------------------------------------------------------------------------
PREINING, Norbert                               http://www.preining.info
JAIST, Japan                                 TeX Live & Debian Developer
GPG: 0x860CDC13   fp: F7D8 A928 26E3 16A1 9FA0  ACF0 6CAC A448 860C DC13
------------------------------------------------------------------------