[Fontconfig] fontconfig not recognizing Luxi Mono as monospace

[Alan Coopersmith]

Behdad Esfahbod wrote:
> On 05/10/2010 07:13 PM, Alan Coopersmith wrote:
>> >From digging around, it seems like there's a glyph with an advance width
>> of 0 in luximr.ttf that fontconfig doesn't expect in this font which is
>> confusing it, and making it classify it as not monospaced.
>>
>> Is this a bug in fontconfig's monospace recognition or a bug in the font?
> 
> I'd say both.  Patch welcome.

Strangely, when trying to reproduce with a freshly updated git clone, it's
now the non-bold variants with spacing=100, and the bold ones failed to match.

By inserting a printf into FcFreeTypeCharSetAndSpacingForSize and running
fc-cache from git master, it's only finding characters with an advance of
1229 in luximr.ttf & luximri.ttf, but in luximb.ttf & luximbi.ttf it finds
4 each with an advance of 1338, and one with advance of 682:

 Glyph: 0x 175  Advance:   682

 Glyph: 0x  c4  Advance:  1338
 Glyph: 0x  c5  Advance:  1338
 Glyph: 0x  c2  Advance:  1338
 Glyph: 0x  c6  Advance:  1338

I'm not sure why these glyphs are different width, or what criteria fontconfig
should be using to decide they're not to be counted towards the spacing
calculation, so I can't suggest a fontconfig patch right now.

I can easily add a fonts.conf file to the X.Org fonts/bh-ttf package to override
it there though.

-- 
	-Alan Coopersmith-        alan.coopersmith at oracle.com
	 Oracle Solaris Platform Engineering: X Window System