[Fontconfig] The "No fonts found" error - a culprit?

[Keith Packard]

Around 12 o'clock on Feb 27, Peter Chapman wrote:

>	No fonts found; this probably means that the fontconfig
>	library is not correctly configured. You may need to edit
>	the fonts.conf configuration file. More information about
>	fontconfig can be found in the fontconfig(3) manual
>	page and on http://fontconfig.prg

I fixed a problem related to this last night.  As you uncovered, 
fontconfig bails out of matching when it discovers any inconsistencies in 
the internal state of fonts.  To save memory, font state is shared across 
fonts at many levels, one of the levels is that identical lists of values 
are stored as a single value list.  In the case uncovered last night, one 
font had a list containing the value '6.0' and another with the value '6'.
The 'identical' test said those were the same, but the matching code
didn't allow floating point values where integers were required, so it 
bailed out.  That fix was easy, but I'm going to go back and consider how 
to best deal with fonts that don't conform to the matchers expectations.

-keith