[Fontconfig] Pattern Matching Issues

[Behdad Esfahbod]

On 14-01-30 09:26 PM, Akira TAGOH wrote:
> On Fri, Jan 31, 2014 at 4:27 AM, Behdad Esfahbod <behdad at behdad.org> wrote:
>> The problem is that in fcfreetype.c, we only set FC_SPACING on the font if
>> it's not FC_PROPORTIONAL.  Then when matching, if the font pattern doesn't
>> have FC_SPACING, it is an implicit match.  Ouch!  I think we should fix the
>> first part.  I'm sure there was a reason for it (broken fonts, etc?).  But I
>> think we should fix it now.  Here's the relevant part of fcfreetype.c:
>>
>>     if (spacing != FC_PROPORTIONAL)
>>         if (!FcPatternAddInteger (pat, FC_SPACING, spacing))
>>             goto bail2;
> 
> The reason may be true. but I have no idea what the font it was. we
> may need to figure out the side-effect on this change in advance.
> Aside from that, we should add a test case to check if targeted
> parameters on matcher is surely available after scanning. or having a
> trick for those missing parameters on matcher and ignore it. later one
> might be more robust for incompatibility on matcher in the future
> perhaps.

Sure that would be good long term.  But in this case, not setting
FC_PROPORTIONAL totally breaks any use of this property.

Indeed, we want to be able to match monospace fonts.  We should do that in vte
for example.


-- 
behdad
http://behdad.org/