[Fontconfig] Caching Postscript names

[Evgeniy Stepanov]

On Sunday 08 June 2008 16:03:39 Isaiah Beerbower wrote:
> On Thu, Jun 5, 2008 at 2:34 PM, Evgeniy Stepanov
>
> <eugeni.stepanov at gmail.com> wrote:
> > On Wednesday 04 June 2008 15:05:55 Isaiah Beerbower wrote:
> >> On 6/3/08, Isaiah Beerbower <public at ipaqah.com> wrote:
> >> > On Tue, Jun 3, 2008 at 3:28 PM, Keith Packard <keithp at keithp.com> 
wrote:
> >> >> On Tue, 2008-06-03 at 12:18 -0400, Isaiah Beerbower wrote:
> >> >>> I am working on GNUstep's (http://www.gnustep.org/) font support.
> >> >>> One of GNUstep's goals is to implement the OpenStep specification
> >> >>> (http://www.gnustep.org/resources/OpenStepSpec.pdf.gz). Fontconfig
> >> >>> is already being used by GNUstep, however, in order to properly
> >> >>> implement the OpenStep standard  the Postscript name should be used
> >> >>> to uniquely reference a font. Right now GNUstep is using the full
> >> >>> font name, however, it would be better if the Postscript name was
> >> >>> cached so that it could be used instead. So my final question is:
> >> >>> what are the pros and cons to adding the Postscript name to the
> >> >>> properties which Fontconfig caches?
> >> >>>
> >> >>> I've included a patch (below) which adds the functionality.
> >> >>
> >> >> That seems fine, however note that this won't let you search for
> >> >> fonts by postscript name. If you want to do that, you can modify the
> >> >> font matching code to look for postscript names in the pattern.
> >> >
> >> > Yes, I would want it to be searchable. I'll send a new patch as soon
> >> > as I have it ready.
> >>
> >> And here it is (attached).
> >
> > It does not work for me unless FC_POSTSCRIPT_NAME_OBJECT is added to the
> > end of the list. Not sure why, fc-match prints nothing and FC_DEBUG=2
> > shows a garbled font pattern. Maybe some other list has to be updated as
> > well? Anyway, the attached patch seems to work fine.
>
> Is it possible that the change breaks compatibility with existing
> caches? It works fine on my machine.

Yes, it was because of cache incompatibility.

Why does the global cache path in fonts.conf come before the one in user home 
directory? This way fc-cache from user account does absolutely nothing, cache 
files from .fontconfig are not even opened if there is a file with the same 
name in system directory.

> If this is the problem, I'm fine with the Postscript name being moved
> to the end of the list. I'll take a look, though, and make sure I
> didn't mis something.

Sure, even if both patches are correct, it is better to keep cache file 
compatibility.