[Fontconfig] Application startup performance

[u-pnrz at aetey.se]

On Mon, Jan 11, 2016 at 11:59:26AM +0000, Nick Alcock wrote:
> > If readdir is getting called at each application startup, there's a
> > problem with the caching mechanisms in fontconfig that should get fixed.
> 
> Oh, readdir() is nothing. At the moment, *stat()* is getting called for

+1

> I'd be quite happy if it just updated the cache only for directories
> under ~ or directories the user had permission to write to.

+1 for permissions,
(a heuristics like ~ is hardly general enough to be reliable)

If a permission check will be applied, then please with access() not
mode bits.

As soon as there are ACLs on the file system, the mode bits are broken
and plainly "wrong". We heavily rely on proper ACLs on file systems,
software that tries to interpret mode bits is then totally unusable
without patching, that's why I mention this.

Regards,
Rune