Bug#909750: applications tries to write to /usr/* directories via libfontconfig1

[Chris Hofstaedtler]

* Thierry Fauck at linux.ibm.com <thierry at linux.ibm.com> [190406 14:35]:
> > >The only occurrence I'm seeing on my system is:
> > >
> > >openat(AT_FDCWD, "/usr/lib/firefox/fonts/.uuid.TMP-EWjEq0", O_RDWR|O_CREAT|O_EXCL|O_CLOEXEC, 0600) = -1 EACCES (Permission denied)
> > 
> > Now it's the only occurrence for me, too.
> > 
> 
> With current packages I don't see any more issues of openat(....)
> EACESS(...) when tracing firefox-bin

With libfontconfig1:amd64 2.13.1-2:

$ strace -o '| grep -w EACCES' /usr/lib/firefox-esr/firefox-bin
openat(AT_FDCWD, "/usr/lib/firefox-esr/fonts/.uuid.TMP-pZnI7N", O_RDWR|O_CREAT|O_EXCL|O_CLOEXEC, 0600) = -1 EACCES (Permission denied)

C.