BDF 2.1 fonts not loading in Xorg 1.20

[Adam Jackson]

On Thu, 2019-09-12 at 16:42 -0400, Aaron Caraveo wrote:
> We have an enterprise system that’s using BDF fonts in version 2.1
> format.  Xorg 1.17.x in RHEL 7.2 would load the fonts fine, but Xorg
> 1.20.x in RHEL 7.6 fails to load the fonts.  There are no errors in
> the Xorg output (we increased the verbosity) and nothing in the
> system logs.  Is this a known issue with Xorg 1.20.x?

For each point release between 7.2 and 7.6:

7.3: xserver from 1.17.2-10 to -22
7.4: libXfont from 1.5.1-2 to 1.5.2-1; new libXfont2 2.0.1-2; xserver
to 1.19.3-11
7.5: xserver to 1.19.5-5
7.6: libXfont to 1.5.4-1, libXfont2 to 2.0.3-1, xserver to 1.20.103

7.4 introduced libXfont2 and xserver began using it, due to a major API
redesign that was required for xserver to change to using epoll
internally. However we still provides builds of (and CVE fixes for)
libXfont for ABI compatibility. Most of xserver's bitmap font handling
lives in libXfont (either version), so the most likely explanation is
that the bug lives there. And (other than the above API change) the
font library is essentially only ever changed for security fixes, so
it's possible your fonts are sensitive to those changes.

I don't think there was anything font-related that changed at all in
7.3's xserver, so the first thing I would try is to take an otherwise
7.2 system and see if updating libXfont to the version from 7.4 or 7.6
shows the same error.

If that showed no change, then I'd start with a 7.4 system and see if
that exhibits the problem; then update libXfont2 to the version from
7.6 and see if _that_ exhibits the problem.

- ajax