sna: Prevent infinite recursion on udevless RRGetInfo()

As summarised by Mark Kettenis:

    Unfortunately commit 2c08d72393e4c8ddf5926571b087459aaa225cb1 that
    was made to resolve this bug introduced infinite recursion if
    polling udev for events fails (which is always the case on systems
    without udev).  The scenario is as follows:

    1. The server calls RRGetInfo().
    2. RRGetInfo() calls sna_randr_getinfo()
    3. sna_randr_getinfo() calls sna_uevent_poll(), which returns false
    4. sna_randr_getinfo() calls sna_mode_discover()
    5. sna_mode_discover() calls RRGetInfo()

    and we jump straight back to step 2, until we run out of stack
    space and crash

Reported-by: Mark Kettenis <kettenis@openbsd.org>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=91929#c8
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

0 files changed, 0 insertions, 0 deletions