sd-bus: skip sending formatted UIDs via SASL
    
    The dbus external authentication takes as optional argument the UID the
    sender wants to authenticate as. This uid is purely optional. The
    AF_UNIX socket already conveys the same information through the
    auxiliary socket data, so we really don't have to provide that
    information.
    
    Unfortunately, there is no way to send empty arguments, since they are
    interpreted as "missing argument", which has a different meaning. The
    SASL negotiation thus changes from:
    
        AUTH EXTERNAL <uid>
        NEGOTIATE_UNIX_FD                   (optional)
        BEGIN
    
    to:
    
        AUTH EXTERNAL
        DATA
        NEGOTIATE_UNIX_FD                   (optional)
        BEGIN
    
    And thus the replies we expect as a client change from:
    
        OK <server-id>
        AGREE_UNIX_FD                       (optional)
    
    to:
    
        DATA
        OK <server-id>
        AGREE_UNIX_FD                       (optional)
    
    Since the old sd-bus server implementation used the wrong reply for
    "AUTH" requests that do not carry the arguments inlined, we decided to
    make sd-bus clients accept this as well. Hence, sd-bus now allows
    "OK <server-id>\r\n" replies instead of "DATA\r\n" replies.
    
    Signed-off-by: David Rheinsberg <david.rheinsberg@gmail.com>
    (cherry picked from commit 1ed4723d38cd0d1423c8fe650f90fa86007ddf55)
    
    Resolves: #1838081
    
    patch_name: 0402-sd-bus-skip-sending-formatted-UIDs-via-SASL.patch
    present_in_specfile: true
    location_in_specfile: 402
    squash_commits: true