xdm writes to /var/run/utmp

[Andrew Lankford]

Does anyone know why xdm writes to /var/run/utmp on its own without even 
using sessreg in it Xstartup or similar configuration files (contrary to 
what the man page says)?  Perhaps some people think that having this 
sort of line in the output of who utility as being useful:

  andrew         :0       Nov 12 20:15

I don't, because it confuses other utilties like wall:

wall: /dev/:0: No such file or directory

...and both sessreg and the +ut option for *term work just great (if you 
want them).  So why do it, and how can you disable it short of 
commenting out the offending source code every time I want to upgrade?

Andrew Lankford