samba - Aug 2008 - Re: chdir (/root/tmp) failed - but why is it trying?

Back in April I posted this.  No-one replied.

 > I'm seeing this in the log.smbd file for v3.0.28a.
 >
 > [2008/04/14 18:29:16, 0] smbd/service.c:set_current_service(184)
 >    chdir (/root/tmp) failed
 >
 > This happens straight after a server startup if I connect to my HOME
 > directory (and I'm the only person using the server).  It is noted in
 > the log (debug level 1) *before* the entry about me connecting to my
 > home.
 >
 > There is no mention of /root (or any tmp) in the config file.

Well - I've found out the reason.  On the system in question 
(Mandriva2007) TMPDIR is set to ~/tmp on login, and I was starting Samba 
from the command line (rather than as a service at boot time).  When I 
unset TMPDIR in the startup script all is OK.

Not sure why Samba decides to chdir to TMPDIR (or rather, to the result 
from tmpdir() in lib/util.c) when being queried for IPC$ (?), which 
seems to be what is happening ("real" connexions worked OK - it was
just
the behind-the-scenes one that failed).  But letting this default to 
/tmp lets things roll OK.