The function "smb_mkstemp()" in "lib/util.c", which opens a temporary file,
does not use the Samba VFS API: it direcly calls "mkstemp" or "mktemp"
As a consequence, a VFS module which implements "opaque" Samba VFS calls, to
provide a virtual file system, would not be able to manage "SMBctemp" messages.
As far as I am concerned, I have no real need to support "SMBctemp" in my
virtual file system, I just report the bug in case it would break other VFS
Please retest against a current release and reopen if the issue still exists.