[BUG] TRAMP 2.1.20: "uudecode -o /dev/stdout" check

[Dmitry Kurochkin]

Hello.

I am using TRAMP 2.1.20 in Emacs 23.3.  Usually it is all smooth and
cool.  But recently I got a new embedded system to play with - a
satellite receiver Vu+DUO.  I am accessing the system through dropbear
ssh.  TRAMP reads files just fine.  And clames to successfully save
files as well.  But in fact it saves empty files.  It can be very
surprising to find an empty config file after you have just saved it in
Emacs :)

Turns out TRAMP uses "uudecode -o /dev/stdout" method for remote
decoding.  But there is no /dev/stdout device (or symlink) on the
system.  Since everything is running under root (yes, this is bad),
uuencode just creates a regular file /dev/stdout and writes the output
to it, while stdout (where TRAMP expects the output) is empty.  I think
a simple solution would be to test that /dev/stdout exists and is a
character device (i.e. "test -c /dev/stdout") before trying to do
"uudecode -o /dev/stdout".

I can provide additional info or do testing if needed.

Please keep me in Cc as I am not on the list.

Regards,
  Dmitry