bug#12125: emacsclient should work like "emacsclient -t" when $DISPLAY is not set

[Chong Yidong]

Dan Nicolaescu <dann@gnu.org> writes:

> When connecting to a host which runs "emacs --daemon" with "ssh -x"
> (so $DISPLAY is not set)
>
> $ emacsclient FILENAME 
>
> says "Waiting for Emacs..." and does not open any frame.
>
> It should instead work like "emacsclient -t FILENAME" and open a
> terminal frame.

Hmm, according to the code in emacsclient.c, emacsclient should already
do the right thing when DISPLAY is not set.  And I verified this by
doing 

$ export DISPLAY=""
$ emacsclient -c FILENAME

=> FILENAME is opened in the terminal.