bug#800: multi-tty suspend confusion

[Glenn Morris]

Chong Yidong wrote:

>> ./src/emacs -Q -nw --eval "(server-start)"
>> 
>> From another xterm:
>> 
>> ./lib-src/emacsclient -c README
>> 
>> Now C-z in the "emacs -nw" frame reports:
>> 
>> "Suspending an Emacs running under X makes no sense"
>> 
>> It continues to do so even after the X frame is closed.

> I've checked in a fix.

Now it works after the X frame is closed, but shouldn't it also be
possible to suspend from the terminal frame while the X frame is open?