Missing frame parameters on tty's

[Alan Mackenzie <acm@muc.de>]

Hello, Emacs.

In my initial investigation of bug #19706, an immediate cause of the
failure is clear - `frameset-move-onscreen' executes:

    (frame-parameter frame 'left)

, but on a tty this parameter is nil.  This is insanity, and was an
accident waiting to happen (it has now happened).

The correct values of frame parameters 'left and 'top on a tty cannot be
other than 0.

There are two ways of fixing bug #19706:

The first is to put in special case handling for missing frame
parameters, pray that the same error isn't already programmed into our
source anywhere else, and trust our highly skilled hackers never to
blunder into the same trap again.

The second is to set the frame parameters appropriately for tty's.

I think I've made it obvious which course I prefer.

-- 
Alan Mackenzie (Nuremberg, Germany).