Subject: bug#18637: 24.4.50; doc of frame parameter DISPLAY vs actual value on MS Windows

From: Drew Adams <[email-masked]>
Date: Sun, 5 Oct 2014 19:55:48 -0700 (PDT)

> > > In (elisp) `Basic Parameters' I see this description of frame
> > > parameter `display':
> > >
> > >   The display on which to open this frame.  It should be a
> > >   string of the form `"HOST:DPY.SCREEN"', just like the
> > >   `DISPLAY' environment variable.
> 
> Btw, this is not the best place in the manual to read about this.
> A better one is "Multiple Terminals", where it says explicitly
> that this is only relevant on X.  The index entry "displays,
> multiple" leads to that node.

As a matter of fact, that is the node I started with, when trying
to find out about such things.  Please see this help-gnu-emacs
thread, where I mention that node and provide some context.
http://lists.gnu.org/archive/html/help-gnu-emacs/2014-10/msg00099.html

Is there no support for multiple monitors on MS Windows?  That's
really what I was looking for info about, along with general info
about Emacs display on multiple monitors.  When looking, I came
across the doc for `display-monitor-attributes-list' and
`frame-monitor-attributes'.

I was not able to find out how to obtain info about which monitor
is being used to show a particular frame, or how to specify
which monitor to use to display a particular frame.

The symptom reported was that by modifying a frame's parameters
to restore its previous values of `top', `left', `width' and
`height', the frame got moved to another monitor, for some
reason.

I don't have multiple monitors, to try things out, but I was
looking for some info in the manual that might explain what the
OP reports.