bug#21415: 25.0.50; Emacs Trunk -- pixelwise width/height for x-create-frame

[martin rudalics]

> I just checked this against Emacs 24.5. In that version, new frames always
> start at 0 x 0, no matter how high they are. In addition, both versions
> seem to react to the `top' property -- in Emacs 24 the window is placed
> relative to the top (as expected). In Emacs 25 the start position when the
> parameter is missing or is zero places the bottom of the frame in the
> middle-ish of the screen, and a positive value for `top' places it further
> down on the screen.
>
> I would suggest that we try to find why Emacs 24 and 25 differs, so we can
> revert back to the old behaviour.

Agreed.  Could you or Keith please do that?  No OS X around here.

> A side topic: The documentation to `make-frame' seems a little bit vague.
> It doesn't include `top' as an attribute, on the other hand doesn't say
> that it accepts more properties than the ones listed.

We don't mention most of the parameters.  Funnily, ‘top’ is indirectly
referred to here:

     Note that on multi-monitor displays (*note Multiple Terminals::),
     the window manager might position the frame differently than
     specified by the positional parameters in ALIST (*note Position
     Parameters::).  For example, some window managers have a policy of
     displaying the frame on the monitor that contains the largest part
     of the window (a.k.a. the "dominating" monitor).

> In addition, is the
> limitation when it comes to `width' and `height' correct ("You cannot
> specify either `width' or `height', you must specify neither or both.")? If
> seems to work just fine when I supply only a `height' property.

I don't even understand where and how we were able to apply such a
restriction in the first place.  Anyway, we should rewrite both
doc-string and documentation.  As someone who always works with a single
main frame I have no practice with this function though.  So I'm
probably not the ideal choice for that task.

martin