bug#18720: 25.0.50; `set-frame-size' reduces height instead of increases it, when set to larger value

[Drew Adams]

emacs -Q

Resize the frame using the mouse, so that the menu bar extends (is
wrapped) to be 3 lines.

(frame-height) ; ==> call it N

(set-frame-height nil (1+ N))

The frame height is *reduced* by one, not increased by one.

If the menu bar is wrapped to only 2 lines then the bug does not occur.

It does not matter what value option `frame-resize-pixelwise' has.
(And it should not matter - frame resizing should work regardless of its
value, with the only difference being the granularity - not the
direction - of resizing).

In GNU Emacs 25.0.50.1 (i686-pc-mingw32)
 of 2014-10-06 on LEG570
Bzr revision: 118063 monnier@iro.umontreal.ca-20141006174756-y7ha091r491l1ijw
Windowing system distributor `Microsoft Corp.', version 6.1.7601
Configured using:
 `configure --enable-checking=yes,glyphs 'CFLAGS=-O0 -g3'
 CPPFLAGS=-DGLYPH_DEBUG=1'