bug#18357: 24.3.93; Calendar not fully displayed

[Stephen Berman <stephen.berman@gmx.net>]

0. emacs -Q
   (sanity check) M-x calendar => The Calendar is fully displayed in the
   lower fitted window.
1. M-x customize-option RET calendar-week-start-day RET, set value to 1
   and save for current session.
   M-x customize-face RET mode-line RET, show all attributes, check
   `Overline' set its value to `On' and save for current session.
2. M-x calendar => Only the last four lines of the Calendar are
   displayed in the lower fitted window.

It looks as if point is centered in the Calendar window, but if I type
`C-l', it displays the last five lines, not just the last four.  Also,
the date could be relevant, since point is on today's date, which is on
the last line of the displayed Calendar; if this changes on September 1,
I'll report back.

I'm not sure but I think I first observed this problem in my build of
2014-08-20.  I don't remember seeing it in my previous build of
2014-07-22, but if I do the above recipe with the executable from the
that build, I do see the problematic display, which suggests it is due
to a change in a non-pre-loaded lisp file, though nothing in the
ChangeLog looks relevant, so perhaps my memory of when this began is
failing me.

The Calendar display problem also happens in my 2014-08-21 build from
the trunk, but only when configured --without-toolkit-scroll-bars; a
trunk build with (GTK+) scroll bars (including the new horizontal scroll
bar) does not show the problem.  However, I just rebuilt the current
emacs-24 --without-toolkit-scroll-bars and still see the problem there.

In GNU Emacs 24.3.93.4 (x86_64-suse-linux-gnu, GTK+ Version 3.10.4)
 of 2014-08-29 on rosalinde
Repository revision: 117464 rgm@gnu.org-20140828191824-o5hn2x503w527yhn
Windowing system distributor `The X.Org Foundation', version 11.0.11403901
System Description:	openSUSE 13.1 (Bottle) (x86_64)

Configured using:
 `configure --without-toolkit-scroll-bars CFLAGS=-g3'

Important settings:
  value of $LANG: en_US.UTF-8
  value of $XMODIFIERS: @im=ibus
  locale-coding-system: utf-8-unix