bug#1114: M-` results in huge minibuffer

[Geoff Gole]

In certain conditions M-` will cause emacs to display a huge
minibuffer, occupying most of the frame. To replicate:

start an emacs -Q
C-x 3
M-`

This seems to mostly occur when the frame contains only vertical
splits (that's vertical as in C-x 3), but in some cases a window setup
containing a horizontal split also shows the bug.

Some example key sequences, each starting from a fresh emacs with
exactly one window:

M-` -> fine
C-x 3 M-` -> bug
C-x 3 C-x 3 M-` -> bug
C-x 3 C-x 2 M-` -> fine
C-x 3 C-x 3 C-x o C-x o C-x 2 M-` -> bug
C-x 3 C-x 3 C-x 2 M-` -> fine

I hope that's clear.

GNU Emacs 22.2.1 (i386-mingw-nt5.1.2600) of 2008-03-26 on RELEASE
Also observed in GNU Emacs 22.1.50.1 (i386-mingw-nt5.1.2600) of
2007-08-18 on TPAD

Windowing system distributor `Microsoft Corp.', version 5.1.2600
configured using `configure --with-gcc (3.4)'