bug#23854: 25.0.95; vertical completions-format layout clobbered

[Michael Heerdegen <michael_heerdegen@web.de>]

Hello,

when using completions-format -> vertical, and candidates are of quite
different lengths, the *Completions* display is often clobbered.

There are candidates put into a second columns although there is not
enough horizontal space.

And the last candidates are sometimes aligned to the nth column,
while the first column is empty.

Example for two columns:


|a   a candidat|   ;; doesn't fit in column
|xy  foo       |
|gnu image     |
|    bar       |   ;; strange
|    emacs     |



Thanks,

Michael.



In GNU Emacs 25.0.95.1 (x86_64-pc-linux-gnu, GTK+ Version 3.20.6)
 of 2016-06-21 built on drachen
Repository revision: 6cdd8f7153b553c6dc02be47e04a2e75117b6fe4
Windowing system distributor 'The X.Org Foundation', version 11.0.11803000
System Description:	Debian GNU/Linux testing (stretch)

Configured features:
XPM JPEG TIFF GIF PNG RSVG IMAGEMAGICK SOUND DBUS GSETTINGS NOTIFY
LIBXML2 FREETYPE XFT ZLIB TOOLKIT_SCROLL_BARS GTK3 X11

Important settings:
  value of $LC_ALL: de_DE.utf8
  value of $LC_COLLATE: C
  value of $LC_TIME: C
  value of $LANG: de_DE.utf8
  locale-coding-system: utf-8-unix

Major mode: Emacs-Lisp