Please write in English if possible, because the Emacs maintainers
usually do not have translators to read other languages for them.

Your bug report will be posted to the emacs-pretest-bug@gnu.org mailing
list.

Please describe exactly what actions triggered the bug
and the precise symptoms of the bug:

Actions to reproduce:
Start emacs with '-q'
define the following function:

(defun sacha/decrease-font-size ()
  "Decreases the font size by 10%"
  (interactive)
  (set-face-attribute 'default
                      nil
                      :height
                      (floor (* 0.9
                (face-attribute 'default :height)))))
Maximize the emacs window
execute sacha/decrease-font-size
Symptoms:
Font size is reduced, but usable parts of emacs are also reduced - large
amounts of inaccessible whitespace left at the right/bottom of the window.

If Emacs crashed, and you have the Emacs process in the gdb debugger,
please include the output from the following gdb commands:
    `bt full' and `xbacktrace'.
If you would like to further debug the crash, please read the file
/usr/share/emacs/23.0.60/etc/DEBUG for instructions.


In GNU Emacs 23.0.60.1 (i486-pc-linux-gnu, GTK+ Version 2.14.3)
 of 2008-10-13 on rothera, modified by Debian
 (emacs-snapshot package, version 1:20081013-1)
Windowing system distributor `The X.Org Foundation', version 11.0.10502000
configured using `configure  '--build' 'i486-linux-gnu' '--host'
'i486-linux-gnu' '--prefix=/usr' '--sharedstatedir=/var/lib'
'--libexecdir=/usr/lib' '--localstatedir=/var' '--infodir=/usr/share/info'
'--mandir=/usr/share/man' '--with-pop=yes'
'--enable-locallisppath=/etc/emacs-snapshot:/etc/emacs:/usr/local/share/emacs/23.0.60/site-lisp:/usr/local/share/emacs/site-lisp:/usr/share/emacs/23.0.60/site-lisp:/usr/share/emacs/site-lisp'
'--with-x=yes' '--with-x-toolkit=gtk' 'build_alias=i486-linux-gnu'
'host_alias=i486-linux-gnu' 'CFLAGS=-DDEBIAN -DSITELOAD_PURESIZE_EXTRA=5000
-g -O2' 'LDFLAGS=-g -Wl,--as-needed' 'CPPFLAGS=''

Important settings:
  value of $LC_ALL: nil
  value of $LC_COLLATE: nil
  value of $LC_CTYPE: nil
  value of $LC_MESSAGES: nil
  value of $LC_MONETARY: nil
  value of $LC_NUMERIC: nil
  value of $LC_TIME: nil
  value of $LANG: en_CA.UTF-8
  value of $XMODIFIERS: nil
  locale-coding-system: utf-8-unix
  default-enable-multibyte-characters: t

Major mode: Emacs-Lisp

Minor modes in effect:
  tooltip-mode: t
  tool-bar-mode: t
  mouse-wheel-mode: t
  menu-bar-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  blink-cursor-mode: t
  global-auto-composition-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  line-number-mode: t
  transient-mark-mode: t

Recent input:
<help-echo> <help-echo> <down-mouse-1> <mouse-1> C-x
C-f e m a c <tab> <tab> e m <backspace> <backspace>
/ e m <tab> <tab> <help-echo> m y f <tab> <return>
<down-mouse-1> <mouse-1> <down-mouse-1> <mouse-1> C-x
C-e M-x s a c h a SPC d e SPC SPC SPC SPC <return>
M-x b u g SPC SPC SPC SPC <backspace> <backspace> <backspace>
<backspace> <backspace> <backspace> <backspace> <backspace>
<backspace> <backspace> <backspace> <backspace> <backspace>
<backspace> <backspace> <backspace> <backspace> <backspace>
<backspace> <backspace> <backspace> r e p o SPC SPC
r SPC SPC SPC SPC <return>

Recent messages:
Loading /etc/emacs/site-start.d/50dictionaries-common.el (source)...done
Loading /etc/emacs/site-start.d/50mit-scheme.el (source)...done
Loading /etc/emacs/site-start.d/50psvn.el (source)...done
For information about GNU Emacs and the GNU system, type C-h C-a.
Making completion list... [2 times]
Loading vc-git...done
sacha/decrease-font-size
Making completion list... [2 times]
call-interactively: Text is read-only [7 times]
Making completion list... [2 times]