bug#2407: 23.0.90; Emacs chokes on empty command line argument

[Geralt]

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:

When running emacs with an empty command line argument like this:

emacs ''

it won't start and display the following message:

Option `' is ambiguous

This makes it impossible to just call emacs "$*" inside a shell script
(without checking if "$*" is an empty string).

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/23.0.90/etc/DEBUG for instructions.


In GNU Emacs 23.0.90.1 (i686-pc-linux-gnu, GTK+ Version 2.14.7)
 of 2009-02-17 on sascha-xps
Windowing system distributor `The X.Org Foundation', version 11.0.10502000
configured using `configure  '--prefix=/usr'
'--host=i686-pc-linux-gnu' '--mandir=/usr/share/man'
'--infodir=/usr/share/info' '--datadir=/usr/share' '--sysconfdir=/etc'
'--localstatedir=/var/lib' '--program-suffix=-emacs-23'
'--infodir=/usr/share/info/emacs-23' '--with-sound' '--with-x'
'--with-toolkit-scroll-bars' '--with-gif' '--with-jpeg' '--with-png'
'--with-rsvg' '--with-tiff' '--with-xpm' '--with-freetype'
'--with-xft' '--without-libotf' '--without-m17n-flt'
'--with-x-toolkit=gtk' '--without-hesiod' '--without-kerberos'
'--without-kerberos5' '--with-gpm' '--with-dbus'
'--build=i686-pc-linux-gnu' 'build_alias=i686-pc-linux-gnu'
'host_alias=i686-pc-linux-gnu' 'CFLAGS=-O2 -march=prescott -pipe'
'LDFLAGS=-Wl,-O1''

Important settings:
  value of $LC_ALL: nil
  value of $LC_COLLATE: nil
  value of $LC_CTYPE: de_DE.utf8
  value of $LC_MESSAGES: nil
  value of $LC_MONETARY: nil
  value of $LC_NUMERIC: nil
  value of $LC_TIME: nil
  value of $LANG: en_US.utf8
  value of $XMODIFIERS: nil
  locale-coding-system: utf-8-unix
  default-enable-multibyte-characters: t

Major mode: Lisp Interaction

Minor modes in effect:
  eldoc-mode: t
  auto-complete-mode: t
  iswitchb-mode: t
  which-function-mode: t
  minibuffer-depth-indicate-mode: t
  recentf-mode: t
  icicle-mode: t
  show-paren-mode: t
  auto-dictionary-mode: t
  flyspell-mode: t
  tooltip-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: -1
  global-auto-composition-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  column-number-mode: t
  line-number-mode: t
  transient-mark-mode: t

Recent input:
<f1> <help-echo> <help-echo> <help-echo> <help-echo>
<help-echo> <help-echo> <menu-bar> <help-menu> <se
nd-emacs-bug-report>

Recent messages:
Loading /home/sascha/.emacs.d/site-lisp/auto-complete/auto-complete.el
(source)...done
Loading /home/sascha/.emacs.d/site-lisp/auto-complete/ac-dabbrev.el
(source)...done
Loading /home/sascha/.emacs.d/site-lisp/my-stuff/init.el (source)...done
Starting new Ispell process [default] ...
For information about GNU Emacs and the GNU system, type C-h C-a.
Menu-Bar mode enabled
Buffer dictionary was nil
Ispell process killed
Local Ispell dictionary set to en
Buffer dictionary is now en