bug#19400: 24.4.50; `completion-separator-self-insert-command' calls `undefined' with error

[Nicolas Richard]

Hello,

From:
emacs -Q -f dynamic-completion-mode

Open a vc controlled directory with vc-dir

Hit ^

Instead of "^ is undefined", I get
"completion-separator-self-insert-command: Wrong number of arguments: (0
. 0), 1"

backtrace is :

Debugger entered--Lisp error: (wrong-number-of-arguments (0 . 0) 1)
  undefined(1)
  completion-separator-self-insert-command(1)
  call-interactively(completion-separator-self-insert-command nil nil)
  command-execute(completion-separator-self-insert-command)

Have the function "undefined" accept (and ignore) any argument would be
an easy workaround. WDYT ?

-- 
Nicolas Richard