update_mode_lines incremented twice in kill-all-local-variables?

[Pavel Janík]

Hi,

in buffer.c, we have:

DEFUN ("kill-all-local-variables", Fkill_all_local_variables, 
Skill_all_local_variables,

[...]

  /* Redisplay mode lines; we are changing major mode.  */

  update_mode_lines++;

[...]

  /* Force mode-line redisplay.  Useful here because all major mode
     commands call this function.  */
  update_mode_lines++;

Is there any reason to increment update_mode_lines *twice* in this
function?
-- 
Pavel Janík

/* Supposedly happens on VMS. */
error ("File size is negative");"
                  -- A piece of code in GNU Emacs