[PATCH] Replace inhibit-startup-buffer-menu

[Andrew Burgess <andrew.burgess@embecosm.com>]

When opening multiple file from the command line emacs uses
`list-buffers' to display a list of buffers.  This is fine, except
that I normally use an alternative package for displaying a buffer
list, it would be nice if I could use something other than
`list-buffers' for this initial buffer list.

The patch below makes inhibit-startup-buffer-menu obsolete, and
introduces startup-buffer-menu-function.  This new variable is by
default `list-buffers', and so the current behaviour is maintained.

Setting startup-buffer-menu-function to nil turns off the buffer list,
or it can be set to a function, the intention being that the function
should display the buffer list.

I'm could probably achieve the same result by using
inhibit-startup-buffer-menu and emacs-startup-hook, but this felt like
a neater, more obvious solution.

All feedback welcome,

thanks,
Andrew

lisp/ChangeLog:

2014-10-06  Andrew Burgess  <andrew.burgess@embecosm.com>

	* startup.el (inhibit-startup-buffer-menu): Make obsolete.
	(startup-buffer-menu-function): New user-option.
	(command-line-1): When startup-buffer-menu-function is a function
	call it to display the buffer list.

etc/NEWS:

  [ In the section "* Startup Changes in Emacs 24.4" ]

** The user option `inhibit-startup-buffer-menu' is now obsolete,
instead use the new `startup-buffer-menu-function'.

** New user option `startup-buffer-menu-function', setting this to nil
turns off the initial buffer menu, alternatively, set this to a
function that will display the buffer list.


=== modified file 'lisp/startup.el'
*** lisp/startup.el	2014-08-29 22:13:43 +0000
--- lisp/startup.el	2014-10-06 19:16:18 +0000
*************** startup message unless he personally act
*** 99,104 ****
--- 99,117 ----
    :type 'boolean
    :group 'initialization)
  
+ (defcustom startup-buffer-menu-function 'list-buffers
+   "Function to display buffer list when more than 2 files are loaded.
+ Setting this to nil will turn off the buffer list when 2 or more
+ files are loaded, otherwise set this to a function that will
+ display the buffer list."
+   :type '(choice
+           (const    :tag "No buffer list" nil)
+           (function :tag "List function"))
+   :group 'initialization)
+ 
+ (make-obsolete-variable 'inhibit-startup-buffer-menu
+                         'startup-buffer-menu-function "24.3")
+ 
  (defvar command-switch-alist nil
    "Alist of command-line switches.
  Elements look like (SWITCH-STRING . HANDLER-FUNCTION).
*************** A fancy display is used on graphic displ
*** 2433,2440 ****
  	(and (> file-count 2)
  	     (not noninteractive)
  	     (not inhibit-startup-buffer-menu)
  	     (or (get-buffer-window first-file-buffer)
! 		 (list-buffers)))
  
        ;; Display a startup screen, after some preparations.
  
--- 2446,2455 ----
  	(and (> file-count 2)
  	     (not noninteractive)
  	     (not inhibit-startup-buffer-menu)
+ 	     startup-buffer-menu-function
+ 	     (functionp startup-buffer-menu-function)
  	     (or (get-buffer-window first-file-buffer)
! 		 (funcall startup-buffer-menu-function)))
  
        ;; Display a startup screen, after some preparations.