Re: The *Warnings* buffer and undo

[Glenn Morris <rgm@gnu.org>]

David Kastrup wrote:

> I don't think it is a good idea to let-bind buffer-undo-list here:
> instead it should generally be set to t in the buffer.

Maybe the following is better then. It would seem odd to me if
display-warning permanently disabled undo in pre-existing buffers.


*** warnings.el	21 Jan 2007 02:44:23 -0000	1.11
--- warnings.el	28 Mar 2007 20:49:50 -0000
***************
*** 218,225 ****
  	      but raise suspicion of a possible problem.
  :debug     -- info for debugging only.
  
! BUFFER-NAME, if specified, is the name of the buffer for logging the
! warning.  By default, it is `*Warnings*'.
  
  See the `warnings' custom group for user customization features.
  
--- 218,226 ----
  	      but raise suspicion of a possible problem.
  :debug     -- info for debugging only.
  
! BUFFER-NAME, if specified, is the name of the buffer for logging
! the warning.  By default, it is `*Warnings*'.  If this function
! has to create the buffer, it disables undo in the buffer.
  
  See the `warnings' custom group for user customization features.
  
***************
*** 227,242 ****
  `warning-fill-prefix' for additional programming features."
    (unless level
      (setq level :warning))
    (if (assq level warning-level-aliases)
        (setq level (cdr (assq level warning-level-aliases))))
    (or (< (warning-numeric-level level)
           (warning-numeric-level warning-minimum-log-level))
        (warning-suppress-p type warning-suppress-log-types)
        (let* ((typename (if (consp type) (car type) type))
! 	     (buffer (get-buffer-create (or buffer-name "*Warnings*")))
  	     (level-info (assq level warning-levels))
  	     start end)
  	(with-current-buffer buffer
  	  (goto-char (point-max))
  	  (when (and warning-series (symbolp warning-series))
  	    (setq warning-series
--- 228,249 ----
  `warning-fill-prefix' for additional programming features."
    (unless level
      (setq level :warning))
+   (unless buffer-name
+     (setq buffer-name "*Warnings*"))
    (if (assq level warning-level-aliases)
        (setq level (cdr (assq level warning-level-aliases))))
    (or (< (warning-numeric-level level)
           (warning-numeric-level warning-minimum-log-level))
        (warning-suppress-p type warning-suppress-log-types)
        (let* ((typename (if (consp type) (car type) type))
!              (old (get-buffer buffer-name))
! 	     (buffer (get-buffer-create buffer-name))
  	     (level-info (assq level warning-levels))
  	     start end)
  	(with-current-buffer buffer
+           ;; If we created the buffer, disable undo.
+           (unless old
+             (setq buffer-undo-list t))
  	  (goto-char (point-max))
  	  (when (and warning-series (symbolp warning-series))
  	    (setq warning-series