Re: insert-file-contents and format-decode

[martin rudalics]

>     Finally, I'm completely uncertain what to do about `format-insert-file':
>     That function explicitly prompts for a format and does `format-decode'
>     after inserting the file and running any `after-insert-file-functions'.
>     Shall we treat this is as a sequence of
>
>
>     (insert-file-contents filename nil beg end)
>
>     (let ((format-alist nil))
>        (format-decode-region (point) (+ (point) size) format))
>
>     with _two_ `buffer-undo-list' entries and `after-change-functions'
>     calls?
>
> No, I suggest making just one undo entry for the insertion
> of the decoded text.  Just as `insert-file-contents' would do.

I tried this in the attached patch.

*** format.el   Tue Jan 23 06:40:02 2007
--- format.el   Mon Jul  2 08:54:40 2007
***************
*** 429,441 ****
          (fmt (format-read (format "Read file `%s' in format: "
                                    (file-name-nondirectory file)))))
       (list file fmt)))
!   (let (value size)
!     (let ((format-alist nil))
!       (setq value (insert-file-contents filename nil beg end))
!       (setq size (nth 1 value)))
!     (if format
!       (setq size (format-decode format size)
!             value (list (car value) size)))
      value))
  
  (defun format-read (&optional prompt)
--- 429,462 ----
          (fmt (format-read (format "Read file `%s' in format: "
                                    (file-name-nondirectory file)))))
       (list file fmt)))
!   (let (value size old-undo)
!     ;; Record only one undo entry for the insertion.  Inhibit point-motion and
!     ;; modification hooks as with `insert-file-contents'.
!     (let ((inhibit-point-motion-hooks t)
!         (inhibit-modification-hooks t))
!       ;; Don't bind `buffer-undo-list' to t here to assert that
!       ;; `insert-file-contents' may record whether the buffer was unmodified
!       ;; before.
!       (let ((format-alist nil))
!       (setq value (insert-file-contents filename nil beg end))
!       (setq size (nth 1 value)))
!       (when (consp buffer-undo-list)
!       (let ((head (car buffer-undo-list)))
!         (when (and (consp head)
!                    (equal (car head) (point))
!                    (equal (cdr head) (+ (point) size)))
!           ;; Remove first entry from `buffer-undo-list', we shall insert
!           ;; another one below.
!           (setq old-undo (cdr buffer-undo-list)))))
!       (when format
!       (let ((buffer-undo-list t))
!         (setq size (format-decode format size)
!               value (list (car value) size)))
!       (unless (eq buffer-undo-list t)
!         (setq buffer-undo-list
!               (cons (cons (point) (+ (point) size)) old-undo)))))
!     (unless inhibit-modification-hooks
!       (run-hook-with-args 'after-change-functions (point) (+ (point) size) 0))
      value))
  
  (defun format-read (&optional prompt)