Re: insert-file-contents and format-decode

[martin rudalics]

>     !   (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)))))
>
> That pateh is basically good, but it could be simpler.  Instead of
> letting insert-file-contents produce an undo entry and taking it off
> and taking it apart, it would be better to inhibit undo around
> insert-file-contents and generate the undo entry from scratch in all
> cases.  When no format decoding is done, VALUE has the size you need.

It's complicated because I may have to create the (t HIGH . LOW) entry
to indicate that the buffer previously had "unmodified" status.  With my
solution I let `insert-file-contents' take care of that automatically.
With your solution I would have to create it manually and care about the
modification time myself.  Is it worth the trouble?