bug#6762: 23.2; Eshell bug in detecting read-only file (patch included)

[John Wiegley <jwiegley@gmail.com>]

Looks like a great patch to me.

John

On Jul 30, 2010, at 6:13 AM, Leo wrote:

> I have diff-default-read-only set to t and this prevents eshell from
> writing to diff files i.e.
> 
>  ESHELL$ git diff x..y > file.diff
> 
> fails due to its use of buffer-read-only, which doesn't necessary
> reflects the read-only state of a file.
> 
> The following patch tries to fix this.
> 
> Leo
> 
> commit b1dc6a427e43470981d4700b0c98aa21ecb03052
> Author: sdl.web@gmail.com
> Date:   Sat May 1 17:50:21 2010 +0100
> 
>    Better detection of read-only file in eshell-get-target
> 
> 	Modified lisp/eshell/esh-io.el
> diff --git a/lisp/eshell/esh-io.el b/lisp/eshell/esh-io.el
> index 1bcfe2b..3aa785c 100644
> --- a/lisp/eshell/esh-io.el
> +++ b/lisp/eshell/esh-io.el
> @@ -343,8 +343,9 @@ it defaults to `insert'."
> 	(let* ((exists (get-file-buffer target))
> 	       (buf (find-file-noselect target t)))
> 	  (with-current-buffer buf
> -	    (if buffer-read-only
> +	    (if buffer-file-read-only
> 		(error "Cannot write to read-only file `%s'" target))
> +	    (setq buffer-read-only nil)
> 	    (set (make-local-variable 'eshell-output-file-buffer)
> 		 (if (eq exists buf) 0 t))
> 	    (cond ((eq mode 'overwrite)
>