Recent bug in insert-directory.

Recent bug in insert-directory.

[Luc Teirlinck]

If you do not have "-a" in `dired-listing-switches', an empty directory
gets listed in a Dired buffer as:

  /home/teirllm/empty:
  total used in directory 0 available 21863712
//DIRED-OPTIONS// --quoting-style=(null)

The last line looks weird.  This must be a very recent bug, or I would
have noticed it sooner.  The code in `insert-directory' apparently does
no longer take into account that for an empty directory we get:

[bash2.05b.0 ~ 3 2] ls -l --dired empty
  total 0
//DIRED-OPTIONS// --quoting-style=(null)

without any //DIRED// line.

Or is this just because my version of ls is too old?

The patch below fixes the bug.  However, I am not familiar with the
"error" stuff that led to the recent changes that introduced the bug.
I am not sure whether or not the "error problem" can occur for an
empty directory, listed without "-a".  If not, the patch below should
be sufficient.  Otherwise, additional (or other) changes would be needed.

===File ~/files.el-diff=====================================
*** files.el	04 Jan 2005 16:51:47 -0600	1.742
--- files.el	08 Jan 2005 22:22:27 -0600	
***************
*** 4550,4594 ****
  	  (when (if (stringp switches)
  		    (string-match "--dired\\>" switches)
  		  (member "--dired" switches))
  	    (forward-line -2)
              (when (looking-at "//SUBDIRED//")
                (delete-region (point) (progn (forward-line 1) (point)))
                (forward-line -1))
! 	    (when (looking-at "//DIRED//")
! 	      (let ((end (line-end-position))
! 		    (linebeg (point))
! 		    error-lines)
! 		;; Find all the lines that are error messages,
! 		;; and record the bounds of each one.
! 		(goto-char beg)
! 		(while (< (point) linebeg)
! 		  (or (eql (following-char) ?\s)
! 		      (push (list (point) (line-end-position)) error-lines))
! 		  (forward-line 1))
! 		(setq error-lines (nreverse error-lines))
! 		;; Now read the numeric positions of file names.
! 		(goto-char linebeg)
! 		(forward-word 1)
! 		(forward-char 3)
! 		(while (< (point) end)
! 		  (let ((start (insert-directory-adj-pos
  				(+ beg (read (current-buffer)))
! 				error-lines))
! 			(end (insert-directory-adj-pos
! 			      (+ beg (read (current-buffer)))
! 			      error-lines)))
! 		    (if (memq (char-after end) '(?\n ?\ ))
! 			;; End is followed by \n or by " -> ".
! 			(put-text-property start end 'dired-filename t)
! 		      ;; It seems that we can't trust ls's output as to
! 		      ;; byte positions of filenames.
! 		      (put-text-property beg (point) 'dired-filename nil)
! 		      (end-of-line))))
! 		(goto-char end)
! 		(beginning-of-line)
! 		(delete-region (point) (progn (forward-line 1) (point))))
! 	      (if (looking-at "//DIRED-OPTIONS//")
! 		  (delete-region (point) (progn (forward-line 1) (point))))))
  
  	  ;; Now decode what read if necessary.
  	  (let ((coding (or coding-system-for-read
--- 4550,4603 ----
  	  (when (if (stringp switches)
  		    (string-match "--dired\\>" switches)
  		  (member "--dired" switches))
+ 	    ;; The following overshoots by one line for an empty
+ 	    ;; directory listed with "--dired", but without "-a"
+ 	    ;; switch, where the ls output contains a
+ 	    ;; "//DIRED-OPTIONS//" line, but no "//DIRED//" line.
+ 	    ;; We take care of that case later.
  	    (forward-line -2)
              (when (looking-at "//SUBDIRED//")
                (delete-region (point) (progn (forward-line 1) (point)))
                (forward-line -1))
! 	    (if (looking-at "//DIRED//")
! 		(let ((end (line-end-position))
! 		      (linebeg (point))
! 		      error-lines)
! 		  ;; Find all the lines that are error messages,
! 		  ;; and record the bounds of each one.
! 		  (goto-char beg)
! 		  (while (< (point) linebeg)
! 		    (or (eql (following-char) ?\s)
! 			(push (list (point) (line-end-position)) error-lines))
! 		    (forward-line 1))
! 		  (setq error-lines (nreverse error-lines))
! 		  ;; Now read the numeric positions of file names.
! 		  (goto-char linebeg)
! 		  (forward-word 1)
! 		  (forward-char 3)
! 		  (while (< (point) end)
! 		    (let ((start (insert-directory-adj-pos
! 				  (+ beg (read (current-buffer)))
! 				  error-lines))
! 			  (end (insert-directory-adj-pos
  				(+ beg (read (current-buffer)))
! 				error-lines)))
! 		      (if (memq (char-after end) '(?\n ?\ ))
! 			  ;; End is followed by \n or by " -> ".
! 			  (put-text-property start end 'dired-filename t)
! 			;; It seems that we can't trust ls's output as to
! 			;; byte positions of filenames.
! 			(put-text-property beg (point) 'dired-filename nil)
! 			(end-of-line))))
! 		  (goto-char end)
! 		  (beginning-of-line)
! 		  (delete-region (point) (progn (forward-line 1) (point))))
! 	      ;; Take care of the case where the ls output contains a
! 	      ;; "//DIRED-OPTIONS//"-line, but no "//DIRED//"-line
! 	      ;; and we went one line too far back (see above.)
! 	      (forward-line 1))
! 	    (if (looking-at "//DIRED-OPTIONS//")
! 		(delete-region (point) (progn (forward-line 1) (point)))))
  
  	  ;; Now decode what read if necessary.
  	  (let ((coding (or coding-system-for-read
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