dired-dwim-target-directory (was: find-file-read-args)

[Juri Linkov]

There are some other minibuffer prompts that suffer from the lack
of the directory names of other Dired windows in the default values.

Trying to compare files in Dired with a directory in another Dired
window on the same frame using `ediff-files', `dired-diff',
`dired-compare-directories' was troublesome until now.  The following
patch adds directories from other Dired windows to the default values.

Index: lisp/dired-aux.el
===================================================================
RCS file: /sources/emacs/emacs/lisp/dired-aux.el,v
retrieving revision 1.197
diff -c -r1.197 dired-aux.el
*** lisp/dired-aux.el   13 Nov 2009 22:19:50 -0000      1.197
--- lisp/dired-aux.el   17 Nov 2009 17:43:00 -0000
***************
*** 59,88 ****
  With prefix arg, prompt for second argument SWITCHES,
  which is options for `diff'."
    (interactive
!    (let ((current (dired-get-filename t))
!        (default (if (mark t)
!                     (save-excursion (goto-char (mark t))
!                                     (dired-get-filename t t)))))
!      (if (or (equal default current)
!            (and (not (equal (dired-dwim-target-directory)
!                             (dired-current-directory)))
!                 (not mark-active)))
!        (setq default nil))
       (require 'diff)
!      (list (read-file-name (format "Diff %s with%s: "
!                                  current
!                                  (if default
!                                      (concat " (default " default ")")
!                                    ""))
!                          (if default
!                              (dired-current-directory)
!                            (dired-dwim-target-directory))
!                          default t)
!          (if current-prefix-arg
!              (read-string "Options for diff: "
!                           (if (stringp diff-switches)
!                               diff-switches
!                             (mapconcat 'identity diff-switches " ")))))))
    (diff file (dired-get-filename t) switches))
  
  ;;;###autoload
--- 59,85 ----
  With prefix arg, prompt for second argument SWITCHES,
  which is options for `diff'."
    (interactive
!    (let* ((current (dired-get-filename t))
!         (target-dir (dired-dwim-target-directory))
!         (marked (and (mark t) (save-excursion
!                                 (goto-char (mark t))
!                                 (dired-get-filename nil t))))
!         (defaults
!           (append (dired-do-create-files-defaults nil target-dir)
!                   ;; Additional file with the mark.
!                   (and marked (list marked)))))
       (require 'diff)
!      (list
!       (minibuffer-with-setup-hook
!         (lambda ()
!           (set (make-local-variable 'minibuffer-default-add-function) nil)
!           (setq minibuffer-default defaults))
!       (read-file-name (format "Diff %s with: " current) target-dir nil t))
!       (if current-prefix-arg
!         (read-string "Options for diff: "
!                      (if (stringp diff-switches)
!                          diff-switches
!                        (mapconcat 'identity diff-switches " ")))))))
    (diff file (dired-get-filename t) switches))
  
  ;;;###autoload
***************
*** 128,138 ****
      (not (and (= (nth 2 fa1) (nth 2 fa2))   - mark files with different UID
                (= (nth 3 fa1) (nth 3 fa2))))   and GID."
    (interactive
!    (list (read-directory-name (format "Compare %s with: "
!                                     (dired-current-directory))
!                             (dired-dwim-target-directory)
!                             (dired-dwim-target-directory))
!          (read-from-minibuffer "Mark if (lisp expr or RET): " nil nil t nil 
"nil")))
    (let* ((dir1 (dired-current-directory))
           (file-alist1 (dired-files-attributes dir1))
           (file-alist2 (dired-files-attributes dir2))
--- 125,141 ----
      (not (and (= (nth 2 fa1) (nth 2 fa2))   - mark files with different UID
                (= (nth 3 fa1) (nth 3 fa2))))   and GID."
    (interactive
!    (list
!     (let* ((target-dir (dired-dwim-target-directory))
!          (defaults (dired-do-create-files-defaults nil target-dir)))
!       (minibuffer-with-setup-hook
!         (lambda ()
!           (set (make-local-variable 'minibuffer-default-add-function) nil)
!           (setq minibuffer-default defaults))
!       (read-directory-name (format "Compare %s with: "
!                                    (dired-current-directory))
!                            target-dir target-dir t)))
!     (read-from-minibuffer "Mark if (lisp expr or RET): " nil nil t nil 
"nil")))
    (let* ((dir1 (dired-current-directory))
           (file-alist1 (dired-files-attributes dir1))
           (file-alist2 (dired-files-attributes dir2))

Index: lisp/ediff-util.el
===================================================================
RCS file: /sources/emacs/emacs/lisp/ediff-util.el,v
retrieving revision 1.99
diff -c -r1.99 ediff-util.el
*** lisp/ediff-util.el  13 Nov 2009 22:19:50 -0000      1.99
--- lisp/ediff-util.el  17 Nov 2009 17:43:23 -0000
***************
*** 3113,3133 ****
    (if (string= default-file "")
        (setq default-file nil))
  
!   (let (f)
!     (setq f (expand-file-name
!            (read-file-name
!             (format "%s%s "
!                     prompt
!                     (cond (default-file
!                             (concat " (default " default-file "):"))
!                           (t (concat " (default " default-dir "):"))))
!             default-dir
!             (or default-file default-dir)
!             t  ; must match, no-confirm
!             (if default-file (file-name-directory default-file))
!             )
!            default-dir
!            ))
      ;; If user entered a directory name, expand the default file in that
      ;; directory.  This allows the user to enter a directory name for the
      ;; B-file and diff against the default-file in that directory instead
--- 3113,3134 ----
    (if (string= default-file "")
        (setq default-file nil))
  
!   (let ((defaults (dired-do-create-files-defaults
!                  nil (dired-dwim-target-directory)))
!       f)
!     (setq f (minibuffer-with-setup-hook
!               (lambda () (setq minibuffer-default defaults))
!             (read-file-name
!              (format "%s%s "
!                      prompt
!                      (cond (default-file
!                              (concat " (default " default-file "):"))
!                            (t (concat " (default " default-dir "):"))))
!              default-dir
!              (or default-file default-dir)
!              t                        ; must match, no-confirm
!              (if default-file (file-name-directory default-file)))))
!     (setq f (expand-file-name f default-dir))
      ;; If user entered a directory name, expand the default file in that
      ;; directory.  This allows the user to enter a directory name for the
      ;; B-file and diff against the default-file in that directory instead

-- 
Juri Linkov
http://www.jurta.org/emacs/