(dired-do-create-files): On DOS/Windows, allow to

rename a directory to a name that differs only by its letter case.

1 files changed, 19 insertions, 1 deletions

diff --git a/lisp/dired-aux.el b/lisp/dired-aux.el
index 8ff4128350d..4a2d8932457 100644
--- a/lisp/dired-aux.el
+++ b/lisp/dired-aux.el
@@ -1232,7 +1232,25 @@ ESC or `q' to not overwrite any of the remaining files,
                     (concat (if dired-one-file op1 operation) " %s to: ")
                     (dired-dwim-target-directory)
                     op-symbol arg rfn-list)))
-         (into-dir (cond ((null how-to) (file-directory-p target))
+         (into-dir (cond ((null how-to)
+                          ;; Allow DOS/Windows users to change the letter
+                          ;; case of a directory.  If we don't test these
+                          ;; conditions up front, file-directory-p below
+                          ;; will return t because the filesystem is
+                          ;; case-insensitive, and Emacs will try to move
+                          ;; foo -> foo/foo, which fails.
+                          (if (and (memq system-type '(ms-dos windows-nt))
+                                   (eq op-symbol 'move)
+                                   dired-one-file
+                                   (string= (downcase
+                                             (expand-file-name (car fn-list)))
+                                            (downcase
+                                             (expand-file-name target)))
+                                   (not (string=
+                                         (file-name-nondirectory (car fn-list))
+                                         (file-name-nondirectory target))))
+                              nil
+                            (file-directory-p target)))
                          ((eq how-to t) nil)
                          (t (funcall how-to target)))))
     (if (and (consp into-dir) (functionp (car into-dir)))