master 95d827f21e 1/2: Fix cross-filesystem directory trashing (Bug#58721)

[Eli Zaretskii]

branch: master
commit 95d827f21ef7bc3ed91335a6418e17fbb4ed5c63
Author: Mike Kupfer <mkupfer@alum.berkeley.edu>
Commit: Eli Zaretskii <eliz@gnu.org>

    Fix cross-filesystem directory trashing (Bug#58721)
    
    * lisp/files.el (move-file-to-trash): When trashing a directory with
    the same name as something that's already in the trash, copy it into
    the trash folder and then delete it, rather than using rename-file.
---
 lisp/files.el | 21 +++++++++++++++++++--
 1 file changed, 19 insertions(+), 2 deletions(-)

diff --git a/lisp/files.el b/lisp/files.el
index b947451369..127cf77240 100644
--- a/lisp/files.el
+++ b/lisp/files.el
@@ -8596,10 +8596,27 @@ Otherwise, trash FILENAME using the freedesktop.org 
conventions,
                    (setq files-base (substring (file-name-nondirectory info-fn)
                                                 0 (- (length ".trashinfo"))))
                    (write-region nil nil info-fn nil 'quiet info-fn)))
-                ;; Finally, try to move the file to the trashcan.
+                ;; Finally, try to move the item to the trashcan.  If
+                 ;; it's a file, just move it.  Things are more
+                 ;; complicated for directories.  If the target
+                 ;; directory already exists (due to uniquification)
+                 ;; and the trash directory is in a different
+                 ;; filesystem, rename-file will error out, even when
+                 ;; 'overwrite' is non-nil.  Rather than worry about
+                 ;; whether we're crossing filesystems, just check if
+                 ;; we've moving a directory and the target directory
+                 ;; already exists.  That handles both the
+                 ;; same-filesystem and cross-filesystem cases.
                 (let ((delete-by-moving-to-trash nil)
                       (new-fn (file-name-concat trash-files-dir files-base)))
-                  (rename-file fn new-fn overwrite)))))))))
+                   (if (or (not is-directory)
+                           (not (file-exists-p new-fn)))
+                       (rename-file fn new-fn overwrite)
+                     (copy-directory fn
+                                     (file-name-as-directory new-fn)
+                                     t nil t)
+                     (delete-directory fn t))))))))))
+
 
 
 (defsubst file-attribute-type (attributes)