Revert Tramp commit from 2017-11-20

* lisp/net/tramp.el (tramp-drop-volume-letter)
(tramp-handle-find-backup-file-name): Revert change from
2017-11-20.  Emacs' `make-backup-file-name-1' handles this
case now.

diff --git a/lisp/net/tramp.el b/lisp/net/tramp.el
index 6b0b1da6eb61e46a397403768abb085beb20bb17..124da173484e14ce31afc505b26bc4568c6d44d6 100644 (file)
--- a/lisp/net/tramp.el
+++ b/lisp/net/tramp.el
@@ -1858,8 +1858,7 @@ letter into the file name.  This function removes it."
      (if (tramp-compat-file-name-quoted-p name)
         'tramp-compat-file-name-quote 'identity)
      (let ((name (tramp-compat-file-name-unquote name)))
-       ;; A volume letter could occur also in encoded backup file names.
-       (if (string-match "\\(\\`[[:alpha:]]:/\\|/!drive_[[:alpha:]]\\)" name)
+       (if (string-match "\\`[a-zA-Z]:/" name)
           (replace-match "/" nil t name)
         name)))))
 
@@ -3226,23 +3225,21 @@ User is always nil."
 (defun tramp-handle-find-backup-file-name (filename)
   "Like `find-backup-file-name' for Tramp files."
   (with-parsed-tramp-file-name filename nil
-    (mapcar
-     'tramp-drop-volume-letter
-     (let ((backup-directory-alist
-           (if tramp-backup-directory-alist
-               (mapcar
-                (lambda (x)
-                  (cons
-                   (car x)
-                   (if (and (stringp (cdr x))
-                            (file-name-absolute-p (cdr x))
-                            (not (tramp-tramp-file-p (cdr x))))
-                       (tramp-make-tramp-file-name
-                        method user domain host port (cdr x) hop)
-                     (cdr x))))
-                tramp-backup-directory-alist)
-             backup-directory-alist)))
-       (tramp-run-real-handler 'find-backup-file-name (list filename))))))
+    (let ((backup-directory-alist
+          (if tramp-backup-directory-alist
+              (mapcar
+               (lambda (x)
+                 (cons
+                  (car x)
+                  (if (and (stringp (cdr x))
+                           (file-name-absolute-p (cdr x))
+                           (not (tramp-tramp-file-p (cdr x))))
+                      (tramp-make-tramp-file-name
+                       method user domain host port (cdr x) hop)
+                    (cdr x))))
+               tramp-backup-directory-alist)
+            backup-directory-alist)))
+      (tramp-run-real-handler 'find-backup-file-name (list filename)))))
 
 (defun tramp-handle-insert-directory
   (filename switches &optional wildcard full-directory-p)