Sync with Tramp 2.0.52.

6 files changed, 286 insertions, 71 deletions

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index 8a831ee01d8..893c8ba68ef 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,3 +1,45 @@
+2006-01-22  Michael Albinus  <michael.albinus@gmx.de>
+
+        Sync with Tramp 2.0.52.
+
+        * net/tramp.el, net/tramp-ftp.el, net/tramp-util.el,
+        net/tramp-vc.el: Add code for unloading Tramp.  See comment before
+        `tramp-unload-tramp' for checklist.
+
+        * net/tramp.el: Require `timer-funcs' instead of `timer' if in
+        XEmacs.  Contributed by Steve Youngs <steve@sxemacs.org>.
+        (tramp-unload-file-name-handler-alist)
+        (tramp-unload-tramp): New defuns.
+        (tramp-advice-PC-expand-many-files): New defadvice.
+        (tramp-save-PC-expand-many-files, tramp-setup-complete) Defuns
+        removed.
+        (tramp-handle-expand-file-name): Remove double slash.
+        (tramp-handle-file-attributes-with-ls): Return t as 9th attribute.
+        It doesn't matter, because it will be converted later on.
+        (tramp-handle-file-ownership-preserved-p): Rewritten.  The old
+        implementation was just heuristic.
+        (tramp-post-connection): Set uid and gid properties.
+        (tramp-convert-file-attributes): Set file's gid change bit.
+        (tramp-get-remote-uid, tramp-get-remote-gid): New defuns.
+        (tramp-handle-expand-file-name): Use "~root" for tilde expansion
+        in case of su(do)? methods.  The home directory of the local user
+        will be taken else.
+        (tramp-open-connection-telnet)
+        (tramp-open-connection-rsh, tramp-open-connection-su)
+        (tramp-open-connection-multi): Set PS1 to "$ ".  Otherwise, a
+        local shell prompt could hurt.  Reported by Romain Francoise
+        <romain@orebokech.com>.
+        (tramp-let-maybe): Add `edebug-form-spec' property.
+        (tramp-handle-expand-file-name): Bind `default-directory' locally
+        to "/" in order to avoid problems with UNC shares or Cygwin
+        mounts.
+        (tramp-md5-function): Fix typo in error message.
+
+        * net/tramp-ftp.el (tramp-ftp-enable-ange-ftp): New defun.
+
+        * net/tramp-util.el (top): Apply `ignore' instead of `identity'
+        for byte-compiler pacification.
+
 2006-01-22  Andre Spiegel  <spiegel@gnu.org>
 
         * vc-rcs.el (vc-rcs-state-heuristic): Use file-attributes with
diff --git a/lisp/net/tramp-ftp.el b/lisp/net/tramp-ftp.el
index 53cc392ad7a..dc3742c231a 100644
--- a/lisp/net/tramp-ftp.el
+++ b/lisp/net/tramp-ftp.el
@@ -1,6 +1,6 @@
 ;;; tramp-ftp.el --- Tramp convenience functions for Ange-FTP -*- coding: iso-8859-1; -*-
 
-;; Copyright (C) 2002, 2003, 2004, 2005 Free Software Foundation, Inc.
+;; Copyright (C) 2002, 2003, 2004, 2005, 2006 Free Software Foundation, Inc.
 
 ;; Author: Michael Albinus <michael.albinus@gmx.de>
 ;; Keywords: comm, processes
@@ -63,8 +63,40 @@ present for backward compatibility."
         (a2 (rassq 'ange-ftp-completion-hook-function file-name-handler-alist)))
     (setq file-name-handler-alist
           (delete a1 (delete a2 file-name-handler-alist)))))
-(tramp-disable-ange-ftp)
-(eval-after-load "ange-ftp" '(tramp-disable-ange-ftp))
+
+(eval-after-load "ange-ftp"
+  '(when (functionp 'tramp-disable-ange-ftp)
+     (tramp-disable-ange-ftp)))
+
+;;;###autoload
+(defun tramp-ftp-enable-ange-ftp ()
+  ;; The following code is commented out in Ange-FTP.
+
+  ;;; This regexp takes care of real ange-ftp file names (with a slash
+  ;;; and colon).
+  ;;; Don't allow the host name to end in a period--some systems use /.:
+  (or (assoc "^/[^/:]*[^/:.]:" file-name-handler-alist)
+      (setq file-name-handler-alist
+            (cons '("^/[^/:]*[^/:.]:" . ange-ftp-hook-function)
+                  file-name-handler-alist)))
+
+  ;;; This regexp recognizes absolute filenames with only one component,
+  ;;; for the sake of hostname completion.
+  (or (assoc "^/[^/:]*\\'" file-name-handler-alist)
+      (setq file-name-handler-alist
+            (cons '("^/[^/:]*\\'" . ange-ftp-completion-hook-function)
+                  file-name-handler-alist)))
+
+  ;;; This regexp recognizes absolute filenames with only one component
+  ;;; on Windows, for the sake of hostname completion.
+  (and (memq system-type '(ms-dos windows-nt))
+       (or (assoc "^[a-zA-Z]:/[^/:]*\\'" file-name-handler-alist)
+           (setq file-name-handler-alist
+                 (cons '("^[a-zA-Z]:/[^/:]*\\'" .
+                         ange-ftp-completion-hook-function)
+                       file-name-handler-alist)))))
+
+(add-hook 'tramp-ftp-unload-hook 'tramp-ftp-enable-ange-ftp)
 
 ;; Define FTP method ...
 (defcustom tramp-ftp-method "ftp"
diff --git a/lisp/net/tramp-util.el b/lisp/net/tramp-util.el
index acb10727d46..666471d6429 100644
--- a/lisp/net/tramp-util.el
+++ b/lisp/net/tramp-util.el
@@ -1,7 +1,8 @@
 ;;; -*- coding: iso-2022-7bit; -*-
 ;;; tramp-util.el --- Misc utility functions to use with Tramp
 
-;; Copyright (C) 2001, 2002, 2003, 2004, 2005 Free Software Foundation, Inc.
+;; Copyright (C) 2001, 2002, 2003, 2004, 2005,
+;;   2006 Free Software Foundation, Inc.
 
 ;; Author: kai.grossjohann@gmx.net
 ;; Keywords: comm, extensions, processes
@@ -31,6 +32,10 @@
 (eval-when-compile (require 'cl))
 (require 'compile)
 (require 'tramp)
+(add-hook 'tramp-util-unload-hook
+          '(lambda ()
+             (when (featurep 'tramp)
+               (unload-feature 'tramp 'force))))
 
 ;; Define a Tramp minor mode. It's intention is to redefine some keys for Tramp
 ;; specific functions, like compilation.
@@ -42,7 +47,7 @@
       (defalias 'define-minor-mode 'identity)
       (defvar tramp-minor-mode))
   (unless (featurep 'xemacs)
-      (defalias 'add-menu-button 'identity)))
+    (defalias 'add-menu-button 'ignore)))
 
 (defvar tramp-minor-mode-map (make-sparse-keymap)
   "Keymap for Tramp minor mode.")
@@ -57,7 +62,14 @@
         (and tramp-minor-mode (tramp-tramp-file-p default-directory))))
 
 (add-hook 'find-file-hooks 'tramp-minor-mode t)
+(add-hook 'tramp-util-unload-hook
+          '(lambda ()
+             (remove-hook 'find-file-hooks 'tramp-minor-mode)))
+
 (add-hook 'dired-mode-hook 'tramp-minor-mode t)
+(add-hook 'tramp-util-unload-hook
+          '(lambda ()
+             (remove-hook 'dired-mode-hook 'tramp-minor-mode)))
 
 (defun tramp-remap-command (old-command new-command)
   "Replaces bindings of OLD-COMMAND by NEW-COMMAND.
diff --git a/lisp/net/tramp-vc.el b/lisp/net/tramp-vc.el
index c1806a4be24..368d85c8e57 100644
--- a/lisp/net/tramp-vc.el
+++ b/lisp/net/tramp-vc.el
@@ -1,7 +1,7 @@
 ;;; tramp-vc.el --- Version control integration for TRAMP.el
 
 ;; Copyright (C) 2000, 2001, 2002, 2003, 2004,
-;;   2005 Free Software Foundation, Inc.
+;;   2005, 2006 Free Software Foundation, Inc.
 
 ;; Author: Daniel Pittman <daniel@danann.net>
 ;; Keywords: comm, processes
@@ -220,34 +220,37 @@ Since TRAMP doesn't do async commands yet, this function doesn't, either."
 ;; Daniel Pittman <daniel@danann.net>
 ;;-(if (fboundp 'vc-call-backend)
 ;;-    () ;; This is the new VC for which we don't have an appropriate advice yet
+;;-)
 (unless (fboundp 'process-file)
-(if (fboundp 'vc-call-backend)
+  (if (fboundp 'vc-call-backend)
+      (defadvice vc-do-command
+        (around tramp-advice-vc-do-command
+                (buffer okstatus command file &rest flags)
+                activate)
+        "Invoke tramp-vc-do-command for tramp files."
+        (let ((file (symbol-value 'file)))    ;pacify byte-compiler
+          (if (or (and (stringp file)     (tramp-tramp-file-p file))
+                  (and (buffer-file-name) (tramp-tramp-file-p (buffer-file-name))))
+              (setq ad-return-value
+                    (apply 'tramp-vc-do-command-new buffer okstatus command
+                           file ;(or file (buffer-file-name))
+                           flags))
+            ad-do-it)))
     (defadvice vc-do-command
       (around tramp-advice-vc-do-command
-              (buffer okstatus command file &rest flags)
-              activate)
+              (buffer okstatus command file last &rest flags)
+              activate)
       "Invoke tramp-vc-do-command for tramp files."
-      (let ((file (symbol-value 'file)))    ;pacify byte-compiler
-        (if (or (and (stringp file)     (tramp-tramp-file-p file))
-                (and (buffer-file-name) (tramp-tramp-file-p (buffer-file-name))))
-            (setq ad-return-value
-                  (apply 'tramp-vc-do-command-new buffer okstatus command
-                         file ;(or file (buffer-file-name))
-                         flags))
-          ad-do-it)))
-  (defadvice vc-do-command
-    (around tramp-advice-vc-do-command
-            (buffer okstatus command file last &rest flags)
-            activate)
-    "Invoke tramp-vc-do-command for tramp files."
-    (let ((file (symbol-value 'file)))  ;pacify byte-compiler
-      (if (or (and (stringp file)     (tramp-tramp-file-p file))
-              (and (buffer-file-name) (tramp-tramp-file-p (buffer-file-name))))
-          (setq ad-return-value
-                (apply 'tramp-vc-do-command buffer okstatus command
-                       (or file (buffer-file-name)) last flags))
-        ad-do-it)))))
-;;-)
+      (let ((file (symbol-value 'file)))  ;pacify byte-compiler
+        (if (or (and (stringp file)     (tramp-tramp-file-p file))
+                (and (buffer-file-name) (tramp-tramp-file-p (buffer-file-name))))
+            (setq ad-return-value
+                  (apply 'tramp-vc-do-command buffer okstatus command
+                         (or file (buffer-file-name)) last flags))
+          ad-do-it))))
+
+  (add-hook 'tramp-unload-hook
+            '(lambda () (ad-unadvise 'vc-do-command))))
 
 
 ;; XEmacs uses this to do some of its work. Like vc-do-command, we
@@ -324,6 +327,9 @@ Since TRAMP doesn't do async commands yet, this function doesn't, either."
                      (or file (buffer-file-name)) args))
       ad-do-it)))
 
+(add-hook 'tramp-unload-hook
+          '(lambda () (ad-unadvise 'vc-simple-command)))
+
 
 ;; `vc-workfile-unchanged-p'
 ;; This function does not deal well with remote files, so we do the
@@ -364,6 +370,9 @@ Since TRAMP doesn't do async commands yet, this function doesn't, either."
             (tramp-vc-workfile-unchanged-p filename want-differences-if-changed))
     ad-do-it))
 
+(add-hook 'tramp-unload-hook
+          '(lambda () (ad-unadvise 'vc-workfile-unchanged-p)))
+
 
 ;; Redefine a function from vc.el -- allow tramp files.
 ;; `save-match-data' seems not to be required -- it isn't in
@@ -445,6 +454,9 @@ filename we are thinking about..."
                      (tramp-handle-vc-user-login-name uid)))) ; get the owner name
         ad-do-it)))                     ; else call the original
 
+(add-hook 'tramp-unload-hook
+          '(lambda () (ad-unadvise 'vc-user-login-name)))
+
 
 ;; Determine the name of the user owning a file.
 (defun tramp-file-owner (filename)
@@ -486,6 +498,9 @@ filename we are thinking about..."
                      (tramp-file-owner filename)))) ; get the owner name
         ad-do-it)))                     ; else call the original
 
+(add-hook 'tramp-unload-hook
+          '(lambda () (ad-unadvise 'vc-file-owner)))
+
 
 ;; We need to make the version control software backend version
 ;; information local to the current buffer. This is because each TRAMP
@@ -506,7 +521,11 @@ This makes remote VC work correctly at the cost of some processing time."
              (tramp-tramp-file-p (buffer-file-name)))
     (make-local-variable 'vc-rcs-release)
     (setq vc-rcs-release nil)))
+
 (add-hook 'find-file-hooks 'tramp-vc-setup-for-remote t)
+(add-hook 'tramp-unload-hook
+          '(lambda ()
+             (remove-hook 'find-file-hooks 'tramp-vc-setup-for-remote)))
 
 ;; No need to load this again if anyone asks.
 (provide 'tramp-vc)
diff --git a/lisp/net/tramp.el b/lisp/net/tramp.el
index 8555c9a83c5..10a5dd9eedf 100644
--- a/lisp/net/tramp.el
+++ b/lisp/net/tramp.el
@@ -2,7 +2,7 @@
 ;;; tramp.el --- Transparent Remote Access, Multiple Protocol
 
 ;; Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003, 2004,
-;;   2005 Free Software Foundation, Inc.
+;;   2005, 2006 Free Software Foundation, Inc.
 
 ;; Author: Kai Gro,A_(Bjohann <kai.grossjohann@gmx.net>
 ;;         Michael Albinus <michael.albinus@gmx.de>
@@ -67,8 +67,15 @@
 
 ;; The Tramp version number and bug report address, as prepared by configure.
 (require 'trampver)
+(add-hook 'tramp-unload-hook
+          '(lambda ()
+             (when (featurep 'trampver)
+               (unload-feature 'trampver 'force))))
+
+(if (featurep 'xemacs)
+    (require 'timer-funcs)
+  (require 'timer))
 
-(require 'timer)
 (require 'format-spec)                  ;from Gnus 5.8, also in tar ball
 ;; As long as password.el is not part of (X)Emacs, it shouldn't
 ;; be mandatory
@@ -87,6 +94,10 @@
 
 (autoload 'tramp-uuencode-region "tramp-uu"
   "Implementation of `uuencode' in Lisp.")
+(add-hook 'tramp-unload-hook
+          '(lambda ()
+             (when (featurep 'tramp-uu)
+               (unload-feature 'tramp-uu 'force))))
 
 (unless (fboundp 'uudecode-decode-region)
   (autoload 'uudecode-decode-region "uudecode"))
@@ -110,10 +121,20 @@ Nil means to use a separate filename syntax for Tramp.")
 ;; tramp-ftp supports Ange-FTP only.  Not suited for XEmacs therefore.
 (unless (featurep 'xemacs)
   (eval-after-load "tramp"
-    '(require 'tramp-ftp)))
+    '(progn
+       (require 'tramp-ftp)
+       (add-hook 'tramp-unload-hook
+                 '(lambda ()
+                    (when (featurep 'tramp-ftp)
+                      (unload-feature 'tramp-ftp 'force)))))))
 (when (and tramp-unified-filenames (featurep 'xemacs))
   (eval-after-load "tramp"
-    '(require 'tramp-efs)))
+    '(progn
+       (require 'tramp-efs)
+       (add-hook 'tramp-unload-hook
+                 '(lambda ()
+                    (when (featurep 'tramp-efs)
+                      (unload-feature 'tramp-efs 'force)))))))
 
 ;; tramp-smb uses "smbclient" from Samba.
 ;; Not available under Cygwin and Windows, because they don't offer
@@ -121,7 +142,12 @@ Nil means to use a separate filename syntax for Tramp.")
 ;; UNC file names like "//host/share/localname".
 (unless (memq system-type '(cygwin windows-nt))
   (eval-after-load "tramp"
-    '(require 'tramp-smb)))
+    '(progn
+       (require 'tramp-smb)
+       (add-hook 'tramp-unload-hook
+                 '(lambda ()
+                    (when (featurep 'tramp-smb)
+                      (unload-feature 'tramp-smb 'force)))))))
 
 (eval-when-compile
   (require 'cl)
@@ -1445,7 +1471,7 @@ the visited file modtime.")
         ((fboundp 'md5-encode)
          (lambda (x) (base64-encode-string
                       (funcall (symbol-function 'md5-encode) x))))
-        (t (error "Coulnd't find an `md5' function")))
+        (t (error "Couldn't find an `md5' function")))
   "Function to call for running the MD5 algorithm.")
 
 (defvar tramp-end-of-output
@@ -2012,6 +2038,7 @@ The intent is to protect against `obsolete variable' warnings."
      (let ((,variable ,value))
        ,@body)))
 (put 'tramp-let-maybe 'lisp-indent-function 2)
+(put 'tramp-let-maybe 'edebug-form-spec t)
 
 ;;; Config Manipulation Functions:
 
@@ -2370,8 +2397,8 @@ target of the symlink differ."
      ;; 8. File modes, as a string of ten letters or dashes as in ls -l.
      res-filemodes
      ;; 9. t iff file's gid would change if file were deleted and
-     ;; recreated.
-     nil                                ;hm?
+     ;; recreated.  Will be set in `tramp-convert-file-attributes'
+     t
      ;; 10. inode number.
      res-inode
      ;; 11. Device number.  Will be replaced by a virtual device number.
@@ -2627,9 +2654,12 @@ of."
 (defun tramp-handle-file-ownership-preserved-p (filename)
   "Like `file-ownership-preserved-p' for tramp files."
   (with-parsed-tramp-file-name filename nil
-    (or (not (file-exists-p filename))
-        ;; Existing files must be writable.
-        (zerop (tramp-run-test "-O" filename)))))
+    (let ((attributes (file-attributes filename)))
+      ;; Return t if the file doesn't exist, since it's true that no
+      ;; information would be lost by an (attempted) delete and create.
+      (or (null attributes)
+          (= (nth 2 attributes)
+             (tramp-get-remote-uid multi-method method user host))))))
 
 ;; Other file name ops.
 
@@ -3487,6 +3517,17 @@ the result will be a local, non-Tramp, filename."
         (when (string-match "\\`\\(~[^/]*\\)\\(.*\\)\\'" localname)
           (let ((uname (match-string 1 localname))
                 (fname (match-string 2 localname)))
+            ;; We cannot simply apply "~/", because under sudo "~/" is
+            ;; expanded to the local user home directory but to the
+            ;; root home directory.  On the other hand, using always
+            ;; the default user name for tilde expansion is not
+            ;; appropriate either, because ssh and companions might
+            ;; use a user name from the config file.
+            (when (and (string-equal uname "~")
+                       (string-match
+                        "\\`su\\(do\\)?\\'"
+                        (tramp-find-method multi-method method user host)))
+              (setq uname (concat uname (or user "root"))))
             ;; CCC fanatic error checking?
             (set-buffer (tramp-get-buffer multi-method method user host))
             (erase-buffer)
@@ -3499,17 +3540,24 @@ the result will be a local, non-Tramp, filename."
             (setq uname (buffer-substring (point) (tramp-line-end-position)))
             (setq localname (concat uname fname))
             (erase-buffer)))
+        ;; There might be a double slash, for example when "~/"
+        ;; expands to "/". Remove this.
+        (while (string-match "//" localname)
+          (setq localname (replace-match "/" t t localname)))
         ;; No tilde characters in file name, do normal
         ;; expand-file-name (this does "/./" and "/../").  We bind
-        ;; directory-sep-char here for XEmacs on Windows, which
-        ;; would otherwise use backslash.
+        ;; directory-sep-char here for XEmacs on Windows, which would
+        ;; otherwise use backslash.  `default-directory' is bound to
+        ;; "/", because on Windows there would be problems with UNC
+        ;; shares or Cygwin mounts.
         (tramp-let-maybe directory-sep-char ?/
-          (tramp-make-tramp-file-name
-           multi-method (or method (tramp-find-default-method user host))
-           user host
-           (tramp-drop-volume-letter
-            (tramp-run-real-handler 'expand-file-name
-                                    (list localname)))))))))
+          (let ((default-directory "/"))
+            (tramp-make-tramp-file-name
+             multi-method (or method (tramp-find-default-method user host))
+             user host
+             (tramp-drop-volume-letter
+              (tramp-run-real-handler 'expand-file-name
+                                      (list localname))))))))))
 
 ;; old version follows.  it uses ".." to cross file handler
 ;; boundaries.
@@ -4294,6 +4342,17 @@ Falls back to normal file name handler if no tramp file name handler exists."
              (cons tramp-completion-file-name-regexp
                    'tramp-completion-file-name-handler))
 
+;;;###autoload
+(defun tramp-unload-file-name-handler-alist ()
+  (setq file-name-handler-alist
+        (delete (rassoc 'tramp-file-name-handler
+                        file-name-handler-alist)
+                (delete (rassoc 'tramp-completion-file-name-handler
+                                file-name-handler-alist)
+                        file-name-handler-alist))))
+
+(add-hook 'tramp-unload-hook 'tramp-unload-file-name-handler-alist)
+
 (defun tramp-repair-jka-compr ()
   "If jka-compr is already loaded, move it to the front of
 `file-name-handler-alist'.  On Emacs 22 or so this will not be
@@ -4353,22 +4412,16 @@ necessary anymore."
                  (read (current-buffer))))))
         (list (expand-file-name name))))))
 
-;; Check for complete.el and override PC-expand-many-files if appropriate.
-(eval-and-compile
-  (defun tramp-save-PC-expand-many-files (name))); avoid compiler warning
-
-(defun tramp-setup-complete ()
-  (fset 'tramp-save-PC-expand-many-files
-        (symbol-function 'PC-expand-many-files))
-  (defun PC-expand-many-files (name)
-    (if (tramp-tramp-file-p name)
-        (funcall (symbol-function 'expand-many-files) name)
-      (tramp-save-PC-expand-many-files name))))
-
-;; Why isn't eval-after-load sufficient?
-(if (fboundp 'PC-expand-many-files)
-    (tramp-setup-complete)
-  (eval-after-load "complete" '(tramp-setup-complete)))
+(eval-after-load "complete"
+  '(progn
+     (defadvice PC-expand-many-files
+       (around tramp-advice-PC-expand-many-files (name) activate)
+       "Invoke `tramp-handle-expand-many-files' for tramp files."
+       (if (tramp-tramp-file-p name)
+           (setq ad-return-value (tramp-handle-expand-many-files name))
+         ad-do-it))
+     (add-hook 'tramp-unload-hook
+               '(lambda () (ad-unadvise 'PC-expand-many-files)))))
 
 ;;; File name handler functions for completion mode
 
@@ -4940,6 +4993,9 @@ Function may have 0-3 parameters."
              auto-save-default)
     (auto-save-mode 1)))
 (add-hook 'find-file-hooks 'tramp-set-auto-save t)
+(add-hook 'tramp-unload-hook
+          '(lambda ()
+             (remove-hook 'find-file-hooks 'tramp-set-auto-save)))
 
 (defun tramp-run-test (switch filename)
   "Run `test' on the remote system, given a SWITCH and a FILENAME.
@@ -5532,6 +5588,7 @@ Maybe the different regular expressions need to be tuned.
                    (or user (user-login-name)) host method)
     (let ((process-environment (copy-sequence process-environment)))
       (setenv "TERM" tramp-terminal-type)
+      (setenv "PS1" "$ ")
       (let* ((default-directory (tramp-temporary-file-directory))
              ;; If we omit the conditional here, then we would use
              ;; `undecided-dos' in some cases.  With the conditional,
@@ -5608,6 +5665,7 @@ arguments, and xx will be used as the host name to connect to.
         (setq login-args (cons "-p" (cons (match-string 2 host) login-args)))
         (setq real-host (match-string 1 host)))
       (setenv "TERM" tramp-terminal-type)
+      (setenv "PS1" "$ ")
       (let* ((default-directory (tramp-temporary-file-directory))
              ;; If we omit the conditional, we would use
              ;; `undecided-dos' in some cases.  With the conditional,
@@ -5659,6 +5717,7 @@ prompt than you do, so it is not at all unlikely that the variable
                    (or user "<root>") method)
     (let ((process-environment (copy-sequence process-environment)))
       (setenv "TERM" tramp-terminal-type)
+      (setenv "PS1" "$ ")
       (let* ((default-directory (tramp-temporary-file-directory))
              ;; If we omit the conditional, we use `undecided-dos' in
              ;; some cases.  With the conditional, we use nil in these
@@ -5723,6 +5782,7 @@ log in as u2 to h2."
     (tramp-message 7 "Opening `%s' connection..." multi-method)
     (let ((process-environment (copy-sequence process-environment)))
       (setenv "TERM" tramp-terminal-type)
+      (setenv "PS1" "$ ")
       (let* ((default-directory (tramp-temporary-file-directory))
              ;; If we omit the conditional, we use `undecided-dos' in
              ;; some cases.  With the conditional, we use nil in these
@@ -6203,8 +6263,17 @@ locale to C and sets up the remote shell search path."
                                    "ln" tramp-remote-path nil)))
     (when ln
       (tramp-set-connection-property "ln" ln multi-method method user host)))
+  ;; Set uid and gid.
   (erase-buffer)
+  (tramp-send-command multi-method method user host "id -u; id -g")
+  (tramp-wait-for-output)
+  (goto-char (point-min))
+  (tramp-set-connection-property
+   "uid" (read (current-buffer)) multi-method method user host)
+  (tramp-set-connection-property
+   "gid" (read (current-buffer)) multi-method method user host)
   ;; Find the right encoding/decoding commands to use.
+  (erase-buffer)
   (unless (tramp-method-out-of-band-p multi-method method user host)
     (tramp-find-inline-encoding multi-method method user host))
   ;; If encoding/decoding command are given, test to see if they work.
@@ -6700,6 +6769,10 @@ Return ATTR."
   (unless (stringp (nth 8 attr))
     ;; Convert file mode bits to string.
     (setcar (nthcdr 8 attr) (tramp-file-mode-from-int (nth 8 attr))))
+  ;; Set file's gid change bit.
+  (setcar (nthcdr 9 attr)
+          (not (= (nth 3 attr)
+                  (tramp-get-remote-gid multi-method method user host))))
   ;; Set virtual device number.
   (setcar (nthcdr 11 attr)
           (tramp-get-device multi-method method user host))
@@ -6957,6 +7030,12 @@ If both MULTI-METHOD and METHOD are nil, do a lookup in
 (defun tramp-get-remote-ln (multi-method method user host)
   (tramp-get-connection-property "ln" nil multi-method method user host))
 
+(defun tramp-get-remote-uid (multi-method method user host)
+  (tramp-get-connection-property "uid" nil multi-method method user host))
+
+(defun tramp-get-remote-gid (multi-method method user host)
+  (tramp-get-connection-property "gid" nil multi-method method user host))
+
 ;; Get a property of a TRAMP connection.
 (defun tramp-get-connection-property
   (property default multi-method method user host)
@@ -6967,7 +7046,7 @@ If the value is not set for the connection, return `default'"
     (let (error)
       (condition-case nil
           (symbol-value (intern (concat "tramp-connection-property-" property)))
-        (error  default)))))
+        (error default)))))
 
 ;; Set a property of a TRAMP connection.
 (defun tramp-set-connection-property
@@ -7045,7 +7124,9 @@ as default."
     "Invoke `tramp-handle-make-auto-save-file-name' for tramp files."
     (if (and (buffer-file-name) (tramp-tramp-file-p (buffer-file-name)))
         (setq ad-return-value (tramp-handle-make-auto-save-file-name))
-      ad-do-it)))
+      ad-do-it))
+  (add-hook 'tramp-unload-hook
+            '(lambda () (ad-unadvise 'make-auto-save-file-name))))
 
 ;; In Emacs < 22 and XEmacs < 21.5 autosaved remote files have
 ;; permission 0666 minus umask. This is a security threat.
@@ -7069,7 +7150,10 @@ as default."
             (and (featurep 'xemacs)
                  (= emacs-major-version 21)
                  (> emacs-minor-version 4)))
-  (add-hook 'auto-save-hook 'tramp-set-auto-save-file-modes))
+  (add-hook 'auto-save-hook 'tramp-set-auto-save-file-modes)
+  (add-hook 'tramp-unload-hook
+            '(lambda ()
+               (remove-hook 'auto-save-hook 'tramp-set-auto-save-file-modes))))
 
 (defun tramp-subst-strs-in-string (alist string)
   "Replace all occurrences of the string FROM with TO in STRING.
@@ -7296,7 +7380,9 @@ Only works for Bourne-like shells."
               (setq ad-return-value (list name))))
         ;; If it is not a Tramp file, just run the original function.
         (let ((res ad-do-it))
-          (setq ad-return-value (or res (list name))))))))
+          (setq ad-return-value (or res (list name)))))))
+  (add-hook 'tramp-unload-hook
+            '(lambda () (ad-unadvise 'file-expand-wildcards))))
 
 ;; Tramp version is useful in a number of situations.
 
@@ -7521,6 +7607,25 @@ Therefore, the contents of files might be included in the debug buffer(s).")
 
 (defalias 'tramp-submit-bug 'tramp-bug)
 
+;; Checklist for `tramp-unload-hook'
+;; - Unload all `tramp-*' packages
+;; - Reset `file-name-handler-alist'
+;; - Cleanup hooks where Tramp functions are in
+;; - Cleanup advised functions
+;; - Cleanup autoloads
+;;;###autoload
+(defun tramp-unload-tramp ()
+  (interactive)
+  ;; When Tramp is not loaded yet, its autoloads are still active.
+  (tramp-unload-file-name-handler-alist)
+  ;; ange-ftp settings must be enabled.
+  (when (functionp 'tramp-ftp-enable-ange-ftp)
+    (funcall (symbol-function 'tramp-ftp-enable-ange-ftp)))
+  ;; `tramp-util' unloads also `tramp'.
+  (condition-case nil ;; maybe its not loaded yet.
+      (unload-feature (if (featurep 'tramp-util) 'tramp-util 'tramp) 'force)
+    (error nil)))
+
 (provide 'tramp)
 
 ;; Make sure that we get integration with the VC package.
@@ -7528,7 +7633,12 @@ Therefore, the contents of files might be included in the debug buffer(s).")
 ;; This must come after (provide 'tramp) because tramp-vc.el
 ;; requires tramp.
 (eval-after-load "vc"
-  '(require 'tramp-vc))
+  '(progn
+     (require 'tramp-vc)
+     (add-hook 'tramp-unload-hook
+               '(lambda ()
+                  (when (featurep 'tramp-vc)
+                    (unload-feature 'tramp-vc 'force))))))
 
 ;;; TODO:
 
diff --git a/lisp/net/trampver.el b/lisp/net/trampver.el
index 650f1a727a7..632d958249d 100644
--- a/lisp/net/trampver.el
+++ b/lisp/net/trampver.el
@@ -30,7 +30,7 @@
 ;; are auto-frobbed from configure.ac, so you should edit that file and run
 ;; "autoconf && ./configure" to change them.
 
-(defconst tramp-version "2.0.51"
+(defconst tramp-version "2.0.52"
   "This version of Tramp.")
 
 (defconst tramp-bug-report-address "tramp-devel@gnu.org"