* net/tramp.el (tramp-set-file-uid-gid): Handle the case the

remote user is root, on the local host.
(tramp-local-host-p): Either the local user or the remote user
must be root.

2 files changed, 27 insertions, 14 deletions

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index 6a2f3ad06e7..b7168fffd3a 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,3 +1,10 @@
+2009-07-08  Michael Albinus  <michael.albinus@gmx.de>
+
+        * net/tramp.el (tramp-set-file-uid-gid): Handle the case the
+        remote user is root, on the local host.
+        (tramp-local-host-p): Either the local user or the remote user
+        must be root.  (Bug#3771)
+
 2009-07-08  Nick Roberts  <nickrob@snap.net.nz>
 
         * progmodes/gdb-mi.el (gdb): Remove description of
diff --git a/lisp/net/tramp.el b/lisp/net/tramp.el
index d95430d55d2..444f55ac5d2 100644
--- a/lisp/net/tramp.el
+++ b/lisp/net/tramp.el
@@ -2709,14 +2709,17 @@ and gid of the corresponding user is taken.  Both parameters must be integers."
   ;; the majority of cases.
   (if (file-remote-p filename)
       (with-parsed-tramp-file-name filename nil
-        (let ((uid (or (and (integerp uid) uid)
-                       (tramp-get-remote-uid v 'integer)))
-              (gid (or (and (integerp gid) gid)
-                       (tramp-get-remote-gid v 'integer))))
-          (tramp-send-command
-           v (format
-              "chown %d:%d %s" uid gid
-              (tramp-shell-quote-argument localname)))))
+        (if (and (zerop (user-uid)) (tramp-local-host-p v))
+            ;; If we are root on the local host, we can do it directly.
+            (tramp-set-file-uid-gid localname uid gid)
+          (let ((uid (or (and (integerp uid) uid)
+                         (tramp-get-remote-uid v 'integer)))
+                (gid (or (and (integerp gid) gid)
+                         (tramp-get-remote-gid v 'integer))))
+            (tramp-send-command
+             v (format
+                "chown %d:%d %s" uid gid
+                (tramp-shell-quote-argument localname))))))
 
     ;; We handle also the local part, because there doesn't exist
     ;; `set-file-uid-gid'.  On W32 "chown" might not work.
@@ -4395,7 +4398,7 @@ Returns a file name in `tramp-auto-save-directory' for autosaving this file."
                    (tramp-get-remote-gid v 'integer))))
 
       (if (and (tramp-local-host-p v)
-               ;; `file-writable-p' calls 'file-expand-file-name'.  We
+               ;; `file-writable-p' calls `file-expand-file-name'.  We
                ;; cannot use `tramp-run-real-handler' therefore.
                (let (file-name-handler-alist)
                  (and
@@ -4403,10 +4406,10 @@ Returns a file name in `tramp-auto-save-directory' for autosaving this file."
                   (or (file-directory-p localname)
                       (file-writable-p localname)))))
           ;; Short track: if we are on the local host, we can run directly.
-          (prog1
-              (tramp-run-real-handler
-               'write-region
-               (list start end localname append 'no-message lockname confirm))
+          (progn
+            (tramp-run-real-handler
+             'write-region
+             (list start end localname append 'no-message lockname confirm))
             (tramp-flush-file-property v localname))
 
         (let ((rem-dec (tramp-get-remote-coding v "remote-decoding"))
@@ -7190,7 +7193,10 @@ necessary only.  This function will be used in file name completion."
        (tramp-file-name-method vec)
        (tramp-file-name-user vec)
        host
-       (tramp-compat-temporary-file-directory))))))
+       (tramp-compat-temporary-file-directory)))
+     ;; On some systems, chown runs only for root.
+     (or (zerop (user-uid))
+         (zerop (tramp-get-remote-uid vec 'integer))))))
 
 ;; Variables local to connection.