Add Tramp sudoedit method

* doc/misc/tramp.texi (Quick Start Guide): New section "Using sudoedit".
(External methods) <sudoedit>: Describe.

* lisp/net/tramp-adb.el (tramp-adb-file-name-handler-alist):
* lisp/net/tramp-gvfs.el (tramp-gvfs-file-name-handler-alist):
* lisp/net/tramp-rclone.el (tramp-rclone-file-name-handler-alist):
* lisp/net/tramp-sh.el (tramp-sh-file-name-handler-alist)
* lisp/net/tramp-smb.el (tramp-smb-file-name-handler-alist):
Add handler.

* lisp/net/tramp-sh.el (tramp-sh-handle-set-file-uid-gid): Rename from
`tramp-sh-handle-set-file-uid-gid'.  Handle only remote file names.

* lisp/net/tramp-sudoedit.el: New file.

* lisp/net/tramp.el (tramp-file-name-for-operation): Handle also
`tramp-set-file-uid-gid'.
(tramp-set-file-uid-gid): New defun.
(tramp-get-local-uid, tramp-get-local-gid): Cache result.

* test/lisp/net/tramp-tests.el (tramp--test-sudoedit-p): New defun.
(tramp-test20-file-modes, tramp-test22-file-times)
(tramp--test-sudoedit-p): Use it.

1 files changed, 6 insertions, 0 deletions

diff --git a/etc/NEWS b/etc/NEWS
index 0624c5690bc..c88f6ef5ca4 100644
--- a/etc/NEWS
+++ b/etc/NEWS
@@ -865,6 +865,12 @@ or NextCloud hosted files and directories.
 storages via the 'rclone' program.  This feature is experimental.
 
 +++
+*** New connection method "sudoedit", which allows to edit local files
+with different user credentials.  Contrary to the "sudo" method, no
+session is run permanently in the background.  This is for security
+reasons.
+
++++
 *** Connection methods "obex" and "synce" are removed, because they
 are obsoleted in GVFS.