Improve user name completion in Tramp

* lisp/net/tramp.el (tramp-parse-passwd, tramp-parse-etc-group):
Call also "getent passwd" or "getent group", if possible.
(tramp-parse-putty): Cache the result.

3 files changed, 25 insertions, 18 deletions

diff --git a/lisp/net/tramp-cmds.el b/lisp/net/tramp-cmds.el
index f9b66d43074..5e9af0b18eb 100644
--- a/lisp/net/tramp-cmds.el
+++ b/lisp/net/tramp-cmds.el
@@ -145,7 +145,7 @@ This includes password cache, file cache, connection cache, buffers."
   "Kill all remote buffers."
   (interactive)
 
-  ;; Remove all Tramp related buffers.
+  ;; Remove all Tramp related connections.
   (tramp-cleanup-all-connections)
 
   ;; Remove all buffers with a remote default-directory.
diff --git a/lisp/net/tramp-sh.el b/lisp/net/tramp-sh.el
index baebb13dd22..ab4f07fc020 100644
--- a/lisp/net/tramp-sh.el
+++ b/lisp/net/tramp-sh.el
@@ -5739,7 +5739,5 @@ function cell is returned to be applied on a buffer."
 ;;   rsync).
 ;; * Keep a second connection open for out-of-band methods like scp or
 ;;   rsync.
-;; * Check, whether we could also use "getent passwd" and "getent
-;;   group" for user/group name completion.
 
 ;;; tramp-sh.el ends here
diff --git a/lisp/net/tramp.el b/lisp/net/tramp.el
index e52f1958592..4543c0d1a47 100644
--- a/lisp/net/tramp.el
+++ b/lisp/net/tramp.el
@@ -1048,7 +1048,7 @@ entry does not exist, return nil."
          (replace-regexp-in-string "^tramp-" "" (symbol-name param))))
     (if (tramp-connection-property-p vec hash-entry)
         ;; We use the cached property.
-        (tramp-get-connection-property  vec hash-entry nil)
+        (tramp-get-connection-property vec hash-entry nil)
       ;; Use the static value from `tramp-methods'.
       (let ((methods-entry
              (assoc param (assoc (tramp-file-name-method vec) tramp-methods))))
@@ -2624,17 +2624,18 @@ User is always nil."
    (tramp-parse-group
     (concat "^\\(" tramp-ipv6-regexp "\\|" tramp-host-regexp "\\)") 1 " \t"))
 
-;; For su-alike methods it would be desirable to return "root@localhost"
-;; as default.  Unfortunately, we have no information whether any user name
-;; has been typed already.  So we use `tramp-current-user' as indication,
-;; assuming it is set in `tramp-completion-handle-file-name-all-completions'.
 ;;;###tramp-autoload
 (defun tramp-parse-passwd (filename)
   "Return a list of (user host) tuples allowed to access.
 Host is always \"localhost\"."
-  (if (zerop (length tramp-current-user))
-      '(("root" nil))
-    (tramp-parse-file filename 'tramp-parse-passwd-group)))
+  (with-tramp-connection-property nil "parse-passwd"
+    (if (executable-find "getent")
+        (with-temp-buffer
+          (when (zerop (tramp-call-process nil "getent" nil t nil "passwd"))
+            (goto-char (point-min))
+            (loop while (not (eobp)) collect
+                  (tramp-parse-etc-group-group))))
+      (tramp-parse-file filename 'tramp-parse-passwd-group))))
 
 (defun tramp-parse-passwd-group ()
    "Return a (user host) tuple allowed to access.
@@ -2650,7 +2651,14 @@ Host is always \"localhost\"."
 (defun tramp-parse-etc-group (filename)
   "Return a list of (group host) tuples allowed to access.
 Host is always \"localhost\"."
-  (tramp-parse-file filename 'tramp-parse-etc-group-group))
+  (with-tramp-connection-property nil "parse-group"
+    (if (executable-find "getent")
+        (with-temp-buffer
+          (when (zerop (tramp-call-process nil "getent" nil t nil "group"))
+            (goto-char (point-min))
+            (loop while (not (eobp)) collect
+                  (tramp-parse-etc-group-group))))
+      (tramp-parse-file filename 'tramp-parse-etc-group-group))))
 
 (defun tramp-parse-etc-group-group ()
    "Return a (group host) tuple allowed to access.
@@ -2686,12 +2694,13 @@ User may be nil."
   "Return a list of (user host) tuples allowed to access.
 User is always nil."
   (if (memq system-type '(windows-nt))
-      (with-temp-buffer
-        (when (zerop (tramp-call-process
-                      nil "reg" nil t nil "query" registry-or-dirname))
-          (goto-char (point-min))
-          (loop while (not (eobp)) collect
-                (tramp-parse-putty-group registry-or-dirname))))
+      (with-tramp-connection-property nil "parse-putty"
+        (with-temp-buffer
+          (when (zerop (tramp-call-process
+                        nil "reg" nil t nil "query" registry-or-dirname))
+            (goto-char (point-min))
+            (loop while (not (eobp)) collect
+                  (tramp-parse-putty-group registry-or-dirname)))))
     ;; UNIX case.
     (tramp-parse-shostkeys-sknownhosts
      registry-or-dirname (concat "^\\(" tramp-host-regexp "\\)$"))))