Support remote editing in emacsclient via Tramp

* lib-src/emacsclient.c (main, decode_options)
(print_help_and_exit, longopts): New option '--tramp' / '-T' which
specifies how emacs should use tramp to find remote files.

* doc/emacs/misc.texi (TCP Emacs server): New subsection describing
the various knobs to tune server.el for TCP opereation.
(emacsclient Options): Reference "TCP Emacs server" from description of
--server-file.  Document the new '--tramp' / '-T' options.
* doc/emacs/emacs.texi (Top): Update the top-level menu.

* etc/NEWS: Mention the new option.

1 files changed, 18 insertions, 2 deletions

diff --git a/lib-src/emacsclient.c b/lib-src/emacsclient.c
index 7b735dfb05d..c21ee6bd395 100644
--- a/lib-src/emacsclient.c
+++ b/lib-src/emacsclient.c
@@ -149,6 +149,9 @@ const char *socket_name = NULL;
 /* If non-NULL, the filename of the authentication file.  */
 const char *server_file = NULL;
 
+/* If non-NULL, the tramp prefix emacs must use to find the files.  */
+const char *tramp_prefix = NULL;
+
 /* PID of the Emacs server process.  */
 int emacs_pid = 0;
 
@@ -178,6 +181,7 @@ struct option longopts[] =
   { "server-file",      required_argument, NULL, 'f' },
   { "display",  required_argument, NULL, 'd' },
   { "parent-id", required_argument, NULL, 'p' },
+  { "tramp",    required_argument, NULL, 'T' },
   { 0, 0, 0, 0 }
 };
 
@@ -468,14 +472,15 @@ static void
 decode_options (int argc, char **argv)
 {
   alternate_editor = egetenv ("ALTERNATE_EDITOR");
+  tramp_prefix = egetenv ("EMACSCLIENT_TRAMP");
 
   while (1)
     {
       int opt = getopt_long_only (argc, argv,
 #ifndef NO_SOCKETS_IN_FILE_SYSTEM
-                             "VHnequa:s:f:d:F:tc",
+                             "VHnequa:s:f:d:F:tcT:",
 #else
-                             "VHnequa:f:d:F:tc",
+                             "VHnequa:f:d:F:tcT:",
 #endif
                              longopts, 0);
 
@@ -554,6 +559,10 @@ decode_options (int argc, char **argv)
           frame_parameters = optarg;
           break;
 
+        case 'T':
+          tramp_prefix = optarg;
+          break;
+
         default:
           message (true, "Try '%s --help' for more information\n", progname);
           exit (EXIT_FAILURE);
@@ -654,6 +663,9 @@ The following OPTIONS are accepted:\n\
                         Editor to fallback to if the server is not running\n"
 "                       If EDITOR is the empty string, start Emacs in daemon\n\
                         mode and try connecting again\n"
+"-T PREFIX, --tramp=PREFIX\n\
+                        PREFIX to prepend to filenames sent by emacsclient\n\
+                        for locating files remotely via Tramp\n"
 "\n\
 Report bugs with M-x report-emacs-bug.\n");
   exit (EXIT_SUCCESS);
@@ -1687,6 +1699,8 @@ main (int argc, char **argv)
         }
     }
   send_to_emacs (emacs_socket, "-dir ");
+  if (tramp_prefix)
+    quote_argument (emacs_socket, tramp_prefix);
   quote_argument (emacs_socket, cwd);
   send_to_emacs (emacs_socket, "/");
   send_to_emacs (emacs_socket, " ");
@@ -1791,6 +1805,8 @@ main (int argc, char **argv)
 #endif
 
           send_to_emacs (emacs_socket, "-file ");
+          if (tramp_prefix && file_name_absolute_p (argv[i]))
+            quote_argument (emacs_socket, tramp_prefix);
           quote_argument (emacs_socket, argv[i]);
           send_to_emacs (emacs_socket, " ");
         }