* net/tramp.el (tramp-handle-start-file-process): Check only for

`remote-tty' process property.
(tramp-open-shell): Don't check for tty.
(tramp-open-connection-setup-interactive-shell): Set `remote-tty'
process property.

* progmodes/gdb-mi.el (gdb-init-1): Check also for tty on a remote
host.

1 files changed, 11 insertions, 11 deletions

diff --git a/lisp/net/tramp.el b/lisp/net/tramp.el
index 6256c8c631d..aca0238e5b6 100644
--- a/lisp/net/tramp.el
+++ b/lisp/net/tramp.el
@@ -4538,14 +4538,12 @@ beginning of local filename are not substituted."
           (with-current-buffer (tramp-get-connection-buffer v)
             (clear-visited-file-modtime)
             (narrow-to-region (point-max) (point-max)))
-          (if (stringp program)
-              ;; Send the command.  `tramp-send-command' opens a new
-              ;; connection.
+          (if command
+              ;; Send the command.
               (tramp-send-command v command nil t) ; nooutput
-            ;; Check, whether a pty is associated, and set it as
-            ;; process property.
-            (condition-case nil
-                (tramp-send-command-and-read v "echo \\\"`tty`\\\"")
+            ;; Check, whether a pty is associated.
+            (tramp-maybe-open-connection v)
+            (unless (process-get (tramp-get-connection-process v) 'remote-tty)
               (tramp-error
                v 'file-error "pty association is not supported for `%s'" name)))
           ;; Set query flag for this process.
@@ -6631,10 +6629,7 @@ file exists and nonzero exit status otherwise."
      vec (format "PS1=%s" (shell-quote-argument tramp-end-of-output)) t)
     (tramp-send-command vec "PS2=''" t)
     (tramp-send-command vec "PS3=''" t)
-    (tramp-send-command vec "PROMPT_COMMAND=''" t)
-    ;; Dump tty in the traces.
-    (when (>= tramp-verbose 9)
-      (tramp-send-command vec "tty" t))))
+    (tramp-send-command vec "PROMPT_COMMAND=''" t)))
 
 (defun tramp-find-shell (vec)
   "Opens a shell on the remote host which groks tilde expansion."
@@ -7071,6 +7066,11 @@ process to set up.  VEC specifies the connection."
   (when (string-match "^IRIX64" (tramp-get-connection-property vec "uname" ""))
     (tramp-send-command vec "set +H" t))
 
+  ;; Set `remote-tty' process property.
+  (ignore-errors
+    (let ((tty (tramp-send-command-and-read vec "echo \\\"`tty`\\\"")))
+      (unless (zerop (length tty)) (process-put proc 'remote-tty tty))))
+
   ;; Set the environment.
   (tramp-message vec 5 "Setting default environment")