Fix a problem with OpenSSH 7 in Tramp

* lisp/net/tramp-sh.el (tramp-ssh-controlmaster-options): Set also
"ConnectTimeout" during test.  Otherwise, OpenSSH 7 will hang.

1 files changed, 3 insertions, 1 deletions

diff --git a/lisp/net/tramp-sh.el b/lisp/net/tramp-sh.el
index e61b0ce526a..9b001a90e78 100644
--- a/lisp/net/tramp-sh.el
+++ b/lisp/net/tramp-sh.el
@@ -4592,8 +4592,10 @@ Goes through the list `tramp-inline-compress-commands'."
                 (with-temp-buffer
                   ;; We use a non-existing IP address, in order to
                   ;; avoid useless connections, and DNS timeouts.
+                  ;; Setting ConnectTimeout is needed since OpenSSH 7.
                   (tramp-call-process
-                   vec "ssh" nil t nil "-o" "ControlPath=%C" "0.0.0.1")
+                   vec "ssh" nil t nil
+                   "-o" "ConnectTimeout=1" "-o" "ControlPath=%C" "0.0.0.1")
                   (goto-char (point-min))
                   (setq tramp-ssh-controlmaster-options
                         (concat tramp-ssh-controlmaster-options