Fix bug in Tramp argument computing

* lisp/net/tramp-sh.el (tramp-ssh-or-plink-options): Return always
a string.  (Bug#76553)

(cherry picked from commit c2d20946059bb78d7ab40060dbdc829c59a16bde)

diff --git a/lisp/net/tramp-sh.el b/lisp/net/tramp-sh.el
index c78234e57a33d9d65999d7796fb37d37b300dc76..03030f311f3c28fc5d60f28d515d305f76cdc501 100644 (file)
--- a/lisp/net/tramp-sh.el
+++ b/lisp/net/tramp-sh.el
@@ -4958,7 +4958,10 @@ Goes through the list `tramp-inline-compress-commands'."
         ;; ControlPersist option is introduced in OpenSSH 5.6.
         (when (and (not (eq tramp-use-connection-share 'suppress))
                     (tramp-ssh-option-exists-p vec "ControlPersist=no"))
-          " -o ControlPersist=no")))))))
+          " -o ControlPersist=no")))))
+
+   ;; Return a string, whatsoever.
+   (t "")))
 
 (defun tramp-scp-strict-file-name-checking (vec)
   "Return the strict file name checking argument of the local scp."