* lisp/net/tramp.el (tramp-debug-message):

`tramp-compat-main-thread' could be nil.

diff --git a/lisp/net/tramp.el b/lisp/net/tramp.el
index a8a927aea060dc34a8039e29c94d4c475afea905..5429cdf7fec3758d83c2f413eed69000f5cd7da8 100644 (file)
--- a/lisp/net/tramp.el
+++ b/lisp/net/tramp.el
@@ -1587,7 +1587,8 @@ ARGUMENTS to actually emit the message (if applicable)."
       (insert (format-time-string "%T." now))
       (insert (format "%06d " (nth 2 now))))
     ;; Threads.
-    (unless (eq (tramp-compat-current-thread) tramp-compat-main-thread)
+    (unless (or (null tramp-compat-main-thread)
+               (eq (tramp-compat-current-thread) tramp-compat-main-thread))
       (insert (format "%s " (tramp-compat-current-thread))))
     ;; Calling Tramp function.  We suppress compat and trace functions
     ;; from being displayed.