Doc fix.

1 files changed, 4 insertions, 2 deletions

diff --git a/lisp/subr.el b/lisp/subr.el
index ac2d3117623..cdbb06b4b5d 100644
--- a/lisp/subr.el
+++ b/lisp/subr.el
@@ -960,10 +960,12 @@ See also `with-temp-buffer'."
               (kill-buffer ,temp-buffer))))))
 
 (defmacro with-temp-message (message &rest body)
-  "Display MESSAGE temporarily while BODY is evaluated.
+  "Display MESSAGE temporarily if non-nil while BODY is evaluated.
 The original message is restored to the echo area after BODY has finished.
 The value returned is the value of the last form in BODY.
-MESSAGE is written to the message log buffer if `message-log-max' is non-nil."
+MESSAGE is written to the message log buffer if `message-log-max' is non-nil.
+If MESSAGE is nil, the echo area and message log buffer are unchanged.
+Use a MESSAGE of \"\" to temporarily clear the echo area."
   (let ((current-message (make-symbol "current-message"))
         (temp-message (make-symbol "with-temp-message")))
     `(let ((,temp-message ,message)