Improve the doc string of w32notify-valid-p

* src/w32notify.c (Fw32notify_valid_p): Mention in the doc string
that removing a watch makes its object invalid.

1 files changed, 2 insertions, 1 deletions

diff --git a/src/w32notify.c b/src/w32notify.c
index efd9e56e105..a6b5c1908a1 100644
--- a/src/w32notify.c
+++ b/src/w32notify.c
@@ -649,7 +649,8 @@ DEFUN ("w32notify-valid-p", Fw32notify_valid_p, Sw32notify_valid_p, 1, 1, 0,
 WATCH-DESCRIPTOR should be an object returned by `w32notify-add-watch'.
 
 A watch can become invalid if the directory it watches is deleted, or if
-the watcher thread exits abnormally for any other reason.  */)
+the watcher thread exits abnormally for any other reason.  Removing the
+watch by calling `w32notify-rm-watch' also makes it invalid.  */)
      (Lisp_Object watch_descriptor)
 {
   Lisp_Object watch_object = Fassoc (watch_descriptor, watch_list);