Merge from origin/emacs-27

8a92030f6a (origin/emacs-27) Fix hang in autorevert-tests.el

# Conflicts:
#	test/lisp/autorevert-tests.el

diff --cc test/lisp/autorevert-tests.el
index 45cf635396091bb45e446b5cc666be0fcab4a9c6,8b8313df0150b7d3ce96c0684325c899a71906fd..5f27c2e38a6ff020adeb4f1129dffc47fa387441
--- 1/test/lisp/autorevert-tests.el
--- 2/test/lisp/autorevert-tests.el
+++ b/test/lisp/autorevert-tests.el
@@@ -132,10 -130,12 +132,12 @@@ This expects `auto-revert--messages' t
                  (null (string-match
                         (format-message
                          "Reverting buffer `%s'\\." (buffer-name buffer))
 -                       auto-revert--messages)))
 +                       (or auto-revert--messages ""))))
-       (if (with-current-buffer buffer auto-revert-use-notify)
+       (if (and (or file-notify--library
+                    (file-remote-p temporary-file-directory))
+                (with-current-buffer buffer auto-revert-use-notify))
 -          (read-event nil nil 0.1)
 -        (sleep-for 0.1)))))
 +          (read-event nil nil 0.05)
 +        (sleep-for 0.05)))))
  
  (defmacro auto-revert--deftest-remote (test docstring)
    "Define ert `TEST-remote' for remote files."