#2466: ismount now recognizes mount points user can't access.

Patch by Robin Roth, reviewed by Serhiy Storchaka, comment wording
tweaked by me.
diff --git a/Misc/ACKS b/Misc/ACKS
index 150d37a..0664e87 100644
--- a/Misc/ACKS
+++ b/Misc/ACKS
@@ -1258,6 +1258,7 @@
 Just van Rossum
 Hugo van Rossum
 Saskia van Rossum
+Robin Roth
 Clement Rouault
 Donald Wallace Rouse II
 Liam Routt
diff --git a/Misc/NEWS b/Misc/NEWS
index 6c78a19..974bf1a 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -38,6 +38,9 @@
 Library
 -------
 
+- Issue #2466: posixpath.ismount now correctly recognizes mount points which
+  the user does not have permission to access.
+
 - Issue #27773: Correct some memory management errors server_hostname in _ssl.wrap_socket().
 
 - Issue #26750: unittest.mock.create_autospec() now works properly for