A couple more test cases to ensure join() doesn't add an "extra" backslash
in the presence of empty-string arguments.
diff --git a/Lib/test/test_ntpath.py b/Lib/test/test_ntpath.py
index 98569f9..336e9e2 100644
--- a/Lib/test/test_ntpath.py
+++ b/Lib/test/test_ntpath.py
@@ -81,6 +81,8 @@
 tester("ntpath.join('', '', '', '', 'a')", 'a')
 tester("ntpath.join('a', '')", 'a\\')
 tester("ntpath.join('a', '', '', '', '')", 'a\\')
+tester("ntpath.join('a\\', '')", 'a\\')
+tester("ntpath.join('a\\', '', '', '', '')", 'a\\')
 
 tester("ntpath.normpath('A//////././//.//B')", r'A\B')
 tester("ntpath.normpath('A/./B')", r'A\B')