diff -r 463df2986814 -r 052351e3e1cd mercurial/hgweb/common.py
--- a/mercurial/hgweb/common.py	Sat Mar 03 14:21:47 2018 -0500
+++ b/mercurial/hgweb/common.py	Sat Mar 03 12:34:35 2018 -0500
@@ -138,7 +138,7 @@
     """Determine if a path is safe to use for filesystem access."""
     parts = path.split('/')
     for part in parts:
-        if (part in ('', os.curdir, os.pardir) or
+        if (part in ('', os.curdir, pycompat.ospardir) or
             pycompat.ossep in part or
             pycompat.osaltsep is not None and pycompat.osaltsep in part):
             return False