only check listdir on dirs

is_hidden is called with files, not just dirs

IPython/html/utils.py

@@ -1,135 +1,137 b''
 """Notebook related utilities
 
 Authors:
 
 * Brian Granger
 """
 
 #-----------------------------------------------------------------------------
 #  Copyright (C) 2011  The IPython Development Team
 #
 #  Distributed under the terms of the BSD License.  The full license is in
 #  the file COPYING, distributed as part of this software.
 #-----------------------------------------------------------------------------
 
 from __future__ import print_function
 
 import os
 import stat
 
 try:
     from urllib.parse import quote, unquote
 except ImportError:
     from urllib import quote, unquote
 
 from IPython.utils import py3compat
 
 # UF_HIDDEN is a stat flag not defined in the stat module.
 # It is used by BSD to indicate hidden files.
 UF_HIDDEN = getattr(stat, 'UF_HIDDEN', 32768)
 
 #-----------------------------------------------------------------------------
 # Imports
 #-----------------------------------------------------------------------------
 
 def url_path_join(*pieces):
     """Join components of url into a relative url
 
     Use to prevent double slash when joining subpath. This will leave the
     initial and final / in place
     """
     initial = pieces[0].startswith('/')
     final = pieces[-1].endswith('/')
     stripped = [s.strip('/') for s in pieces]
     result = '/'.join(s for s in stripped if s)
     if initial: result = '/' + result
     if final: result = result + '/'
     if result == '//': result = '/'
     return result
 
 def path2url(path):
     """Convert a local file path to a URL"""
     pieces = [ quote(p) for p in path.split(os.sep) ]
     # preserve trailing /
     if pieces[-1] == '':
         pieces[-1] = '/'
     url = url_path_join(*pieces)
     return url
 
 def url2path(url):
     """Convert a URL to a local file path"""
     pieces = [ unquote(p) for p in url.split('/') ]
     path = os.path.join(*pieces)
     return path
     
 def url_escape(path):
     """Escape special characters in a URL path
     
     Turns '/foo bar/' into '/foo%20bar/'
     """
     parts = py3compat.unicode_to_str(path).split('/')
     return u'/'.join([quote(p) for p in parts])
 
 def url_unescape(path):
     """Unescape special characters in a URL path
     
     Turns '/foo%20bar/' into '/foo bar/'
     """
     return u'/'.join([
         py3compat.str_to_unicode(unquote(p))
         for p in py3compat.unicode_to_str(path).split('/')
     ])
 
 def is_hidden(abs_path, abs_root=''):
     """Is a file hidden or contained in a hidden directory?
     
     This will start with the rightmost path element and work backwards to the
     given root to see if a path is hidden or in a hidden directory. Hidden is
     determined by either name starting with '.' or the UF_HIDDEN flag as 
     reported by stat.
     
     Parameters
     ----------
     abs_path : unicode
         The absolute path to check for hidden directories.
     abs_root : unicode
         The absolute path of the root directory in which hidden directories
         should be checked for.
     """
     if not abs_root:
         abs_root = abs_path.split(os.sep, 1)[0] + os.sep
     inside_root = abs_path[len(abs_root):]
     if any(part.startswith('.') for part in inside_root.split(os.sep)):
         return True
 
-    # check that path can be listed
+    # check that dirs can be listed
+    # may fail on Windows junctions or non-user-readable dirs
+    if os.path.isdir(abs_path):
     try:
         os.listdir(abs_path)
-    except Exception:
+        except OSError:
         return True
     
     # check UF_HIDDEN on any location up to root
     path = abs_path
     while path and path.startswith(abs_root) and path != abs_root:
         try:
             # may fail on Windows junctions
             st = os.stat(path)
-        except Exception:
+        except OSError:
             return True
         if getattr(st, 'st_flags', 0) & UF_HIDDEN:
             return True
         path = os.path.dirname(path)
 
     return False
 
 def to_os_path(path, root=''):
     """Convert an API path to a filesystem path
     
     If given, root will be prepended to the path.
     root must be a filesystem path already.
     """
     parts = path.strip('/').split('/')
     parts = [p for p in parts if p != ''] # remove duplicate splits
     path = os.path.join(root, *parts)
     return path