more fixes for correct behavior with non-existent files

kippo/commands/fs.py

@@ -32,7 +32,7 @@ class command_cd(HoneyPotCommand):
         try:
             newpath = self.fs.resolve_path(path, self.honeypot.cwd)
             newdir = self.fs.get_path(newpath)
-        except IndexError:
+        except:
             newdir = None
         if path == "-":
             self.writeln('bash: cd: OLDPWD not set')

kippo/core/fs.py

@@ -97,7 +97,7 @@ class HoneyPotFilesystem(object):
                     ok = True
                     break
             if not ok:
-               return None
+               raise FileNotFound
         return cwd[A_CONTENTS]
 
     def exists(self, path):
@@ -182,7 +182,10 @@ class HoneyPotFilesystem(object):
     def is_dir(self, path):
         if path == '/':
             return True
-        dir = self.get_path(os.path.dirname(path))
+        try:
+            dir = self.get_path(os.path.dirname(path))
+        except: 
+            dir = None
         if dir is None:
             return False
         l = [x for x in dir