Only allow directories for directorylisting

servefile

@@ -878,6 +878,10 @@ class ServeFile():
 			FilePutter.maxUploadSize = self.maxUploadSize
 			handler = FilePutter
 		elif self.serveMode == self.MODE_LISTDIR:
+			if not os.path.exists(self.target):
+				raise ServeFileException("Error: Could not open file or directory.")
+			if not os.path.isdir(self.target):
+				raise ServeFileException("Error: '%s' is not a directory." % (self.target,))
 			handler = DirListingHandler
 			handler.targetDir = self.target