Fixed http status code when requesting a non-existing static page using Tordado web server. Fixed #1161.

CHANGELOG

@@ -8,6 +8,10 @@ Version 1.5.1 (unreleased)
 ==========================
 [https://github.com/OpenSlides/OpenSlides/issues?milestone=15]
 
+Other:
+- Fixed http status code when requesting a non-existing static page using
+  Tordado web server.
+
 
 Version 1.5 (2013-11-25)
 ========================

openslides/utils/tornado_webserver.py

@@ -43,10 +43,10 @@ class DjangoStaticFileHandler(StaticFileHandler):
         #     a shared root prefix
         #   - we do not handle self.default_filename (we do not use it and it
         #     does not make much sense here anyway)
-        if not os.path.exists(absolute_path):
+        if absolute_path is None or not os.path.exists(absolute_path):
             raise HTTPError(404)
         if not os.path.isfile(absolute_path):
-            raise HTTPError(403, "%s is not a file", self.path)
+            raise HTTPError(403, 'The requested resource is not a file.')
         return absolute_path