Support conditional GET in testenv server.

* src/exc/server_error.py: Add exception for GET to HEAD fallback.
* src/server/http/http_server.py: Do not send body if 304 return
code requested for a file.

testenv/exc/server_error.py

@@ -6,6 +6,12 @@ class ServerError (Exception):
     def __init__(self, err_message):
         self.err_message = err_message
 
+class NoBodyServerError (Exception):
+    """ A custom exception which is raised by the test servers.
+    Used if no body should be sent in response. """
+
+    def __init__(self, err_message):
+        self.err_message = err_message
 
 class AuthError (ServerError):
     """ A custom exception raised byt he servers when authentication of the

testenv/server/http/http_server.py

@@ -1,5 +1,5 @@
 from http.server import HTTPServer, BaseHTTPRequestHandler
-from exc.server_error import ServerError, AuthError
+from exc.server_error import ServerError, AuthError, NoBodyServerError
 from socketserver import BaseServer
 from posixpath import basename, splitext
 from base64 import b64encode
@@ -201,6 +201,8 @@ class _Handler(BaseHTTPRequestHandler):
     def Response(self, resp_obj):
         self.send_response(resp_obj.response_code)
         self.finish_headers()
+        if resp_obj.response_code == 304:
+            raise NoBodyServerError("Conditional get falling to head")
         raise ServerError("Custom Response code sent.")
 
     def custom_response(self):
@@ -401,6 +403,9 @@ class _Handler(BaseHTTPRequestHandler):
                 except AuthError as ae:
                     print(ae.__str__())
                     return(None, None)
+                except NoBodyServerError as nbse:
+                    print(nbse.__str__())
+                    return(None, None)
                 except ServerError as se:
                     print(se.__str__())
                     return(content, None)