manually committed pull 221, update vars only if FieldStorage holds actually something, thanks Niphlod

VERSION

@@ -1 +1 @@
-Version 2.6.3-stable+timestamp.2013.09.20.21.27.35
+Version 2.6.3-stable+timestamp.2013.09.21.18.14.28

gluon/globals.py

@@ -215,7 +215,8 @@ class Request(Storage):
             and env.request_method in ('POST', 'PUT', 'DELETE', 'BOTH')):
             query_string = env.pop('QUERY_STRING',None)
             dpost = cgi.FieldStorage(fp=body, environ=env, keep_blank_values=1)
-            post_vars.update(dpost)
+            if len(dpost):
+                post_vars.update(dpost)
             if query_string is not None:
                 env['QUERY_STRING'] = query_string
             # The same detection used by FieldStorage to detect multipart POSTs