1 files changed, 3 insertions, 0 deletions
diff --git a/Lib/urllib2.py b/Lib/urllib2.py
index 122f777..8b26971 100644
--- a/Lib/urllib2.py
+++ b/Lib/urllib2.py
@@ -226,6 +226,9 @@ class Request:
     # XXX these helper methods are lame
 
     def add_data(self, data):
+        if self.has_data():
+            raise TypeError("Request Obj already contains data: %s" %
+                            self.data)
         self.data = data
 
     def has_data(self):