Fixed #3912 - Added simple type checking to template.Context.update() to help debugging broken context processors. Thanks Jeremy Dunck

git-svn-id: http://code.djangoproject.com/svn/django/trunk@8181 bcc190cf-cafb-0310-a4f2-bffc1f526a37

django/template/context.py

@@ -62,6 +62,8 @@ class Context(object):
 
     def update(self, other_dict):
         "Like dict.update(). Pushes an entire dictionary's keys and values onto the context."
+        if not hasattr(other_dict, '__getitem__'): 
+            raise TypeError('other_dict must be a mapping (dictionary-like) object.')
         self.dicts = [other_dict] + self.dicts
         return other_dict