raise ValueError if the argument to node.replace_rdataset() is not an rdataset

1 files changed, 2 insertions, 0 deletions

diff --git a/dns/node.py b/dns/node.py
index d8eb482..32f9c08 100644
--- a/dns/node.py
+++ b/dns/node.py
@@ -167,6 +167,8 @@ class Node(object):
         at the node, it stores I{replacement} itself.
         """
 
+        if not isinstance(replacement, dns.rdataset.Rdataset):
+            raise ValueError, 'replacement is not an rdataset'
         self.delete_rdataset(replacement.rdclass, replacement.rdtype,
                              replacement.covers)
         self.rdatasets.append(replacement)