Allow explicit commit/rollback. Prevent multiple txn end. Add txn.changed().

1 files changed, 7 insertions, 0 deletions

diff --git a/dns/versioned.py b/dns/versioned.py
index e753438..e070c1a 100644
--- a/dns/versioned.py
+++ b/dns/versioned.py
@@ -90,6 +90,7 @@ class WritableVersion(Version):
         name = self._validate_name(name)
         if name in self.nodes:
             del self.nodes[name]
+            self.changed.add(name)
             return True
         return False
 
@@ -436,6 +437,12 @@ class Transaction(dns.transaction.Transaction):
     def _name_exists(self, name):
         return self.version.get_node(name) is not None
 
+    def _changed(self):
+        if self.read_only:
+            return False
+        else:
+            return len(self.version.changed) > 0
+
     def _end_transaction(self, commit):
         if self.read_only:
             self.zone._end_read(self)