Make deltify default to True.

dulwich/client.py

@@ -1043,7 +1043,8 @@ class LocalGitClient(GitClient):
             # Note that the client still expects a 0-object pack in most cases.
             if objects_iter is None:
                 return FetchPackResult(None, symrefs, agent)
-            write_pack_objects(ProtocolFile(None, pack_data), objects_iter)
+            protocol = ProtocolFile(None, pack_data)
+            write_pack_objects(protocol, objects_iter)
             return FetchPackResult(r.get_refs(), symrefs, agent)
 
     def get_refs(self, path):

dulwich/pack.py

@@ -1579,7 +1579,7 @@ def deltify_pack_objects(objects, window_size=None):
             possible_bases.pop()
 
 
-def write_pack_objects(f, objects, delta_window_size=None, deltify=False):
+def write_pack_objects(f, objects, delta_window_size=None, deltify=None):
     """Write a new pack data file.
 
     :param f: File to write to
@@ -1590,6 +1590,8 @@ def write_pack_objects(f, objects, delta_window_size=None, deltify=False):
     :param deltify: Whether to deltify objects
     :return: Dict mapping id -> (offset, crc32 checksum), pack checksum
     """
+    if deltify is None:
+        deltify = True
     if deltify:
         pack_contents = deltify_pack_objects(objects, delta_window_size)
     else: