Split line.

dulwich/patch.py

@@ -83,7 +83,8 @@ def get_summary(commit):
     :param commit: Commit
     :return: Summary string
     """
-    return commit.message.decode(errors='replace').splitlines()[0].replace(" ", "-")
+    decoded = commit.message.decode(errors='replace')
+    return decoded.splitlines()[0].replace(" ", "-")
 
 
 #  Unified Diff