--- lucene/MIGRATE.txt (revision 1637816)
+++ lucene/MIGRATE.txt (working copy)
@@ -73,3 +73,9 @@
situations where some documents do not have values for fields wrapped in other
ValueSources. Users who want to preserve the previous behavior may need to wrap
their ValueSources in a "DefFunction" along with a ConstValueSource of "0.0".
+## PayloadAttributeImpl.clone() (LUCENE-6055)
+PayloadAttributeImpl.clone() did a shallow clone which was incorrect, and was
+fixed to do a deep clone. If you require shallow cloning of the underlying bytes,
+you should override PayloadAttributeImpl.clone() to do a shallow clone instead.