Merge branch '2.20' into 2.x

Author: cowtowncoder

release-notes/CREDITS-2.x

@@ -393,6 +393,9 @@ Rafael Winterhalter (@raphw)
  * Reported #589: AvroSchema: Does not include base class for records
    with subclasses
   (2.19.1)
+ * Reported #601: Jackson subtype Avro schema unions are non-deterministic and
+   therefore incompatible with each other
+  (2.20.1)
 
 Brian Gruber (@bgruber)
  * Reported #431: (cbor) Negative `BigInteger` values not encoded/decoded correctly
@@ -412,3 +415,8 @@ Fawzi Essam (@iifawzi)
 Oleg Koretsky (@Radiokot)
  * Contributed #603 (cbor) Add support for writing unsigned numbers to CBOR
   (2.20.0)
+
+Vincent Eigenberger (@beseder1)
+ * Contributed fix for #601: Jackson subtype Avro schema unions are non-deterministic
+   and therefore incompatible with each other
+  (2.20.1)

release-notes/VERSION-2.x

@@ -18,6 +18,13 @@ Active maintainers:
 
 No changes since 2.20
 
+2.20.1 (not yet released)
+
+#601: Jackson subtype Avro schema unions are non-deterministic and therefore
+  incompatible with each other
+ (reported by Raphael W)
+ (fix by Vincent E)
+
 2.20.0 (28-Aug-2025)
 
 #137: (cbor) Allow exposing CBOR "undefined" value as `JsonToken.VALUE_EMBEDDED_OBJECT`;