From b5af09200a8659c6438befe88b5bcfee5377c7c0 Mon Sep 17 00:00:00 2001
From: Thomas Heigl <thomas.heigl@gmail.com>
Date: Wed, 4 Nov 2020 10:35:31 +0100
Subject: [PATCH] #774 Do not re-use serializer instances for `Compatible` and
 `Tagged` serializers in `ReflectField`

---
 .../kryo/serializers/CompatibleFieldSerializer.java   |  8 ++------
 .../kryo/serializers/FieldSerializer.java             | 11 ++++++++---
 .../kryo/serializers/ReflectField.java                |  4 ++--
 .../kryo/serializers/TaggedFieldSerializer.java       |  6 +-----
 4 files changed, 13 insertions(+), 16 deletions(-)

diff --git a/src/com/esotericsoftware/kryo/serializers/CompatibleFieldSerializer.java b/src/com/esotericsoftware/kryo/serializers/CompatibleFieldSerializer.java
index 118fea06a..599787a1e 100644
--- a/src/com/esotericsoftware/kryo/serializers/CompatibleFieldSerializer.java
+++ b/src/com/esotericsoftware/kryo/serializers/CompatibleFieldSerializer.java
@@ -47,7 +47,7 @@
 public class CompatibleFieldSerializer<T> extends FieldSerializer<T> {
 	private static final int binarySearchThreshold = 32;
 
-	private CompatibleFieldSerializerConfig config;
+	private final CompatibleFieldSerializerConfig config;
 
 	public CompatibleFieldSerializer (Kryo kryo, Class type) {
 		this(kryo, type, new CompatibleFieldSerializerConfig());
@@ -56,6 +56,7 @@ public CompatibleFieldSerializer (Kryo kryo, Class type) {
 	public CompatibleFieldSerializer (Kryo kryo, Class type, CompatibleFieldSerializerConfig config) {
 		super(kryo, type, config);
 		this.config = config;
+		setReuseSerializers(false);
 	}
 
 	@Override
@@ -242,11 +243,6 @@ else if (compare > 0)
 		return fields;
 	}
 
-	@Override
-	boolean supportsReuse() {
-		return !config.readUnknownFieldData;
-	}
-
 	public CompatibleFieldSerializerConfig getCompatibleFieldSerializerConfig () {
 		return config;
 	}
diff --git a/src/com/esotericsoftware/kryo/serializers/FieldSerializer.java b/src/com/esotericsoftware/kryo/serializers/FieldSerializer.java
index ffb6957e9..7d73c044c 100644
--- a/src/com/esotericsoftware/kryo/serializers/FieldSerializer.java
+++ b/src/com/esotericsoftware/kryo/serializers/FieldSerializer.java
@@ -63,6 +63,7 @@ public class FieldSerializer<T> extends Serializer<T> {
 	final FieldSerializerConfig config;
 	final CachedFields cachedFields;
 	private final GenericsHierarchy genericsHierarchy;
+	private boolean reuseSerializers = true;
 
 	public FieldSerializer (Kryo kryo, Class type) {
 		this(kryo, type, new FieldSerializerConfig());
@@ -211,9 +212,13 @@ protected T createCopy (Kryo kryo, T original) {
 		return (T)kryo.newInstance(original.getClass());
 	}
 
-	/** If true, the serializer supports re-use of serializers for all instances of a field */
-	boolean supportsReuse() {
-		return true;
+	boolean getReuseSerializers() {
+		return reuseSerializers;
+	}
+
+	/** If true, {@link ReflectField}s re-use serializers for all instances of a field if the concrete value class is known */
+	void setReuseSerializers(boolean reuseSerializers) {
+		this.reuseSerializers = reuseSerializers;
 	}
 
 	@Override
diff --git a/src/com/esotericsoftware/kryo/serializers/ReflectField.java b/src/com/esotericsoftware/kryo/serializers/ReflectField.java
index c19d04510..2d4a23f84 100644
--- a/src/com/esotericsoftware/kryo/serializers/ReflectField.java
+++ b/src/com/esotericsoftware/kryo/serializers/ReflectField.java
@@ -73,7 +73,7 @@ public void write (Output output, Object object) {
 				if (serializer == null) {
 					serializer = kryo.getSerializer(concreteType);
 					// The concrete type of the field is known, always use the same serializer.
-					if (valueClass != null && this.fieldSerializer.supportsReuse()) this.serializer = serializer;
+					if (valueClass != null && this.fieldSerializer.getReuseSerializers()) this.serializer = serializer;
 				}
 				kryo.getGenerics().pushGenericType(genericType);
 				if (canBeNull) {
@@ -121,7 +121,7 @@ public void read (Input input, Object object) {
 				if (serializer == null) {
 					serializer = kryo.getSerializer(concreteType);
 					// The concrete type of the field is known, always use the same serializer.
-					if (valueClass != null && this.fieldSerializer.supportsReuse()) this.serializer = serializer;
+					if (valueClass != null && this.fieldSerializer.getReuseSerializers()) this.serializer = serializer;
 				}
 				kryo.getGenerics().pushGenericType(genericType);
 				if (canBeNull)
diff --git a/src/com/esotericsoftware/kryo/serializers/TaggedFieldSerializer.java b/src/com/esotericsoftware/kryo/serializers/TaggedFieldSerializer.java
index 4df4187f8..abdf77282 100644
--- a/src/com/esotericsoftware/kryo/serializers/TaggedFieldSerializer.java
+++ b/src/com/esotericsoftware/kryo/serializers/TaggedFieldSerializer.java
@@ -72,6 +72,7 @@ public TaggedFieldSerializer (Kryo kryo, Class type, TaggedFieldSerializerConfig
 		super(kryo, type, config);
 		this.config = config;
 		setAcceptsNull(true);
+		setReuseSerializers(false);
 	}
 
 	@Override
@@ -242,11 +243,6 @@ public T read (Kryo kryo, Input input, Class<? extends T> type) {
 		return object;
 	}
 
-	@Override
-	boolean supportsReuse() {
-		return !config.readUnknownTagData;
-	}
-
 	public TaggedFieldSerializerConfig getTaggedFieldSerializerConfig () {
 		return config;
 	}