Update release notes wrt #225

Author: Tatu Saloranta

pom.xml

@@ -130,7 +130,7 @@
 	      <artifactId>maven-surefire-plugin</artifactId>
 	      <configuration>
 		<excludes>
-		  <exclude>com/fasterxml/jackson/**/failing/*.java</exclude>
+		  <exclude>com/fasterxml/jackson/**/failing/*</exclude>
 		</excludes>
 	      </configuration>
 	    </plugin>

release-notes/CREDITS-2.x

@@ -11,3 +11,6 @@ Stéphane B (StephaneBg@github)
 * Submitted fix for #176: Version 2.9.7 breaks compatibility with Android minSdk < 24
  (2.10.1)
 
+Alain Lehmann (ciderale@github)
+* Contributed fix for #225: Don't instantiate new instances of Kotlin singleton objects
+ (2.10.1)

release-notes/VERSION-2.x

@@ -8,6 +8,8 @@ Project: jackson-module-kotlin
 
 #176: Version 2.9.7 breaks compatibility with Android minSdk < 24
  (reported jurriaan@github, fix submitted by Stéphane B)
+#225: Don't instantiate new instances of Kotlin singleton objects
+ (reported by Dico200@github; fix by Alain L)
 - Make byte code target 1.8 (can't do many things with 1.7 anyway)
 
 2.10.0 (26-Sep-2019)

src/main/kotlin/com/fasterxml/jackson/module/kotlin/KotlinBeanDeserializerModifier.kt

@@ -5,22 +5,25 @@ import com.fasterxml.jackson.databind.DeserializationConfig
 import com.fasterxml.jackson.databind.JsonDeserializer
 import com.fasterxml.jackson.databind.deser.BeanDeserializerModifier
 
+// [module-kotlin#225]: keep Kotlin singletons as singletons
 object KotlinBeanDeserializerModifier: BeanDeserializerModifier() {
     override fun modifyDeserializer(
             config: DeserializationConfig,
             beanDesc: BeanDescription,
             deserializer: JsonDeserializer<*>
-    ) = super.modifyDeserializer(config, beanDesc, deserializer)
-            .maybeSingletonDeserializer(objectSingletonInstance(beanDesc.beanClass))
-}
-
-fun JsonDeserializer<*>.maybeSingletonDeserializer(singleton: Any?) = when (singleton) {
-    null -> this
-    else -> this.asSingletonDeserializer(singleton)
+    ): JsonDeserializer<out Any> {
+        val modifiedFromParent = super.modifyDeserializer(config, beanDesc, deserializer)
+	val objectSingletonInstance = objectSingletonInstance(beanDesc.beanClass)
+        return if (objectSingletonInstance != null) {
+            KotlinObjectSingletonDeserializer(objectSingletonInstance, modifiedFromParent)
+        } else {
+            modifiedFromParent
+        }
+    }
 }
 
 private fun objectSingletonInstance(beanClass: Class<*>): Any? = if (!beanClass.isKotlinClass()) {
     null
 } else {
     beanClass.kotlin.objectInstance
-}
+}

src/main/kotlin/com/fasterxml/jackson/module/kotlin/KotlinModule.kt

@@ -43,6 +43,7 @@ class KotlinModule(val reflectionCacheSize: Int = 512, val nullToEmptyCollection
 
         context.addValueInstantiators(KotlinInstantiators(cache, nullToEmptyCollection, nullToEmptyMap))
 
+        // [module-kotlin#225]: keep Kotlin singletons as singletons
         context.addBeanDeserializerModifier(KotlinBeanDeserializerModifier)
 
         fun addMixIn(clazz: Class<*>, mixin: Class<*>) {

src/test/kotlin/com/fasterxml/jackson/module/kotlin/failing/Github160.kt renamed to src/test/kotlin/com/fasterxml/jackson/module/kotlin/test/failing/Github160.kt

@@ -1,4 +1,4 @@
-package com.fasterxml.jackson.module.kotlin.test
+package com.fasterxml.jackson.module.kotlin.test.failing
 
 import com.fasterxml.jackson.databind.MapperFeature
 import com.fasterxml.jackson.module.kotlin.jacksonObjectMapper

src/test/kotlin/com/fasterxml/jackson/module/kotlin/failing/GithubDatabind1329.kt renamed to src/test/kotlin/com/fasterxml/jackson/module/kotlin/test/failing/GithubDatabind1329.kt

@@ -1,4 +1,4 @@
-package com.fasterxml.jackson.module.kotlin.test
+package com.fasterxml.jackson.module.kotlin.test.failing
 
 import com.fasterxml.jackson.annotation.JsonSubTypes
 import com.fasterxml.jackson.annotation.JsonTypeInfo