[CORDA-2330] Turn on lenient mode in rpc serialization context. (#4409)

serialization/src/main/kotlin/net/corda/serialization/internal/ClientContexts.kt

@@ -21,5 +21,6 @@ val AMQP_RPC_CLIENT_CONTEXT = SerializationContextImpl(
         emptyMap(),
         true,
         SerializationContext.UseCase.RPCClient,
-        null
+        null,
+        lenientCarpenterEnabled = true
 )

serialization/src/test/kotlin/net/corda/serialization/internal/amqp/DeserializeQueryableStateTest.kt

@@ -0,0 +1,63 @@
+package net.corda.serialization.internal.amqp
+
+import net.corda.core.identity.AbstractParty
+import net.corda.core.schemas.MappedSchema
+import net.corda.core.schemas.PersistentState
+import net.corda.core.schemas.QueryableState
+import net.corda.core.serialization.SerializationContext
+import net.corda.core.serialization.SerializedBytes
+import net.corda.serialization.internal.AllWhitelist
+import net.corda.serialization.internal.SerializationContextImpl
+import net.corda.serialization.internal.amqp.testutils.*
+import net.corda.serialization.internal.carpenter.ClassCarpenterImpl
+import org.junit.Test
+
+data class TestState(override val participants: List<AbstractParty>): QueryableState {
+    override fun generateMappedObject(schema: MappedSchema): PersistentState {
+        throw NotImplementedError()
+    }
+    override fun supportedSchemas(): Iterable<MappedSchema> {
+        throw NotImplementedError()
+    }
+}
+
+/**
+ * A class loader that excludes [TestState].
+ */
+class ClassLoaderWithoutTestState(classLoader: ClassLoader): ClassLoader(classLoader) {
+    override fun loadClass(name: String?, resolve: Boolean): Class<*> {
+        if(name != null && name.contains("TestState")) {
+            throw ClassNotFoundException()
+        }
+        return super.loadClass(name, resolve)
+    }
+}
+
+class DeserializeQueryableStateTest {
+
+    /**
+     * Set `lenient` to false to reproduce CORDA-2330
+     * https://r3-cev.atlassian.net/browse/CORDA-2330
+     */
+    @Test
+    fun `should deserialize subclass of QueryableState that is not present in the class loader`() {
+
+        val lenient = true
+        val instance = TestState(listOf())
+        val serialized = TestSerializationOutput(false, testDefaultFactory()).serialize(instance)
+
+        val sf = SerializerFactoryBuilder.build(AllWhitelist, ClassCarpenterImpl(AllWhitelist, ClassLoaderWithoutTestState(ClassLoader.getSystemClassLoader()), lenient))
+
+        val context = SerializationContextImpl(
+                preferredSerializationVersion = amqpMagic,
+                deserializationClassLoader = ClassLoaderWithoutTestState(ClassLoader.getSystemClassLoader()),
+                whitelist = AllWhitelist,
+                properties = serializationProperties,
+                objectReferencesEnabled = false,
+                useCase = SerializationContext.UseCase.Testing,
+                encoding = null)
+        val bytes = SerializedBytes<QueryableState>(serialized.bytes)
+        // will throw when lenient is false
+        DeserializationInput(sf).deserialize(bytes, context)
+    }
+}