Upgrade to the latest Kotlin

* Fix more recursive generics on factory methods
See https://jira.spring.io/browse/INT-4458

**Cherry-pick to 5.0.x**

Author: artembilan

build.gradle

@@ -1,5 +1,5 @@
 buildscript {
-	ext.kotlinVersion = '1.2.41'
+	ext.kotlinVersion = '1.2.51'
 	repositories {
 		maven { url 'https://repo.spring.io/plugins-release' }
 	}

spring-integration-core/src/main/java/org/springframework/integration/dsl/Channels.java

@@ -96,20 +96,19 @@ public RendezvousChannelSpec rendezvous(String id) {
 		return MessageChannels.rendezvous(id);
 	}
 
-	public PublishSubscribeChannelSpec<? extends PublishSubscribeChannelSpec<?>>  publishSubscribe() {
+	public PublishSubscribeChannelSpec<?>  publishSubscribe() {
 		return MessageChannels.publishSubscribe();
 	}
 
-	public PublishSubscribeChannelSpec<? extends PublishSubscribeChannelSpec<?>> publishSubscribe(Executor executor) {
+	public PublishSubscribeChannelSpec<?> publishSubscribe(Executor executor) {
 		return MessageChannels.publishSubscribe(executor);
 	}
 
-	public PublishSubscribeChannelSpec<? extends PublishSubscribeChannelSpec<?>> publishSubscribe(String id,
-			Executor executor) {
+	public PublishSubscribeChannelSpec<?> publishSubscribe(String id, Executor executor) {
 		return MessageChannels.publishSubscribe(id, executor);
 	}
 
-	public PublishSubscribeChannelSpec<? extends PublishSubscribeChannelSpec<?>> publishSubscribe(String id) {
+	public PublishSubscribeChannelSpec<?> publishSubscribe(String id) {
 		return MessageChannels.publishSubscribe(id);
 	}
 

spring-integration-core/src/main/java/org/springframework/integration/dsl/MessageChannels.java

@@ -69,6 +69,7 @@ public static QueueChannelSpec.MessageStoreSpec queue(ChannelMessageStore messag
 
 	public static QueueChannelSpec.MessageStoreSpec queue(String id, ChannelMessageStore messageGroupStore,
 			Object groupId) {
+
 		return queue(messageGroupStore, groupId).id(id);
 	}
 
@@ -102,26 +103,24 @@ public static PriorityChannelSpec priority(PriorityCapableChannelMessageStore me
 
 	public static PriorityChannelSpec priority(String id,
 			PriorityCapableChannelMessageStore messageGroupStore, Object groupId) {
+
 		return priority(messageGroupStore, groupId).id(id);
 	}
 
-	public static <S extends PublishSubscribeChannelSpec<S>> PublishSubscribeChannelSpec<S> publishSubscribe() {
+	public static PublishSubscribeChannelSpec<?> publishSubscribe() {
 		return new PublishSubscribeChannelSpec<>();
 	}
 
-	public static <S extends PublishSubscribeChannelSpec<S>> PublishSubscribeChannelSpec<S> publishSubscribe(
-			String id) {
-		return MessageChannels.<S>publishSubscribe().id(id);
+	public static PublishSubscribeChannelSpec<?> publishSubscribe(String id) {
+		return MessageChannels.publishSubscribe().id(id);
 	}
 
-	public static <S extends PublishSubscribeChannelSpec<S>> PublishSubscribeChannelSpec<S> publishSubscribe(
-			Executor executor) {
+	public static PublishSubscribeChannelSpec<?> publishSubscribe(Executor executor) {
 		return new PublishSubscribeChannelSpec<>(executor);
 	}
 
-	public static <S extends PublishSubscribeChannelSpec<S>> PublishSubscribeChannelSpec<S> publishSubscribe(String id,
-			Executor executor) {
-		return MessageChannels.<S>publishSubscribe(executor).id(id);
+	public static PublishSubscribeChannelSpec<?> publishSubscribe(String id, Executor executor) {
+		return MessageChannels.publishSubscribe(executor).id(id);
 	}
 
 	public static FluxMessageChannelSpec flux() {

spring-integration-core/src/test/kotlin/org/springframework/integration/dsl/routers/RouterDslTests.kt

@@ -28,6 +28,7 @@ import org.springframework.context.annotation.Configuration
 import org.springframework.integration.channel.QueueChannel
 import org.springframework.integration.config.EnableIntegration
 import org.springframework.integration.dsl.IntegrationFlow
+import org.springframework.integration.dsl.MessageChannels
 import org.springframework.integration.support.MessageBuilder
 import org.springframework.messaging.MessageChannel
 import org.springframework.messaging.PollableChannel
@@ -133,6 +134,12 @@ class RouterDslTests {
                 IntegrationFlow { flow ->
                     flow.handle<Any> { _, _ -> "even" }
                 }
+
+        @Bean
+        fun publishSubscribe() =
+                MessageChannels.publishSubscribe()
+                        .ignoreFailures(true)
+                        .applySequence(false)
     }
 
 }