INT-1858 removed requirememt for top-level gateway to have an ID attribute

spring-integration-core/src/main/java/org/springframework/integration/config/xml/GatewayParser.java

@@ -53,6 +53,10 @@ public class GatewayParser extends AbstractSimpleBeanDefinitionParser {
 	protected String getBeanClassName(Element element) {
 		return IntegrationNamespaceUtils.BASE_PACKAGE + ".gateway.GatewayProxyFactoryBean";
 	}
+	
+	protected boolean shouldGenerateIdAsFallback() {
+		return true;
+	}
 
 	@Override
 	protected boolean isEligibleAttribute(String attributeName) {

spring-integration-core/src/test/java/org/springframework/integration/config/xml/gatewayParserTests.xml

@@ -29,5 +29,8 @@
 	         default-request-channel="requestChannel"
 	         default-reply-channel="replyChannel"
 	         default-reply-timeout="5000"/>
+	         
+	<!-- no assertions for this. The fact that this config does not result in error is sufficient -->
+	<gateway default-request-channel="nullChannel"/>
 
 </beans:beans>