From c3bf8541d75b1beef767f896e9326ab1241e813e Mon Sep 17 00:00:00 2001
From: Andy Wilkinson <awilkinson@pivotal.io>
Date: Thu, 5 Apr 2018 11:22:35 +0100
Subject: [PATCH] Do not rely on findAvailableTcpPort finding an available port

Closes gh-12779
---
 .../boot/web/embedded/undertow/UndertowServletWebServer.java | 5 ++++-
 .../servlet/server/AbstractServletWebServerFactoryTests.java | 1 -
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/spring-boot-project/spring-boot/src/main/java/org/springframework/boot/web/embedded/undertow/UndertowServletWebServer.java b/spring-boot-project/spring-boot/src/main/java/org/springframework/boot/web/embedded/undertow/UndertowServletWebServer.java
index d86d8bff39f..a39c70035de 100644
--- a/spring-boot-project/spring-boot/src/main/java/org/springframework/boot/web/embedded/undertow/UndertowServletWebServer.java
+++ b/spring-boot-project/spring-boot/src/main/java/org/springframework/boot/web/embedded/undertow/UndertowServletWebServer.java
@@ -266,7 +266,10 @@ public class UndertowServletWebServer implements WebServer {
 		List<Port> ports = new ArrayList<>();
 		for (Object listener : extractListeners()) {
 			try {
-				ports.add(getPortFromListener(listener));
+				Port port = getPortFromListener(listener);
+				if (port.getNumber() != 0) {
+					ports.add(port);
+				}
 			}
 			catch (Exception ex) {
 				// Continue
diff --git a/spring-boot-project/spring-boot/src/test/java/org/springframework/boot/web/servlet/server/AbstractServletWebServerFactoryTests.java b/spring-boot-project/spring-boot/src/test/java/org/springframework/boot/web/servlet/server/AbstractServletWebServerFactoryTests.java
index b17cea6b49a..1daa28f4d5b 100644
--- a/spring-boot-project/spring-boot/src/test/java/org/springframework/boot/web/servlet/server/AbstractServletWebServerFactoryTests.java
+++ b/spring-boot-project/spring-boot/src/test/java/org/springframework/boot/web/servlet/server/AbstractServletWebServerFactoryTests.java
@@ -933,7 +933,6 @@ public abstract class AbstractServletWebServerFactoryTests {
 		doWithBlockedPort((port) -> {
 			try {
 				AbstractServletWebServerFactory factory = getFactory();
-				factory.setPort(SocketUtils.findAvailableTcpPort(40000));
 				addConnector(port, factory);
 				AbstractServletWebServerFactoryTests.this.webServer = factory
 						.getWebServer();