From 4222c5b8ce9df6403a5abadd6a088b4d7214f4e6 Mon Sep 17 00:00:00 2001
From: Andy Wilkinson <awilkinson@pivotal.io>
Date: Wed, 12 Jun 2019 12:53:16 +0100
Subject: [PATCH] Prevent URLResource and JarURLConnection from leaking an
 InputStream

Fixes gh-17121
---
 .../boot/web/embedded/undertow/JarResourceManager.java        | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/spring-boot-project/spring-boot/src/main/java/org/springframework/boot/web/embedded/undertow/JarResourceManager.java b/spring-boot-project/spring-boot/src/main/java/org/springframework/boot/web/embedded/undertow/JarResourceManager.java
index 3f7ad6909ba..d118d99412b 100644
--- a/spring-boot-project/spring-boot/src/main/java/org/springframework/boot/web/embedded/undertow/JarResourceManager.java
+++ b/spring-boot-project/spring-boot/src/main/java/org/springframework/boot/web/embedded/undertow/JarResourceManager.java
@@ -26,6 +26,8 @@ import io.undertow.server.handlers.resource.ResourceChangeListener;
 import io.undertow.server.handlers.resource.ResourceManager;
 import io.undertow.server.handlers.resource.URLResource;
 
+import org.springframework.util.StringUtils;
+
 /**
  * {@link ResourceManager} for JAR resources.
  *
@@ -48,7 +50,7 @@ class JarResourceManager implements ResourceManager {
 	public Resource getResource(String path) throws IOException {
 		URL url = new URL("jar:file:" + this.jarPath + "!" + (path.startsWith("/") ? path : "/" + path));
 		URLResource resource = new URLResource(url, path);
-		if (resource.getContentLength() < 0) {
+		if (StringUtils.hasText(path) && !"/".equals(path) && resource.getContentLength() < 0) {
 			return null;
 		}
 		return resource;