6714834: JarFile.getManifest() leaves an open InputStream as an undoc…

…umented side effect

Reviewed-by: lancea, alanb

src/java.base/share/classes/java/util/jar/JarFile.java

@@ -423,7 +423,9 @@ private Manifest getManifestFromReference() throws IOException {
                     }
                     man = new Manifest(jv, new ByteArrayInputStream(b), getName());
                 } else {
-                    man = new Manifest(super.getInputStream(manEntry), getName());
+                    try (InputStream is = super.getInputStream(manEntry)) {
+                        man = new Manifest(is, getName());
+                    }
                 }
                 manRef = new SoftReference<>(man);
             }