OK, that was weird... All I did for testing was follow // This section should be uncommented if 8026517 is fixed.
but ... 8026517 is marked fixed! So switching to ArrayDeque accidentally fixed 8026517 for real?! 8198810: URLClassLoader does not specify behavior when URL array contains null http://cr.openjdk.java.net/~martin/webrevs/jdk/URLClassLoader-NPE/ https://bugs.openjdk.java.net/browse/JDK-8198810