/* * Copyright (c) 2019, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ /** * @test * @bug 8234423 * @summary Modifying ArrayList.subList().subList() resets modCount of subList */ import java.util.ArrayList; import java.util.ConcurrentModificationException; public class SubListModCount { public static void main(String[] args) { int failures = 0; var root = new ArrayList(); var subList = root.subList(0, 0); root.add(42); try { subList.size(); failures++; System.out.println("Accessing subList"); } catch (ConcurrentModificationException expected) { } var subSubList = subList.subList(0, 0); try { subSubList.size(); failures++; System.out.println("Accessing subList.subList"); } catch (ConcurrentModificationException expected) { } try { subSubList.add(42); failures++; System.out.println("Modifying subList.subList"); } catch (ConcurrentModificationException expected) { } try { subList.size(); failures++; System.out.println("Accessing subList again"); } catch (ConcurrentModificationException expected) { } if (failures > 0) { throw new AssertionError(failures + " tests failed"); } } }