undefect. CWE-407 — 63 sites patched across 27 ecosystems

Authors: russell@unturf.com · brackishbert@gmail.com · foxhop.net · TimeHexOn.com Patches, unit tests, benchmarks, whitepaper, and outreach briefs. Public domain — no copyright claimed. Use freely.
2026-03-26 17:11:57 -04:00 · 2026-03-26 17:11:57 -04:00 · 0a580b313d
commit 0a580b313d
70422 changed files with 17213626 additions and 0 deletions
--- a/test/jdk/java/util/Collections/EmptyCollectionSerialization.java
+++ b/test/jdk/java/util/Collections/EmptyCollectionSerialization.java
@ -0,0 +1,108 @@
+/*
+ * Copyright (c) 2002, 2013, 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     4684279 7129185
+ * @summary Empty utility collections should be singletons
+ * @author  Josh Bloch
+ * @run testng EmptyCollectionSerialization
+ */
+
+import org.testng.annotations.DataProvider;
+import org.testng.annotations.Test;
+
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
+import java.io.InputStream;
+import java.io.ObjectInputStream;
+import java.io.ObjectOutputStream;
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.Iterator;
+import java.util.function.Supplier;
+
+import static org.testng.Assert.assertSame;
+import static org.testng.Assert.fail;
+
+public class EmptyCollectionSerialization {
+    private static Object patheticDeepCopy(Object o) throws Exception {
+        // Serialize
+        ByteArrayOutputStream bos = new ByteArrayOutputStream();
+        ObjectOutputStream oos = new ObjectOutputStream(bos);
+        oos.writeObject(o);
+        byte[] serializedForm = bos.toByteArray();
+
+        // Deserialize
+        InputStream is = new ByteArrayInputStream(serializedForm);
+        ObjectInputStream ois = new ObjectInputStream(is);
+        return ois.readObject();
+    }
+
+    @Test(dataProvider="SerializableSingletons")
+    public static void serializableSingletons(String description, Supplier<Object> o) {
+        try {
+            Object singleton = o.get();
+            assertSame(o.get(), singleton, description + ": broken Supplier not returning singleton");
+            Object copy = patheticDeepCopy(singleton);
+            assertSame(copy, singleton, description + ": " +
+                copy.getClass().getName() + "@" + Integer.toHexString(System.identityHashCode(copy)) +
+                " is not the singleton " +
+                singleton.getClass().getName() + "@" + Integer.toHexString(System.identityHashCode(singleton)));
+        } catch (Exception all) {
+            fail(description + ": Unexpected Exception", all);
+        }
+    }
+
+    @DataProvider(name = "SerializableSingletons", parallel = true)
+    public static Iterator<Object[]> navigableMapProvider() {
+        return makeSingletons().iterator();
+    }
+
+    public static Collection<Object[]> makeSingletons() {
+        Object[][] params = {
+            {"Collections.EMPTY_LIST",
+             (Supplier) () -> Collections.EMPTY_LIST},
+            {"Collections.EMPTY_MAP",
+             (Supplier) () -> Collections.EMPTY_MAP},
+            {"Collections.EMPTY_SET",
+             (Supplier) () -> Collections.EMPTY_SET},
+            {"Collections.emptyList()",
+             (Supplier) () -> Collections.emptyList()},
+            {"Collections.emptyMap()",
+             (Supplier) () -> Collections.emptyMap()},
+            {"Collections.emptySet()",
+             (Supplier) () -> Collections.emptySet()},
+            {"Collections.emptySortedSet()",
+             (Supplier) () -> Collections.emptySortedSet()},
+            {"Collections.emptySortedMap()",
+             (Supplier) () -> Collections.emptySortedMap()},
+            {"Collections.emptyNavigableSet()",
+             (Supplier) () -> Collections.emptyNavigableSet()},
+            {"Collections.emptyNavigableMap()",
+             (Supplier) () -> Collections.emptyNavigableMap()},
+        };
+        return Arrays.asList(params);
+    }
+}