8366522: CodeSource.getCodeSigners() throws NPE within empty certs

src/java.base/share/classes/java/security/CodeSource.java

@@ -238,7 +238,12 @@ public final CodeSigner[] getCodeSigners() {
         } else if (certs != null) {
             // Convert the certs to code signers
             signers = convertCertArrayToSignerArray(certs);
-            return signers.clone();
+            if (signers != null) {
+                return signers.clone();
+
+            } else {
+                return null;
+            }
 
         } else {
             return null;

test/jdk/java/security/CodeSource/GetCodeSignersNoCerts.java

@@ -0,0 +1,75 @@
+/*
+ * Copyright Amazon.com Inc. 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.
+ */
+
+import java.net.URL;
+import java.net.URI;
+import java.security.CodeSource;
+import java.security.PublicKey;
+import java.security.cert.Certificate;
+
+/**
+ * @test
+ * @bug 8366522
+ * @summary Verify that NPE is not thrown CodeSource.getCodeSigners() when
+ *          CodeSource is created with empty or null certs argument, or
+ *          there are no X509 certificates in certs
+ */
+public class GetCodeSignersNoCerts {
+    private static final Certificate NON_X509_CERT = new Certificate("") {
+        @Override
+        public byte[] getEncoded() {
+            return new byte[0];
+        }
+
+        @Override
+        public void verify(PublicKey key) {
+        }
+
+        @Override
+        public void verify(PublicKey key, String sigProvider) {
+        }
+
+        @Override
+        public String toString() {
+            return "";
+        }
+
+        @Override
+        public PublicKey getPublicKey() {
+            return null;
+        }
+    };
+
+    public static void main(String[] args) throws Exception {
+        URL location = URI.create("file:///ignored").toURL();
+
+        CodeSource cs = new CodeSource(location, new Certificate[0]);
+        cs.getCodeSigners();
+
+        cs = new CodeSource(location, (Certificate[]) null);
+        cs.getCodeSigners();
+
+        cs = new CodeSource(location, new Certificate[]{NON_X509_CERT});
+        cs.getCodeSigners();
+    }
+}