8215916: The failure reason of an optional JAAS LoginModule is not logged

src/java.base/share/classes/javax/security/auth/login/LoginContext.java

@@ -875,9 +875,10 @@ private void invoke(String methodName) throws LoginException {
                         firstRequiredError = le;
 
                 } else {
-
-                    if (debug != null)
+                    if (debug != null) {
                         debug.println(name + " " + methodName + " OPTIONAL failure");
+                        le.printStackTrace();
+                    }
 
                     // mark down that an OPTIONAL module failed
                     if (firstError == null)

test/jdk/javax/security/auth/login/LoginContext/OptionalJaas/UnixNTPlatform.java

@@ -0,0 +1,77 @@
+/*
+ * Copyright (c) 2022, Red Hat, Inc.
+ * 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 8215916
+ * @summary This test case attempts to verify whether call stack trace is
+ * printed when JAAS optional login fails when debug is true.
+ * @run main/othervm -Djava.security.debug=logincontext UnixNTPlatform
+ */
+import javax.security.auth.login.LoginContext;
+import javax.security.auth.login.LoginException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.io.ByteArrayOutputStream;
+import java.io.PrintStream;
+
+public class UnixNTPlatform {
+
+    public static void main(String[] args) throws Exception {
+        System.out.println("Testing cross-platform");
+
+        String config = """
+                        hello {
+                        com.sun.security.auth.module.UnixLoginModule optional debug=true;
+                        com.sun.security.auth.module.NTLoginModule optional debug=true;
+                        };
+                        """;
+
+        System.out.println("config is : \n"+config);
+        Files.writeString(Path.of("cross-platform"), config.toString());
+
+        System.setProperty("java.security.auth.login.config", "cross-platform");
+
+        ByteArrayOutputStream stream = new ByteArrayOutputStream();
+        PrintStream ps = System.err;
+        System.setErr(new PrintStream(new PrintStream(stream)));
+
+        try {
+            LoginContext lc = new LoginContext("hello");
+            lc.login();
+            System.out.println(lc.getSubject());
+            lc.logout();
+        } catch (LoginException e) {
+            System.out.println("Retrieving exception information");
+        } finally {
+            System.setErr(ps);
+        }
+
+        byte[] byes = stream.toByteArray();
+        String s = new String(byes);
+        System.out.printf("-- call stack is -- %n%s%n", s);
+        if (!s.contains("Failed in attempt to import the underlying")) {
+           throw new RuntimeException();
+        }
+    }
+}