From 21e0c62f75a2c73d4700e8925696afd3c858e372 Mon Sep 17 00:00:00 2001
From: Adam Sotona <asotona@openjdk.org>
Date: Thu, 23 Nov 2023 12:47:24 +0100
Subject: [PATCH] 8320618: NPE: Cannot invoke
 "java.lang.constant.ClassDesc.isArray()" because "this.sym" is null

---
 .../classfile/impl/StackMapGenerator.java         |  2 +-
 test/jdk/jdk/classfile/StackMapsTest.java         | 15 +++++++++++++--
 2 files changed, 14 insertions(+), 3 deletions(-)

diff --git a/src/java.base/share/classes/jdk/internal/classfile/impl/StackMapGenerator.java b/src/java.base/share/classes/jdk/internal/classfile/impl/StackMapGenerator.java
index 27e68b9ecf9b4..3ae4b25923255 100644
--- a/src/java.base/share/classes/jdk/internal/classfile/impl/StackMapGenerator.java
+++ b/src/java.base/share/classes/jdk/internal/classfile/impl/StackMapGenerator.java
@@ -1394,7 +1394,7 @@ Type toArray() {
         }
 
         Type getComponent() {
-            if (sym.isArray()) {
+            if (isArray()) {
                 var comp = sym.componentType();
                 if (comp.isPrimitive()) {
                     return switch (comp.descriptorString().charAt(0)) {
diff --git a/test/jdk/jdk/classfile/StackMapsTest.java b/test/jdk/jdk/classfile/StackMapsTest.java
index 50b85db5323c5..3950540500144 100644
--- a/test/jdk/jdk/classfile/StackMapsTest.java
+++ b/test/jdk/jdk/classfile/StackMapsTest.java
@@ -24,7 +24,7 @@
 /*
  * @test
  * @summary Testing Classfile stack maps generator.
- * @bug 8305990 8320222
+ * @bug 8305990 8320222 8320618
  * @build testdata.*
  * @run junit StackMapsTest
  */
@@ -43,7 +43,6 @@
 import java.lang.constant.ClassDesc;
 import java.lang.constant.ConstantDescs;
 import java.lang.constant.MethodTypeDesc;
-import java.util.List;
 import java.lang.reflect.AccessFlag;
 
 /**
@@ -237,6 +236,18 @@ void testClassVersions() throws Exception {
                               .verify(null));
     }
 
+    @Test
+    void testInvalidAALOADStack() {
+        Classfile.of().build(ClassDesc.of("Test"), clb
+                -> clb.withMethodBody("test", ConstantDescs.MTD_void, 0, cob
+                        -> cob.bipush(10)
+                              .anewarray(ConstantDescs.CD_Object)
+                              .lconst_1() //long on stack caused NPE, see 8320618
+                              .aaload()
+                              .astore(2)
+                              .return_()));
+    }
+
     private static final FileSystem JRT = FileSystems.getFileSystem(URI.create("jrt:/"));
 
     private static void testTransformedStackMaps(String classPath, Classfile.Option... options) throws Exception {