From 77d83bc6acbcef74adb9099ebb6dde809e146125 Mon Sep 17 00:00:00 2001
From: Michael Pfaff <michael@pfaff.dev>
Date: Sun, 11 Aug 2024 00:25:30 -0400
Subject: [PATCH] Add missing null check of original model in
 BufferedMethodBuilder

---
 .../jdk/internal/classfile/impl/AbstractBuilder.java   |  9 +++++++++
 .../internal/classfile/impl/AbstractDirectBuilder.java |  7 +++----
 .../internal/classfile/impl/BufferedMethodBuilder.java | 10 +++++++---
 3 files changed, 19 insertions(+), 7 deletions(-)
 create mode 100644 src/java.base/share/classes/jdk/internal/classfile/impl/AbstractBuilder.java

diff --git a/src/java.base/share/classes/jdk/internal/classfile/impl/AbstractBuilder.java b/src/java.base/share/classes/jdk/internal/classfile/impl/AbstractBuilder.java
new file mode 100644
index 0000000000000..2f3ee67c36a36
--- /dev/null
+++ b/src/java.base/share/classes/jdk/internal/classfile/impl/AbstractBuilder.java
@@ -0,0 +1,9 @@
+package jdk.internal.classfile.impl;
+
+public abstract class AbstractBuilder<M> {
+    protected final M original;
+
+    protected AbstractBuilder(M original) {
+        this.original = original;
+    }
+}
diff --git a/src/java.base/share/classes/jdk/internal/classfile/impl/AbstractDirectBuilder.java b/src/java.base/share/classes/jdk/internal/classfile/impl/AbstractDirectBuilder.java
index 8d00d0609964e..e61e9df23ea40 100644
--- a/src/java.base/share/classes/jdk/internal/classfile/impl/AbstractDirectBuilder.java
+++ b/src/java.base/share/classes/jdk/internal/classfile/impl/AbstractDirectBuilder.java
@@ -27,16 +27,15 @@
 import java.lang.classfile.Attribute;
 import java.lang.classfile.constantpool.ConstantPool;
 
-public class AbstractDirectBuilder<M> {
+public abstract class AbstractDirectBuilder<M> extends AbstractBuilder<M> {
     protected final SplitConstantPool constantPool;
     protected final ClassFileImpl context;
     protected final AttributeHolder attributes = new AttributeHolder();
-    protected final M original;
 
-    public AbstractDirectBuilder(SplitConstantPool constantPool, ClassFileImpl context, M original) {
+    protected AbstractDirectBuilder(SplitConstantPool constantPool, ClassFileImpl context, M original) {
+        super(original);
         this.constantPool = constantPool;
         this.context = context;
-        this.original = original;
     }
 
     public SplitConstantPool constantPool() {
diff --git a/src/java.base/share/classes/jdk/internal/classfile/impl/BufferedMethodBuilder.java b/src/java.base/share/classes/jdk/internal/classfile/impl/BufferedMethodBuilder.java
index 7bf76f7c7a21c..b66c47cce55f3 100644
--- a/src/java.base/share/classes/jdk/internal/classfile/impl/BufferedMethodBuilder.java
+++ b/src/java.base/share/classes/jdk/internal/classfile/impl/BufferedMethodBuilder.java
@@ -46,6 +46,7 @@
 import java.lang.classfile.constantpool.Utf8Entry;
 
 public final class BufferedMethodBuilder
+        extends AbstractBuilder<MethodModel>
         implements TerminalMethodBuilder {
     private final List<MethodElement> elements;
     private final SplitConstantPool constantPool;
@@ -53,7 +54,6 @@ public final class BufferedMethodBuilder
     private final Utf8Entry name;
     private final Utf8Entry desc;
     private AccessFlags flags;
-    private final MethodModel original;
     private int[] parameterSlots;
     @Stable
     MethodTypeDesc mDesc;
@@ -64,13 +64,13 @@ public BufferedMethodBuilder(SplitConstantPool constantPool,
                                  Utf8Entry typeInfo,
                                  int flags,
                                  MethodModel original) {
+        super(original);
         this.elements = new ArrayList<>();
         this.constantPool = constantPool;
         this.context = context;
         this.name = nameInfo;
         this.desc = typeInfo;
         this.flags = new AccessFlagsImpl(AccessFlag.Location.METHOD, flags);
-        this.original = original;
     }
 
     @Override
@@ -106,7 +106,11 @@ public Utf8Entry methodType() {
     @Override
     public MethodTypeDesc methodTypeSymbol() {
         if (mDesc == null) {
-            mDesc = original.methodTypeSymbol();
+            if (original != null) {
+                mDesc = original.methodTypeSymbol();
+            } else {
+                mDesc = MethodTypeDesc.ofDescriptor(methodType().stringValue());
+            }
         }
         return mDesc;
     }