From bcc21b1c041436ab61479da386fede5a8cf68cae Mon Sep 17 00:00:00 2001
From: Rob Bygrave <robin.bygrave@gmail.com>
Date: Thu, 1 Sep 2022 22:45:17 +1200
Subject: [PATCH] #2818 - Fix Concurrent modification of listenerNotify
 TransactionEvent list

The issue fixed here is that SavepointTransaction was effectively using the
TransactionEvent of the underlying 'parent' transaction. The fix is for
SavepointTransaction to have its own TransactionEvent.
---
 .../server/transaction/SavepointTransaction.java       | 10 ++++++++++
 .../tests/transaction/TestNestedSubTransaction.java    |  7 +++++++
 2 files changed, 17 insertions(+)

diff --git a/ebean-core/src/main/java/io/ebeaninternal/server/transaction/SavepointTransaction.java b/ebean-core/src/main/java/io/ebeaninternal/server/transaction/SavepointTransaction.java
index aa4bc978e..8dfcd3b37 100644
--- a/ebean-core/src/main/java/io/ebeaninternal/server/transaction/SavepointTransaction.java
+++ b/ebean-core/src/main/java/io/ebeaninternal/server/transaction/SavepointTransaction.java
@@ -2,6 +2,7 @@ package io.ebeaninternal.server.transaction;
 
 import io.ebeaninternal.api.SpiTransaction;
 import io.ebeaninternal.api.SpiTransactionProxy;
+import io.ebeaninternal.api.TransactionEvent;
 import io.ebeaninternal.server.util.Str;
 
 import javax.persistence.PersistenceException;
@@ -25,6 +26,7 @@ final class SavepointTransaction extends SpiTransactionProxy {
 
   private boolean rollbackOnly;
   private int state;
+  private TransactionEvent event;
 
   SavepointTransaction(SpiTransaction transaction, TransactionManager manager) throws SQLException {
     this.manager = manager;
@@ -40,6 +42,14 @@ final class SavepointTransaction extends SpiTransactionProxy {
     this.logPrefix = transaction.getLogPrefix() + spPrefix;
   }
 
+  @Override
+  public TransactionEvent getEvent() {
+    if (event == null) {
+      event = new TransactionEvent();
+    }
+    return event;
+  }
+
   @Override
   public String getLogPrefix() {
     return logPrefix;
diff --git a/ebean-test/src/test/java/org/tests/transaction/TestNestedSubTransaction.java b/ebean-test/src/test/java/org/tests/transaction/TestNestedSubTransaction.java
index e8f32eced..86161b8aa 100644
--- a/ebean-test/src/test/java/org/tests/transaction/TestNestedSubTransaction.java
+++ b/ebean-test/src/test/java/org/tests/transaction/TestNestedSubTransaction.java
@@ -4,6 +4,8 @@ import io.ebean.*;
 import io.ebean.xtest.BaseTestCase;
 import io.ebean.xtest.IgnorePlatform;
 import io.ebean.annotation.Platform;
+import io.ebeaninternal.api.SpiTransaction;
+import io.ebeaninternal.api.TransactionEvent;
 import org.junit.jupiter.api.Test;
 import org.tests.model.basic.EBasic;
 
@@ -75,10 +77,15 @@ public class TestNestedSubTransaction extends BaseTestCase {
 
       server.save(bean);
 
+      TransactionEvent event0 = ((SpiTransaction) txn0).getEvent();
+
       try (Transaction txn1 = server.beginTransaction()) {
         bean.setName("updateNested");
         server.save(bean);
 
+        TransactionEvent event1 = ((SpiTransaction) txn1).getEvent();
+        assertThat(event1).isNotSameAs(event0);
+
         try (Transaction txn2 = server.beginTransaction()) {
           bean.setName("barney");
           DB.save(bean);