From c0efd49c73c67030f29f426db3f25e95d0387694 Mon Sep 17 00:00:00 2001
From: Rob Bygrave <robin.bygrave@gmail.com>
Date: Thu, 8 Mar 2018 14:12:32 +1300
Subject: [PATCH] #1341 - Cascade persist with JDBC batch and
 BeanPersistAdapter with preUpdate() that invokes lazy loading on persisted
 bean ... results in OptimisticLockException

---
 .../server/persist/BatchedBeanHolder.java     | 15 ++++---
 .../event/BeanPersistControllerTest.java      | 43 +++++++++++++++++++
 2 files changed, 52 insertions(+), 6 deletions(-)

diff --git a/src/main/java/io/ebeaninternal/server/persist/BatchedBeanHolder.java b/src/main/java/io/ebeaninternal/server/persist/BatchedBeanHolder.java
index cfe05cd8c..6c974cc56 100644
--- a/src/main/java/io/ebeaninternal/server/persist/BatchedBeanHolder.java
+++ b/src/main/java/io/ebeaninternal/server/persist/BatchedBeanHolder.java
@@ -85,16 +85,19 @@ public class BatchedBeanHolder {
     // Note updates and deletes can result in many PreparedStatements
     // if their where clauses differ via use of IS NOT NULL.
     if (deletes != null && !deletes.isEmpty()) {
-      control.executeNow(deletes);
-      deletes.clear();
+      ArrayList<PersistRequest> bufferedDeletes = deletes;
+      deletes = new ArrayList<>();
+      control.executeNow(bufferedDeletes);
     }
     if (inserts != null && !inserts.isEmpty()) {
-      control.executeNow(inserts);
-      inserts.clear();
+      ArrayList<PersistRequest> bufferedInserts = inserts;
+      inserts = new ArrayList<>();
+      control.executeNow(bufferedInserts);
     }
     if (updates != null && !updates.isEmpty()) {
-      control.executeNow(updates);
-      updates.clear();
+      ArrayList<PersistRequest> bufferedUpdates = updates;
+      updates = new ArrayList<>();
+      control.executeNow(bufferedUpdates);
     }
     persistedBeans.clear();
   }
diff --git a/src/test/java/io/ebean/event/BeanPersistControllerTest.java b/src/test/java/io/ebean/event/BeanPersistControllerTest.java
index 58d351a1c..e63f77bc3 100644
--- a/src/test/java/io/ebean/event/BeanPersistControllerTest.java
+++ b/src/test/java/io/ebean/event/BeanPersistControllerTest.java
@@ -3,9 +3,12 @@ package io.ebean.event;
 
 import io.ebean.EbeanServer;
 import io.ebean.EbeanServerFactory;
+import io.ebean.Transaction;
 import io.ebean.config.ServerConfig;
 import org.junit.Test;
 import org.tests.model.basic.EBasicVer;
+import org.tests.model.basic.UTDetail;
+import org.tests.model.basic.UTMaster;
 
 import java.util.ArrayList;
 import java.util.Arrays;
@@ -19,6 +22,36 @@ public class BeanPersistControllerTest {
 
   private PersistAdapter stopPersistingAdapter = new PersistAdapter(false);
 
+  @Test
+  public void issue_1341() {
+
+    EbeanServer ebeanServer = getEbeanServer(continuePersistingAdapter);
+
+    UTMaster bean0 = new UTMaster("one0");
+    UTDetail detail0 = new UTDetail("detail0", 12, 23D);
+    bean0.getDetails().add(detail0);
+
+    ebeanServer.save(bean0);
+
+    UTMaster master = ebeanServer.find(UTMaster.class)
+      .setId(bean0.getId())
+      .fetch("details", "name, version")
+      .findOne();
+
+    UTDetail utDetail = master.getDetails().get(0);
+    utDetail.setName("detail0 mod");
+
+    Transaction txn = ebeanServer.beginTransaction();
+    try {
+      txn.setBatchMode(true);
+      ebeanServer.save(master);
+      txn.commit();
+    } finally {
+      txn.end();
+    }
+
+  }
+
   @Test
   public void testInsertUpdateDelete_given_continuePersistingAdapter() {
 
@@ -91,6 +124,8 @@ public class BeanPersistControllerTest {
     config.setRegister(false);
     config.setDefaultServer(false);
     config.getClasses().add(EBasicVer.class);
+    config.getClasses().add(UTMaster.class);
+    config.getClasses().add(UTDetail.class);
 
     config.add(persistAdapter);
 
@@ -130,6 +165,14 @@ public class BeanPersistControllerTest {
     @Override
     public boolean preUpdate(BeanPersistRequest<?> request) {
       methodsCalled.add("preUpdate");
+
+      Object bean = request.getBean();
+      if (bean instanceof UTDetail) {
+        UTDetail detail = (UTDetail)bean;
+        // invoke lazy loading ... which invoke the flush of the jdbc batch
+        detail.setQty(42);
+      }
+
       return continueDefaultPersisting;
     }