fix if managed bean is removed and added in same step

ebean-core/src/main/java/io/ebeaninternal/server/persist/SaveManyBeans.java

@@ -307,6 +307,7 @@ final class SaveManyBeans extends SaveManyBase {
     }
 
     transaction.depth(+1);
+    boolean needsFlush = false;
     if (deletions != null && !deletions.isEmpty()) {
       for (Object other : deletions) {
         EntityBean otherDelete = (EntityBean) other;
@@ -315,6 +316,7 @@ final class SaveManyBeans extends SaveManyBase {
         IntersectionRow intRow = many.buildManyToManyMapBean(parentBean, otherDelete, publish);
         SpiSqlUpdate sqlDelete = intRow.createDelete(server, DeleteMode.HARD, many.extraWhere());
         persister.executeOrQueue(sqlDelete, transaction, queue);
+        needsFlush = true;
       }
     }
     if (additions != null && !additions.isEmpty()) {
@@ -334,6 +336,9 @@ final class SaveManyBeans extends SaveManyBase {
             // build a intersection bean for 'insert'
             // They need to be executed very late and would normally go to Queue#2, but we do not have
             // a SpiSqlUpdate for now.
+            if (needsFlush) {
+              transaction.flushBatchOnCascade();
+            }
             if (queue) {
               transaction.depth(+100);
             }

ebean-test/src/test/java/org/tests/model/m2m/TestM2MWithWhere.java

@@ -19,7 +19,7 @@ public class TestM2MWithWhere extends BaseTestCase {
 
   @Test
   public void testModify() throws Exception {
- 
+
     MnyNode node1 = new MnyNode();
     node1.setName("node1");
     node1.setId(111);
@@ -52,6 +52,12 @@ public class TestM2MWithWhere extends BaseTestCase {
     DB.refresh(node2);
     assertThat(node2.getAllRelations()).containsExactlyInAnyOrder(node3);
 
+    node2.getAllRelations().clear();
+    node2.getAllRelations().add(node3);
+    LoggedSql.start();
+    DB.save(node2);
+    LoggedSql.stop().forEach(System.out::println);
+
   }
 
   @Test