first fix (must still be cleaned up)

hibernate-envers/src/main/java/org/hibernate/envers/strategy/ValidityAuditStrategy.java

@@ -71,8 +71,39 @@ public class ValidityAuditStrategy implements AuditStrategy {
     @SuppressWarnings({"unchecked"})
     public void performCollectionChange(Session session, AuditConfiguration auditCfg,
                                         PersistentCollectionChangeData persistentCollectionChangeData, Object revision) {
+
+        final boolean lastRevisionCanBeUpdated;
+
+        // TODO clean this up, remove duplicate code
         // Update the end date of the previous row if this operation is expected to have a previous row
-        if (getRevisionType(auditCfg, persistentCollectionChangeData.getData()) != RevisionType.ADD) {
+        if (getRevisionType(auditCfg, persistentCollectionChangeData.getData()) == RevisionType.ADD) {
+            // ADD: special checking is necessary to see if this is really the first insert with the given primary key
+            final QueryBuilder qb = new QueryBuilder(persistentCollectionChangeData.getEntityName(), "e");
+
+            // Adding a parameter for each id component, except the rev number
+            String originalIdPropName = auditCfg.getAuditEntCfg().getOriginalIdPropName();
+            Map<String, Object> originalId = (Map<String, Object>) persistentCollectionChangeData.getData().get(
+                    originalIdPropName);
+            for (Map.Entry<String, Object> originalIdEntry : originalId.entrySet()) {
+                if (!auditCfg.getAuditEntCfg().getRevisionFieldName().equals(originalIdEntry.getKey())) {
+                    qb.getRootParameters().addWhereWithParam(originalIdPropName + "." + originalIdEntry.getKey(),
+                            true, "=", originalIdEntry.getValue());
+                }
+            }
+
+            // e.end_rev is null
+            String revisionEndFieldName = auditCfg.getAuditEntCfg().getRevisionEndFieldName();
+            qb.getRootParameters().addWhere(revisionEndFieldName, true, "is", "null", false);
+
+            // last revision can be updated if the query returned at least one row
+            final List<Object> l = qb.toQuery(session).list();
+            lastRevisionCanBeUpdated = l.size() > 0;
+        } else {
+            // revision type is something else than ADD: last revision can be safely updated
+            lastRevisionCanBeUpdated = true;
+        }
+
+        if (lastRevisionCanBeUpdated) {
             /*
              Constructing a query (there are multiple id fields):
              select e from audited_middle_ent e where e.end_rev is null and e.id1 = :id1 and e.id2 = :id2 ...