RELEASE 2021.1 hotfix patch 13.09

Author: yuriy-glotanov

src/main/java/su/interference/core/EventProcessor.java

@@ -0,0 +1,6 @@
+package su.interference.core;
+
+public interface EventProcessor {
+    boolean process(Object event);
+    boolean delete();
+}

src/main/java/su/interference/core/TransCleanUp.java

@@ -1,7 +1,7 @@
 /**
  The MIT License (MIT)
 
- Copyright (c) 2010-2020 head systems, ltd
+ Copyright (c) 2010-2021 head systems, ltd
 
  Permission is hereby granted, free of charge, to any person obtaining a copy of
  this software and associated documentation files (the "Software"), to deal in
@@ -90,7 +90,8 @@ private void cleanUp() {
                                     //deallocate undo frame
                                     final FrameData ub = Instance.getInstance().getFrameById(tf.getUframeId());
                                     //store frame params as free
-                                    if (!hasfb) {
+                                    //todo undo space may not be not deallocated - check ub for not null
+                                    if (!hasfb && ub != null) {
                                         final FreeFrame fb = new FreeFrame(0, tf.getUframeId(), ub.getSize());
                                         session.persist(fb); //insert
                                         session.delete(ub);