Fix boundary event iterator desynchronization in ContinueProcessOperation

modules/flowable-engine/src/main/java/org/flowable/engine/impl/agenda/ContinueProcessOperation.java

@@ -15,6 +15,7 @@
 import java.util.ArrayList;
 import java.util.Iterator;
 import java.util.List;
+import java.util.stream.Collectors;
 
 import org.flowable.bpmn.model.Activity;
 import org.flowable.bpmn.model.BoundaryEvent;
@@ -360,11 +361,8 @@ protected List<ExecutionEntity> createBoundaryEvents(List<BoundaryEvent> boundar
         // The parent execution becomes a scope, and a child execution is created for each of the boundary events
         for (BoundaryEvent boundaryEvent : boundaryEvents) {
 
-            if (!(boundaryEvent.getBehavior() instanceof BoundaryEventRegistryEventActivityBehavior)) {
-                if (CollectionUtil.isEmpty(boundaryEvent.getEventDefinitions())
-                        || (boundaryEvent.getEventDefinitions().get(0) instanceof CompensateEventDefinition)) {
-                    continue;
-                }
+            if (!isExecutableBoundaryEvent(boundaryEvent)) {
+                continue;
             }
 
             // A Child execution of the current execution is created to represent the boundary event being active
@@ -389,6 +387,7 @@ protected List<ExecutionEntity> createBoundaryEvents(List<BoundaryEvent> boundar
 
     protected void executeBoundaryEvents(List<BoundaryEvent> boundaryEvents, List<ExecutionEntity> boundaryEventExecutions) {
         if (!CollectionUtil.isEmpty(boundaryEventExecutions)) {
+            boundaryEvents = boundaryEvents.stream().filter(this::isExecutableBoundaryEvent).collect(Collectors.toList());
             Iterator<BoundaryEvent> boundaryEventsIterator = boundaryEvents.iterator();
             Iterator<ExecutionEntity> boundaryEventExecutionsIterator = boundaryEventExecutions.iterator();
 
@@ -401,4 +400,14 @@ protected void executeBoundaryEvents(List<BoundaryEvent> boundaryEvents, List<Ex
             }
         }
     }
+
+    private boolean isExecutableBoundaryEvent(BoundaryEvent boundaryEvent) {
+        if (!(boundaryEvent.getBehavior() instanceof BoundaryEventRegistryEventActivityBehavior)) {
+            if (CollectionUtil.isEmpty(boundaryEvent.getEventDefinitions())
+                    || (boundaryEvent.getEventDefinitions().get(0) instanceof CompensateEventDefinition)) {
+                return false;
+            }
+        }
+        return true;
+    }
 }

modules/flowable-engine/src/test/java/org/flowable/engine/test/bpmn/event/compensate/CompensateEventTest.java

@@ -337,4 +337,11 @@ public void testCompensateNestedSubprocess() {
 
     }
 
+    @Test
+    @Deployment(resources = { "org/flowable/engine/test/bpmn/event/compensate/CompensateEventTest.testCompensationTimerEventBoundary.bpmn20.xml" })
+    public void testCompensationTimerEventBoundary() {
+        ProcessInstance processInstance = runtimeService.startProcessInstanceByKey("compensationTimerEventBoundary");
+        assertThat(processInstance).isNotNull();
+    }
+
 }

modules/flowable-engine/src/test/resources/org/flowable/engine/test/bpmn/event/compensate/CompensateEventTest.testCompensationTimerEventBoundary.bpmn20.xml

@@ -0,0 +1,31 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<definitions xmlns="http://www.omg.org/spec/BPMN/20100524/MODEL" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:flowable="http://flowable.org/bpmn" xmlns:bpmndi="http://www.omg.org/spec/BPMN/20100524/DI" xmlns:omgdc="http://www.omg.org/spec/DD/20100524/DC" xmlns:omgdi="http://www.omg.org/spec/DD/20100524/DI" typeLanguage="http://www.w3.org/2001/XMLSchema" expressionLanguage="http://www.w3.org/1999/XPath" targetNamespace="http://www.flowable.org/processdef" exporter="Flowable Open Source Modeler">
+  <process id="compensationTimerEventBoundary" name="compensationTimerEventBoundary" isExecutable="true">
+    <startEvent id="startEvent1" flowable:formFieldValidation="true"></startEvent>
+    <sequenceFlow sourceRef="startEvent1" targetRef="first"></sequenceFlow>
+
+    <scriptTask id="first" name="first service task" scriptFormat="groovy">
+      <script><![CDATA[System.out.println('first service task');]]></script>
+    </scriptTask>
+
+    <boundaryEvent id="firstCompensateEvent" attachedToRef="first" cancelActivity="false">
+      <compensateEventDefinition/>
+    </boundaryEvent>
+
+    <scriptTask id="compensateServiceTask" name="compensate service task" scriptFormat="groovy" isForCompensation="true">
+      <script><![CDATA[System.out.println('compensate service task');]]></script>
+    </scriptTask>
+
+    <boundaryEvent id="firstTimerEvent" attachedToRef="first" cancelActivity="false">
+      <timerEventDefinition>
+        <timeDuration>PT5M</timeDuration>
+      </timerEventDefinition>
+    </boundaryEvent>
+    <userTask id="userTask" name="initiator" flowable:assignee="$INITIATOR" flowable:formFieldValidation="true"/>
+
+    <endEvent id="end"/>
+    <sequenceFlow sourceRef="first" targetRef="end"></sequenceFlow>
+    <sequenceFlow sourceRef="firstTimerEvent" targetRef="userTask"></sequenceFlow>
+    <association sourceRef="firstCompensateEvent" targetRef="compensateServiceTask" associationDirection="None"></association>
+  </process>
+</definitions>