TaskService.getIdentityLinksForTask(taskId)

[maratkalibek]

Describe the bug

TaskService.getIdentityLInksForTask(taskId) is duplicating IdentityLink in results. Looks like same IdentityLink added to list twice.

Expected behavior

TaskService.getIdentityLInksForTask(taskId) should not duplicate IdentityLink in results.

Code

Additional context

https://github.com/flowable/flowable-engine/blob/main/modules/flowable-task-service/src/main/java/org/flowable/task/service/impl/persistence/entity/TaskEntityImpl.java#L247-L270

Here, getCandidates method returns set, but getIdentityLinks returns map. So duplicates are removed for getCandidates method.

[pandaapo]

Can you describe more details? How to reproduce this bug? Which version of flowable? And anything else.

[kendoziyu]

I've had a similar issue too. This problem is easy to reproduce.

Flowable Engine Version
As of the latest 6.7.2-release, this issue has not been resolved

<dependency>
    <groupId>org.flowable</groupId>
    <artifactId>flowable-engine</artifactId>
    <version>6.7.2</version>
</dependency>

How to reproduce
Just follow the Getting Started.

Here is my sample project zip package：
flowable-example.zip

Set the breakpoint to org.flowable.engine.impl.util.IdentityLinkUtil as shown

Then you see the problem

[arthware]

Quickly checked this: This is a runtime behavior inconsistency on the TaskEntity, which seems to happen only during process execution. Problem is gone, when the task is loaded again, or the taskService.getIdentityLinksForTask method is used.

Root cause of the problem is, that taskEntityImpl#getIdentityLinks is not a simple getter like expected, but it initializes identity links too.

The identityLink gets initially created (and persisted) in

flowable-engine/modules/flowable-engine/src/main/java/org/flowable/engine/impl/bpmn/behavior/UserTaskActivityBehavior.java

Line 375 in 97277a6

List<IdentityLinkEntity> identityLinkEntities = processEngineConfiguration.getIdentityLinkServiceConfiguration()

And then twice here (once because the unexpected side-effect in taskEntity.getIdentityLinks()):

flowable-engine/modules/flowable-cmmn-engine/src/main/java/org/flowable/cmmn/engine/impl/util/IdentityLinkUtil.java

Line 90 in 982be7e

taskEntity.getIdentityLinks().add(identityLinkEntity);

The TaskEntityImpl getter:

flowable-engine/modules/flowable-task-service/src/main/java/org/flowable/task/service/impl/persistence/entity/TaskEntityImpl.java

Lines 261 to 262 in 02b22f8

	if (queryIdentityLinks == null) {
	taskIdentityLinkEntities = getIdentityLinkServiceConfiguration().getIdentityLinkEntityManager().findIdentityLinksByTaskId(id);

In general that is not so nice, because the getter does not even work, when it is called outside of an execution (with a NPE).