Activiti 5.21.0 发布了，更新如下：

亮点

该版本修复了一些重要的bug，并发布了“安全脚本”功能（针对JavaScript），它允许以安全的方式来执行脚本。

it fixes some cases where the end time was not set for activities in a process definition under certain conditions.

A concurrency bug was discovered when using delegateExpressions together with field injection. Make sure to read the updated documentation section on the use of 'delegateExpression'.

完整更新列表：

Bug

[ACT-2081] - taskCandidateOrAssigned doesn't work with custom GroupEntityManager and UserEntityManager

[ACT-4090] - Boundary timer with fixed number of repeats fires all events at once when attached to nested activity

[ACT-4152] - Task Category not included in query result under MS SQL Server 2012

[ACT-4171] - End time incorrectly set on multi-instance subprocess historic activity

[ACT-4172] - DelegateExpression usage not thread-safe

[ACT-4176] - End time not correctly set on historic activity

[ACT-4185] - NullpointerException occured on referring HistoricVariableUpdate(Serializable Type)

[ACT-4186] - ConcurrentModificationException when event listener removes itself

[ACT-4189] - Process diagram generator: support multiple pools

[ACT-4190] - Job with null due date is never picked up again

[ACT-4181] - fix or queries containing processDefinitionKey clause eliminated adhoc tasks from result set

[ACT-4184] - Fetching historic task with task local and process variables returns current task variables

新特性

[ACT-4166] - Support for multiple signal start events

[ACT-4167] - Support for multiple timer start events

[ACT-4177] - Secure scripting feature

[ACT-4179] - Allow to set business calendar on timer event definition

[ACT-4180] - Process diagram generator: allow to change font for annotations

[ACT-4182] - Query historic variables with a list of execution/task ids

[ACT-4183] - Explorer: omitting the protocol (scheme) in order to preserve the protocol of the current page

[ACT-4187] - Make variable limit configurable when fetching variables

[ACT-4188] - Add support for associations in auto layout and diagram generator

改进

[ACT-2146] - Consider switching around the firing of TaskListeners and ActivitiEventListeners

新特性

[ACT-1963] - Data Object support for Activiti Modeler

[ACT-2073] - Document custom identity link feature in User Guide

[ACT-2074] - add support for custom identity links to Modeler