When JIRA Agile updates sub-task's Sprint field, no event is sent inside JIRA

If a Story that has sub-tasks is assigned to another Sprint, JIRA Agile changes Sprint field for the sub-tasks too. However, no event is sent for the sub-tasks in the JIRA event system - neither ISSUE_UPDATED, nor GENERIC_EVENT.

This presents a problem for other plugins like Structure, which listen for the events and react to them. In particular, Structure's synchronizers are not able to maintain correct representation of the Sprints if its filter synchronizer does not check the updated issue.

Reproduction sequence:
1. Create a story in the backlog
2. Create a sub-task for that story
3. Assign story to Sprint 1, observe: sub-task is also assigned to Sprint 1

Expected: internal event is sent for the story and for the sub-task (issueUpdated or issueGenericEvent)
Observed: the event is sent only for the story

The observation can be done by registering an IssueEventListener. You can also use Structure to verify that the event is not sent:

A. Install Structure
B. Open Structure | Manage Structure, click "Settings" for the structure in the "Sync With..." column
C. Install "Filter" synchronizer with a JQL condition sprint = "Sprint 1"
D. Resync the synchronizer and open the structure to see all issues from Sprint 1
E. Continue with the reproduction sequence 1-3 above.

Observe: only the Story is added to the structure, but not the sub-task