Jira Changelog API not capturing sprint changes for subtasks

[DX]

I've done some testing, and I notice that sprint changes, which are normally captured on the changelog API (rest/api/2/issue/ISSUE_KEY/changelog), do not appear for subtasks if they are moved along with a 

To illustrate with an example: Let's say I create ISSUE_1 and ISSUE_2. ISSUE_2 is a subtask of ISSUE_1. At first, they sit in the backlog. I then move ISSUE_1 to SPRINT_A (carrying along ISSUE_2 with it, so now ISSUE_2 is also in SPRINT_A). Then, I kick them to SPRINT_B.

The changelog for ISSUE_1 will rightfully capture all of this movement across sprints, but ISSUE_2's changelog will be devoid of ANY sprint-related entries. 

Why is this the case? This has been a problem for our company, which consumes this API endpoint operating under the assumption that we can piece together an issue's sprint history using the API changelog. I feel this is a fairly reasonable assumption to make, but this behavior on subtasks invalidates it.

[Bill Sheboy]

Hi @DX -- Welcome to the Atlassian Community!

Subtasks are part of a parent issue as its children.  And when you add your ISSUE_1 (e.g., a Story) to a sprint, your ISSUE_2 (e.g. a Subtask) is associated to the parent in order to appear in the sprint's scope...but the fields of ISSUE_2 do not change.

And so when ISSUE_1 changes to a different sprint, there is no changelog entry for ISSUE_2: it never had a value in the sprint field.

Kind regards,
Bill