Issue Summary

The validation step of the CSV issue-import process should at least warn and explain the consequences (if not error out) of having a subtask assigned to an epic in the CSV file. Currently, nothing gets raised at the validation stage. On some versions of Jira, we silently continue through the actual import without any errors (<8.10, >=8.13.7). On others, we blow up (~8.11-8.13.6).
Neither of these outcomes is desirable. I want Jira to warn me at the validation stage if there are instances of subtasks being assigned to epics, and the warning should state that Jira will ignore these assignments and have the new subtasks inherit from the parent task. Then, the actual import process should do exactly that.

Steps to Reproduce

Same as in JRASERVER-71995 or JRASERVER-71880.

Expected Results

The validator raises a warning when a subtask is assigned to the same Epic as its parent. Technically, subtasks cannot have their own epic assignments; they inherit them.

When a subtask is assigned to a different epic than its parent, either:

• A stronger warning is raised, and the user is informed that the affected subtask will not have the intended epic assignment.
• an error is raised and the CSV data must be fixed before the import operation can be performed.

Actual Results

The validation passes with no problems, and the import is allowed to continue.

Workaround

Currently there is no known workaround for this behavior. A workaround will be added here when available