Unable to create sub-tasks using the + button in the sub-task list when lacking the Edit Issue permission

Steps to reproduce in JIRA 4.4.4:

1. Create an issue
2. Add a sub-task using the More Actions menu
3. You should now see the sub-task list and the + button
4. Make sure your user lacks the Edit Issue permissions
5. Click on the + button
6. You should be redirected to the same page.

This came from an observant user and is not reproducible in JIRA 5.0.6.
I could not find any relevant bugfix but, then again, the Create Issue screen has changed completely in 5.x. Could this be a "collateral fix"?