Changing a project key then moving an issue with attachments into that newly-changed project causes the attachments on the issue to become unavailable

(This affects JIRA "6.1-OD-9-WN" but that version isn't an available option.)

Steps to reproduce

1. Create two projects, ONE and TWO.
2. Create an issue in each of those two projects, and add attachments to both.
3. Change the project key of ONE to THREE, and notice the attachment on THREE-1 (previously ONE-1) works fine.
4. Move TWO-1 to the newly-renamed project THREE, TWO-1 now becomes THREE-2.
5. The attachment is no longer accessible from THREE-2, and JIRA spits out the following error in the logs:

   /browse/THREE-2 [jira.issue.thumbnail.DefaultThumbnailManager] Error writing to thumbnail file: /data/jirastudio/jira/home/data/attachments/ONE/ONE-2/thumbs/_thumb_10901.png
   java.io.FileNotFoundException: /data/jirastudio/jira/home/data/attachments/ONE/ONE-2/10901 (No such file or directory)