[Backend] Deleted Attachments Returning in Confluence Search Results

Summary

Attachments which have been deleted from a Confluence Page are still searchable after a Content Index is performed

Environment

• Confluence Cloud version 6.0.0-OD-2016.07.2
• Confluence server version 5.9.x and above

Steps to Reproduce

1. Add an attachment to a Confluence Page (does not need to be embedded on the page itself)
2. Search for the Attachment using the Filename of the Attachment; it should display in the Search Results
3. Delete the Attachment
4. Search again for the Attachment; should not display in the Search Results
5. Perform a task which triggers a Content Index (Move Pages, Create Space, etc) or as SysAdmin, manually trigger a Content Re-Index

Expected Results

Deleted attachment does not return in search results

Actual Results

• Deleted Attachment is shown in search results however when clicked displays a file not found error:
  
• In some versions, deleted Attachments are able to be viewed like normal attachment
• The attachment also reappeared in the Space Attachment list by going to Space Tools > Content Tools > Attachments

Database shows that the Attachment has been deleted:

confluence=> select contentid, contenttype, title, content_status from content where title like '%ExampleAttachment%';
 contentid | contenttype |          title          | content_status
-----------+-------------+-------------------------+----------------
   5046279 | ATTACHMENT  | 1.ExampleAttachment.png | deleted
   5046280 | ATTACHMENT  | 2.ExampleAttachment.png | deleted
(2 rows)

Notes

1. Rebuilding Cache does not seem to correct the issue
2. Reindexing from scratch does not seem to correct the issue either

Workaround

1. Delete the attachment from the trash by going to Space Tool > Content Tools > Trash > choose the deleted attachments > Delete
2. Purge the trash by going to Space Tool > Content Tools > Trash > purge