AWS S3: In certain scenarios purging an attachment will delete the versions of another

Issue Summary

This is reproducible on Data Center: yes

Steps to Reproduce

1. Upload an attachment via Confluence
2. Determine the v4 S3 path of the attachment in the configured S3 bucket using the script defined here
3. Create a new folder in the this path thats retains the original attachment ID as its prefix but includes an additional digit as its suffix.
   1. For example, the v4 path in S3 for the original attachment (ID 950279) would be confluence/attachments/v4/21/128/950279. In this case create another folder in the same path called 9502791 i.e. confluence/attachments/v4/21/128/9502791 See screenshot for detail
      
4. Upload a new attachment into the new S3 path i.e. confluence/attachments/v4/21/128/9502791/random_attachment.jpg
5. Now, from Confluence, perform a full purge of the original attachment (ID 950279) by selecting  Delete > Space Tools > Content Tools > Trash > Purge (the deleted attachment)
6. Doing this not only results in 950279 being purged including its versions but it also results in confluence/attachments/v4/21/128/9502791/random_attachment.jpg being deleted 

Expected Results

Purging a particular attachment should not impact any other attachments and their versions.

Actual Results

An attachment that is stored in the same path as another attachment, and that shares the same attachment ID as its prefix will have its versions deleted when that other attachment is purged, where:

• purging the attachment: confluence/attachments/v4/21/128/950279
• will also delete this attachments version(s) confluence/attachments/v4/21/128/9502791/random_attachment.jpg

Workaround

Currently not known.