Attachments with the same filename appear as a single attachment in the Customer Portal

Summary

Attachments with the same file added in the customer portal will appear to the customer as being the same file, the last one added.

Steps to Reproduce

1. Create a new ticket in the Customer Portal
2. Add two attachments to it with the same filename

Expected Results

Each attachment will show in the customer portal, even both having the same name

Actual Results

For the customer, both attachments seems to be the last one added. This bug seems to affect only the customer portal, not JIRA View issue screen, as is possible to see in the images below:

Customer portal:

JIRA View issue screen: