Attachement empty after page rollback

Step to reproduce:

• Create a clean XWiki instance on 17.10.13
• Go on the macro doc page at the URL: http://localhost:8080/xwiki/bin/view/Help/Macros/
• Go on attachement and see the attachement size
• Go on History and rollback to version "Help Application 17.10.13"
• Go back to the attachement page

Expected:

All attachement have some content
The diff between the page provided by the extension and the current version is empty

Currently

All attachement are empty
The size of each attachement changed from some size to 0.