The name of a dropped file over the editing area no longer matches the original name from its source

Steps to reproduce

1. Edit a page with CKEditor (using WYSIWYG and/or in-place editing)
2. Drop a file from the local PC over the editing area (e.g. a text document or an image)
3. Click 'Save & View'

Expected results

In edit, view mode and 'Attachments' tab, the dropped file name matches the file name on the local PC.

Actual results

The file is uploaded with a name consisting of a random set of characters.

The issue could not be reproduced on XWiki 14.10.11 and 15.4.