1824740 - DataTransfer.setData is adding the data in the wrong order when the format already exists

Status: NEW

(Core :: DOM: Copy & Paste and Drag & Drop, defect)

Description

[Neil Deakin]

Attachment: dragtypes-orderbug.html

To reproduce: Open the testcase, select the 'Drag Me' text and drag it.

The testcase calls setData three times:

event.dataTransfer.setData('text/plain', 'There is some text here.');
event.dataTransfer.setData('text/horse', 'There is some horse here.');
event.dataTransfer.setData('text/plain', 'There is some elephant here.');

The last line adds data of the same format that already exists. The spec says that setData should remove the existing item first and then add the new data. This is what other browsers do. Firefox however replaces the item in the same position instead.