First time restore of a document from "revision history" is not working

Steps to reproduce:-->
1.Open a news document.
2.edit the news document .Change the summary.
3.Publish the changes.
4.A new revision history is created under document.
5.Now click on that revision.
6.Click on the restore button to restore the old revision of the document. i.e before document is edited(in original form )
7.Notice nothing happens & still you see your changes which were made in step2.

Expected:-->Changes should be reverted in the document when the restore button is clicked for a document revision history.

Note:-->1.After first time restore which is not working at this moment.
2.Try one more time & edit the document.This time edit/add some text in description.
3.Publish your changes.
4.Now under document notice two revisions are created for that document.
5.choose the latest revision & click restore button.
6.and this time restore actually works & your changes get reverted.

In step5 .Even if you choose the first revision history.You won't see the original document rather you will see only your latest changes got reverted.

Conclusion.First restore is not working & there is no way that the original document is restored.

Check screenshot for reference.