Steps to reproduce
- Open a page for editing, e.g. User talk:Tacsipacsi/sandbox.
- Enter some edit summary.
- Click Show preview or Show changes.
- Look at the preview of the edit summary.
- The edit summary is not italic.
- The edit summary is shown in italic.
- New regression in 1.37.0-wmf.18.
- Tested with Monobook, legacy and new Vector, other skins may be broken as well.
- When fixing this, care should be taken to fix both the traditional, full page reload experience, and the AJAX-based live preview (T41272).