"Suppress redirect" checkbox on Special:MovePage should not just disappear if creating a redirect is impossible
completed by: Jared Flores
mentors: Bartosz Dziewoński, Kunal Mehta
By default, when a page is moved, a redirect to the new title is created at the old title. Site administrators can override this behavior with a "Suppress redirect" checkbox.
However, when creating a redirect is impossible (the "content model" of a given page does not support redirects), the checkbox currently just disappears, which can be confusing, especially when the wiki has overridden the move message
to indicate that there will be such a checkbox.
A disabled, ticked checkbox should be shown instead.
(You can reproduce this by creating and then trying to move any page ending with ".js" or ".css" in the MediaWiki: namespace on your wiki, e.g. "MediaWiki:Common.css".)