I hope I am doing this right, it is my first feature request:
When multiple people try to save a page, the MediaWiki software creates an "edit conflict" window to warn them that the page has just been changed.
I would like a similar behavior for protections. For example, this page on Wikipedia was protected four times in a row with the same length: http://en.wikipedia.org/w/index.php?title=Special:Log&page=User_talk%3AEast718
So I think the software should output a warning if 1.) the page has been protected while one was on the protection page or 2.) one chose the same protection level that already is applied (e.g. if it's already indef protected, selecting indef protection should generate a warning).