1e0db7de_eters_to_index_php___MediaWiki__Function
[Name] historysubmit [Example] www.mediawiki.org/w/index.php?title=Project:Sandbox&action=historysubmit&diff=456290&oldid=456270 [Function] 
When viewing the difference between revisions, after clicking "compare selected revisions" on the history page. This requires a "diff" and/or "oldid" parameter, otherwise it just shows the page itself.
Manual:Parameters to index.php - MediaWiki