Lead to a fatal in WMF production, see I40c1412d
Change-Id: I39e05210e77f3dc0a1fcd995201a9c1ec9bc99f3
$isWatch: (No longer used)
$section: (No longer used)
$flags: Flags passed to WikiPage::doEditContent()
-$revision: New Revision of the article
+$revision: New Revision of the article (can be null for edits that change nothing)
$status: Status object about to be returned by doEditContent()
$baseRevId: the rev ID (or false) this edit was based on