When I merge pages (at https://en.wikipedia.org/w/index.php?title=Special:MergeHistory), and then look at the user contributions of the user who "created" the target page, te "diff" isn't a link, even though it should be for non-first edits - see https://en.wikipedia.org/w/index.php?title=Special:Contributions&offset=20110203113618&limit=50&tagfilter=&contribs=user&target=Cydebot&namespace=14&deletedOnly=1, where thgere are a whole lot of these pages.