If the number of search results is an integer multiple of the number of results displayed on one page (e.g., a search for "portend" in the English Wikipedia currently yields 200 results, a multiple of 20, 50 and 100), the last page of results contains a link to the next page of results; clicking on this leads to a page that says "There were no results matching the query". (By contrast, if the number of results isn't a multiple of the number per page, the last, partial page still has the text for the next page link, but it's not a link.)
P.S.: I selected version "1.16-svn" because that was the closest to 'wgVersion = "1.16alpha-wmf"' specified in the HTML source of the search results page. Since this is probably the only way for a lot of people to find out which version they're reporting about, the versions running on the major Wikipedias should preferably be options in the version list (or it should be more obvious which version to choose based on that information).