(In reply to comment #0)

In fact, there's actually a bug in the module related to this: It already
selects <tt>$limit + 1</tt> rows, presumably because it was based on a module
that supported query-continue, so the result currently always contains one more
row than requested.

$this->addOption( 'LIMIT', $limit + 1 );

Indeed. It also doesn't check if said results "fit" into the api resultset

Submitted patch in https://gerrit.wikimedia.org/r/#/c/33702/

• Bug 43943 has been marked as a duplicate of this bug. ***

Merged by Yurik on the 8th.