Auto-scroll doesn't work when doing downward drag-select

When doing a drag-select in a downward direction (such as selecting the text in for example http://www.itworld.com/hardware/426483/ibm-rethinking-decades-old-computer-design-3-billion-investment) and when the cursor hits the bottom of the browser window, the window will not scroll downward automatically to continue the selection.

Doing an upward drag-select works fine.

This can be easily reproduced with QtTestbrowser compiled against qt-5.3.1.

QtTestBrowser compiled against qt-4.8.6 does not have this issue.