QHeaderView manual test auto-scrolling is broken

There is an issue with the QHeaderview when selection is released in auto-scroll mode. The selection will start flashing and the selected cells wil gradually expend, to the lower and the higher cells. The application used is the QHeaderview manual test.*

Expected outcome:
The auto scroll mode enables to automatically scroll while selecting cells.

Actual outcome:
Once the mouse button is release while auto-scroll is scrolling, the selection will start to flash and gradually be expended (towards both cell 1 and cell 200).