Dragging selects text in items below

I have a vertical stack of items. As I drag one item over the the others, the text in the items that I drag over is getting selected, as would be expected if I click-and-dragged normally. What's the best way to suppress that behavior? Do I need to write callbacks for the dragged-over items to ignore that mouse-down event?

Reproduce the issue with a vertical stack and inspect the sortable drag behavior around items crossed during a drag. Determine how to prevent text selection without requiring callbacks on every dragged-over item; done means dragging an item no longer selects text in the items beneath it.

Written by the indexing model from the issue text.