Comment 79 for bug 239462

(In reply to comment #74)
> This patch has the side effect of not being able to reshow the tooltip.
> Previously if the tooltip disappeared you could move the mouse a bit and the
> tooltip would reappear, now it won't, is that expected/desired?

If you follow the discussion above, you'll see that this is the desired behaviour. The tooltip remains indefinitely visible so long as the mouse remains stationary on a node and only hides once the mouse moves more than the tolerance of 7 pixels horizontally or vertically. The tooltip will reappear if the mouse leaves the node and re-enters it.