Comment 6 for bug 1580774

Some debugging output from qtmir:

http://pastebin.ubuntu.com/16387328/

qtmir.mir.input: Received MirPointerEvent(x=1175,y=915,relative_x=145.75,relative_y=0)
qtmir.mir.input: Received MirPointerEvent(x=1243,y=915,relative_x=68.75,relative_y=0)
qtmir.mir.input: Unrecognized pointer event
qtmir.mir.input: Received MirPointerEvent(x=1181,y=1061,relative_x=-28.6186,relative_y=-2.60169)
qtmir.mir.input: Unrecognized pointer event
qtmir.mir.input: Received MirPointerEvent(x=1131,y=1058,relative_x=-78.1499,relative_y=-5.2086)
qtmir.mir.input: Received MirPointerEvent(x=1084,y=1056,relative_x=-47.501,relative_y=-2.64137)

The Unrecognized event must be "window leave", so USC thinking pointer left the unity8 window, so no more events are delivered.

You can also see that while the "invisible edge" doesn't always happen on the same x (weird!), there has to be a negative x delta before any other event is delivered (but no "window enter" event ¿?).