[winswitch] xpra coordinate mapping error with dual screen

[Martin Ebourne]

I've recently upgraded to xpra 0.9.2 and now 0.9.4 from a much older
version. I also switched to using Xdummy in the process. Now I am
getting an intermittent and very odd problem with the mouse pointer
coordinates.

After lots of quite normal operation suddenly the mouse pointer clicks
will go wrong on the second (right hand side) screen. Clicking with the
mouse will register the click somewhere else on the same screen, the y
coordinate will be correct but the x will be much reduced, usually it
will register the click near the left hand edge of the screen even if I
clicked near the right hand edge. The click may turn up in an entirely
different xpra window if they are suitably arranged.

Non-xpra windows are not affected and the left hand screen carries on
working normally. Dragging a window from the rhs screen to the lhs
screen fixes the problem for that window, and putting it back causes it
to go wrong again. If the window is split between screens then the part
on the lhs works fine and the part on the rhs exhibits the problem.

The only remedy I've found is to restart the client which solves it
until the next time. This has happened on average maybe once per 20
hours of use so is not common.

There are no log messages from either end when this happens. Any ideas?

Cheers,
Martin