Clamp the winit backend's own CSD margin offset to non-negative too

Same fix as the udev backend's matching content-position code: a real
CSD shadow margin (dwindow.geometry().loc) is never negative, but a
live Firefox window was observed reporting loc = (-10, -10) despite
sync_geometry's tiled-state hint telling it to reserve no margin at
all. This path (rounded_content_element, a live GLES shader rendering
the client's own texture directly, not a separate pre-shifted buffer)
doesn't have the udev backend's double-application bug, but it shares
the same single-subtraction call and so needed the same clamp.

0 files changed, 0 insertions, 0 deletions