When a rectangle side has zero length, the miter join generator is
confused because it cannot recover the join angle. This patch avoids
that by using artificially non-degenerate previous and next vertices.
Signed-off-by: Giovanni Mascellani <gio@debian.org>
Signed-off-by: Henri Verbeet <hverbeet@codeweavers.com>
Signed-off-by: Alexandre Julliard <julliard@winehq.org>