window resizing bug?

[Chris Gilbreth]

When I am resizing a windows with alt+rightmousebutton, if I click the
left mouse button as I am doing it and drag some more I encounter some
wierd behaviour. Try it and see; it should be very obvious. The border
drawn for resizing doesn't dissappear, the window decides it wants to
be a different size, etc. Clicking the titlebar afterward seems to put
things back to normal for the window itself, but elsewhere on the
screen there still may be artifacts.