ref: e4306a6036f8a02b8714b5934c358f9dcc8a0eec
parent: 8b91de196c8cb21c57763fe80010edb889a7a8f6
author: Simon Tatham <anakin@pobox.com>
date: Tue Jan 25 13:07:08 EST 2005
Sanitising the mouse input data was a good idea, but my implementation sucked. Revise it completely. [originally from svn r5209]