Hi Bert,
I'm not really qualified to "review" this change, but as far as I can tell in running it in my image (EToys 3.1 on Windows), it makes the right button handling much more intuitive. If the VM is set correctly to use 2 button mouse (i.e. not 1 or 3), then as far as I can see we don't need the fix. But in its default configuration, it's set as a 3 button mouse, and then your fix enables users such as me with only 2 buttons to access both context menu and halos nicely.
thanks!
cheers, Simon
PS: My original problem was that I didn't know about a VM setting for number of mouse buttons.