This one might cause some problems because it fixes a problem where the code didn’t do what the documentation said for some click and release events. The docs say to deliver |btn, left, top| to the proc. They didn’t. From what I can tell, they never did.
We also accept/present more button numbers instead of is always “1”. Button numbers start at one and increase from there in some pattern only you and your mouse device know. Cross platform? No! Your problem to sort out if the wheel click on OSX is a different number on Linux. Most people will stick with not caring which button. Now you have options.
If you’ve worked around the lack of |btn,l,t| on click and release then you may want to test your scripts with this beta. In this case, the documentation says the right thing and the code was incorrect. Long time wrong. See here
The beta also include the latest, almost nearly OK, plot widget.