Progress chart breaks after changing zoom level

[selimsum]

Steps to reproduce:

Press and hold Ctrl while turning the mouse wheel to zoom in or out a few times. Problem occurs after zooming in/out a few steps, not if you zoom in/out just a single step.

I came across this issue because of a broken mouse button and I don't think this is a big deal, but I'm reporting it just in case someone wants to take a look at it.

[mathjazz]

I was able to reproduce it a couple of times, but not reliably.

I believe mousewheel.with_meta.action and/or mousewheel.with_control.action must be set to "3" for the issue to be reproducible.