Using scrollwheel on a drawn marking until it is as small at it can be will then scroll zoom instead
I found this bug in 2.2.1 (possible 2.2.0 but i think not in versions before that).
Make a selection/marking by drawing with dots (so not a round one). I then use the scrollwheel hovering inside it and scrolling down to make it as small as possible. After that, scrolling inside the marker will only scroll the image zoom, not make my marking bigger or smaller.