A Mac bug with mouse-wheel scrolling (zooming and scrolling up and down in sidebars)
Open document with a block list visible and docked.
Click on document
Click in block list and mouse-wheel scroll up (or down).
Expected behaviour - block list view scrolls up (or down) until scrolling stops at limits of block list
Observed behaviour - block list view scrolls up (or down) until limit reached, then scrolling stops but document starts zooming (in or out as appropriate) instead. (!)