After resizing the map control such that the visible area overflows, there are issues:
- the map control turns black until the next redraw
- the screen-loc parameter of mouse events is wrong.
I've seen this on other computers: Windows 7, 8.1. I got a report of someone else seeing this. This is a pretty recent bug.
For a demo, run the Map Zoom demo and comment out the
animate() lines in demo-map.dm. They're actually secretly there to hide this issue, but they're less effective when running in Dream Daemon because redraws are less frequent.