i am very sorry that this is pretty much of topic but i broke it
ok, well you sure made things weird in your copy, but that doesn't break (or fix) my copy
Strange ... For me (Win10, full HD), loop must start y<-220 to hang.
For y<-181 "floodFill" just return.
But for the -181, the first iteration seems to run forever, till crash.
"full HD"
I hadn't thought about the interaction between Snap! coordinates and stage size (like when you resize the right pane differently) and screen resolution etc, but I've seen it on a normal linux laptop and a windows workstation with a 4K monitor
Thanks! I guess I can just consider it in the pipeline. Meanwhile, the workaround of a 1pix border drawn around the stage seems workable.