Lively Kernel is much better nowadays in fb. There are sill some problems: 1) Open LK 2) Go to "More complex sample widgets" 3) Drag the "map" itself out of it's map widget and drop it somewhere 4) Use the controls to start translating the map, or scale it Notice the repainting problems. Not yet investigated it's origin.
I'm not sure this is related to feature-branch or not. I was also able to reproduce these, by clicking on the lively kernel map and dragging around quickly. The issue appears to occur when the next tile image hasn't been loaded correctly, but I'm not sure. I'm also not sure if its required for the map to be "dragged out" (which doesn't seem to happen repeatably for me). Maybe RenderSVGImage isn't always invalidating its old bounds rect?
Ah! RenderSVGImage does not have its own layout() method. That's probably the issue. It's probably not invalidating the old bounds rect properly.
I'm not able to reproduce this anymore.