748e95ad50
With factory settings, steps to reproduce were: * Select "Collection 1" (in "RenderLayer") * Delete It might crash at this point, although maybe this crash is ASAN only. However, this was also doing some weird things that I've corrected now. It called outliner_build_tree in an operator callback. This should only be called in the main redraw function or so, not in regular handlers. Instead, we manually cleanup the tree to keep it valid.