[io] pass unmergeable objects through unchanged instead of skipping
[io] pass unmergeable objects through unchanged instead of skipping

olifre/root,karies/root,olifre/root,root-mirror/root,karies/root,olifre/root,karies/root,karies/root,root-mirror/root,olifre/root,olifre/root,root-mirror/root,root-mirror/root,olifre/root,root-mirror/root,root-mirror/root,karies/root,karies/root,karies/root,root-mirror/root,root-mirror/root,olifre/root,root-mirror/root,olifre/root,olifre/root,karies/root,karies/root,olifre/root,root-mirror/root,karies/root,root-mirror/root,olifre/root,karies/root