.

wcfs/δbtail.go

@@ -241,7 +241,9 @@ func (tidx trackIndex) ApplyΔ(δ *δtrackIndex) {
 		}
 
 		tidx[oid] = &nodeTrack{parent: δt.parent, nchild: 0}
-		δnchild[δt.parent] += 1 // remeber to nchild++ in parent
+		if δt.parent != zodb.InvalidOid {
+			δnchild[δt.parent] += 1 // remeber to nchild++ in parent
+		}
 	}
 	for parent, δnc := range δnchild {
 		tidx[parent].nchild += δnc
@@ -785,6 +787,7 @@ func treediff(ctx context.Context, root zodb.Oid, δtops SetOid, δZTC SetOid, t
 		// DEL k -> Tkextra += k
 		// +k    -> Tkextra -= k
 		tracef("-> δtop: %v\n", δtop)
+		tracef("-> δtrackTop: %v\n", δtrackTop)
 		for k,δv := range δtop {
 			δT[k] = δv
 		}