get_distance() with topology_only=True should return number of edges, not nodes (ete3)

[lenacoll]

get_distance(target, target2, topology_only=True) returns (according to the documentation) the number of nodes on the path between target and target2. Without the flag topology_only=True, it returns the branch length sum between the two targets.
It therefore seems more intuitive to return the number of edges connecting the two targets if topology_only=True.
It especially seems odd that two nodes connected by an edge have distance 0.