[igraph] vertex.disjoint.paths and vertex.connectivity

[Massimo Franceschet]

The R igraph help for vertex.connectivity claims that "The maximum number of 
vertex disjoint paths between two vertices is the same as their vertex 
connectivity". However, this is true only if the two vertices are not linked by 
an edge. Here is a short example:

> g = graph(c(0,1), dir=FALSE)
> g
Vertices: 2 
Edges: 1 
Directed: FALSE 
Edges:
    e       
e [0] 0 -- 1

> vertex.connectivity(g, 0, 1)
Errore in vertex.connectivity(g, 0, 1) : 
  At flow.c:994 : vertices connected, Invalid value

> vertex.disjoint.paths(g, 0, 1)
[1] 1