IGMinimumSeparators misbehaves with directed graphs

[szhorvat]

According to the documentation, edge directions should be ignored.

In reality, empty results are returned for directed graphs.

In[385]:= IGMinimumSeparators@CycleGraph[4, DirectedEdges -> True]
Out[385]= {}

In[386]:= IGMinimumSeparators@CycleGraph[4, DirectedEdges -> False]
Out[386]= {{2, 4}, {1, 3}}

Upstream bug: https://github.com/igraph/igraph/issues/992

[Juddd]

I also don't think it works normally with undircted graph,see this

edges = {TX -> R1, R1 -> R3, R3 -> R5, R5 -> RX, TX -> R2, R2 -> R4, 
   R4 -> R6, R6 -> RX, R1 -> R2, R2 -> R3, R3 -> R4, R4 -> R5, 
   R5 -> R6, TX -> R7, TX -> R8, R7 -> R9, R9 -> R6, R9 -> RX, 
   R8 -> R6};
g = UndirectedGraph[edges, VertexLabels -> "Name"]
IGMinimumSeparators[g]

[szhorvat]

I think this result is correct. Can you explain more why you think it is not?

Deleting these vertex sets disconnects the graph. They are indeed the smallest possible sets that will disconnect it.

[Juddd]

I'm soory,I make a mistake.There is a isolated vertex(R8) when we drop the vertice R6 and TX..The result is right indeed.

[szhorvat]

Milestone removed as there is a workaround for this in Mma code. Will keep the bug open until the issue is fixed in the C code upstream.