[boost] [Graphs] Bug in directed edge-connectivity algorithm

Subject: [boost] [Graphs] Bug in directed edge-connectivity algorithm
From: Michele Borassi (michele.borassi_at_[hidden])
Date: 2015-06-15 05:40:29

Dear all,
my name is Michele Borassi, and I am a user of Boost Graph library, 
version 1.58.0.

I have found a problem in the edge connectivity algorithm: if the input 
is a directed path with 3 vertices (0, 1, 2) and 2 edges ((0,1), (1,2)), 
the output is 1 (while it should be 0, since the graph is not strongly 
connected). However, if edge (1,0) is added, the output becomes 
(correctly) 0. A minimal working example that shows this issue is 
attached; my output is:

Path of 3 vertices and 2 edges.
The edge connectivity is 1.
Added edge (1,0): now there are 3 edges.
The edge connectivity becomes 0.

Could you also explain me which is the best way to report a bug? I have 
checked your web page http://www.boost.org/development/bugs.html, but 
all links seem to be broken.

Waiting for your answer, I thank you in advance,
Michele Borassi