From 38b44302b741f8772985ce7c438a619da00cae2e Mon Sep 17 00:00:00 2001
From: Seth Bromberger <sbromberger@users.noreply.github.com>
Date: Mon, 17 Jul 2017 20:27:53 -0700
Subject: [PATCH] fixes DiGraph(DiGraph(...)) (#690)

Thanks, @juliohm!
---
 src/graphtypes/simplegraphs/simpledigraph.jl | 1 +
 test/graphtypes/simplegraphs/simplegraphs.jl | 3 +++
 2 files changed, 4 insertions(+)

diff --git a/src/graphtypes/simplegraphs/simpledigraph.jl b/src/graphtypes/simplegraphs/simpledigraph.jl
index 069e8fdda..49ba82b1d 100644
--- a/src/graphtypes/simplegraphs/simpledigraph.jl
+++ b/src/graphtypes/simplegraphs/simpledigraph.jl
@@ -76,6 +76,7 @@ function (::Type{SimpleDiGraph{T}})(g::SimpleDiGraph) where T<:Integer
     return SimpleDiGraph(ne(g), h_fadj, h_badj)
 end
 
+SimpleDiGraph(g::SimpleDiGraph) = copy(g)
 
 # constructor from abstract graph: DiGraph(graph)
 function SimpleDiGraph(g::AbstractSimpleGraph)
diff --git a/test/graphtypes/simplegraphs/simplegraphs.jl b/test/graphtypes/simplegraphs/simplegraphs.jl
index 330134426..6627a65ef 100644
--- a/test/graphtypes/simplegraphs/simplegraphs.jl
+++ b/test/graphtypes/simplegraphs/simplegraphs.jl
@@ -169,8 +169,11 @@ struct DummySimpleGraph <: AbstractSimpleGraph end
 
     gdx = CompleteDiGraph(4)
     for g in testdigraphs(gdx)
+        h = DiGraph(g)
+        @test g == h
         @test rem_vertex!(g, 2)
         @test nv(g) == 3 && ne(g) == 6
+        @test g != h
     end