From 20fbe4ffdf23cd79ff788f6841daceafa46e166e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Micha=C3=ABl=20Mora?= <michael.mora@ubisoft.com>
Date: Wed, 5 Aug 2020 14:00:24 +0200
Subject: [PATCH] EfficientSugiyamaLayoutAlgorithm Sweeping crashfix

Avoid sweeping crash when less than 2 layers.
---
 .../EfficientSugiyamaAlgorithm.DoCrossingMinimizations.cs      | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/GraphShape/Algorithms/Layout/Simple/Hierarchical/EfficientSugiyamaAlgorithm.DoCrossingMinimizations.cs b/src/GraphShape/Algorithms/Layout/Simple/Hierarchical/EfficientSugiyamaAlgorithm.DoCrossingMinimizations.cs
index b4ac68b..615e907 100644
--- a/src/GraphShape/Algorithms/Layout/Simple/Hierarchical/EfficientSugiyamaAlgorithm.DoCrossingMinimizations.cs
+++ b/src/GraphShape/Algorithms/Layout/Simple/Hierarchical/EfficientSugiyamaAlgorithm.DoCrossingMinimizations.cs
@@ -29,6 +29,9 @@ public partial class EfficientSugiyamaLayoutAlgorithm<TVertex, TEdge, TGraph>
         /// </summary>
         private void DoCrossingMinimizations()
         {
+            if (_layers.Count < 2)
+                return;
+
             int prevCrossings = int.MaxValue;
             int crossings = int.MaxValue;
             int phase = 1;