From ed40eddafd5d7b1663912f49b41f2567bc1a3771 Mon Sep 17 00:00:00 2001
From: Oliver Gugger <gugger@gmail.com>
Date: Thu, 16 Jun 2022 10:10:27 +0200
Subject: [PATCH] autopilot: return early for empty graph
This fixes an issue where the diameter calculation would crash if the
graph is empty.
---
autopilot/simple_graph.go | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/autopilot/simple_graph.go b/autopilot/simple_graph.go
index f7bf4c12c..08476414b 100644
--- a/autopilot/simple_graph.go
+++ b/autopilot/simple_graph.go
@@ -132,6 +132,11 @@ func (graph *SimpleGraph) shortestPathLengths(node int) map[int]uint32 {
// thisLevel contains the nodes that are explored in the round.
thisLevel := make([]int, 0, graphOrder)
+ // Abort if we have an empty graph.
+ if len(graph.Adj) == 0 {
+ return seen
+ }
+
// We discover other nodes in a ring-like structure as long as we don't
// have more nodes to explore.
for len(nextLevel) > 0 {