graph/path: make AllShortest safe for length zero

gonum · Nov 20, 2018 · 5b0db96 · 5b0db96
1 parent 3b99883
commit 5b0db96
Showing 1 changed file with 3 additions and 0 deletions.
diff --git a/graph/path/shortest.go b/graph/path/shortest.go
@@ -197,6 +197,9 @@ type AllShortest struct {
 }
 
 func newAllShortest(nodes []graph.Node, forward bool) AllShortest {
+	if len(nodes) == 0 {
+		return AllShortest{}
+	}
 	indexOf := make(map[int64]int, len(nodes))
 	for i, n := range nodes {
 		indexOf[n.ID()] = i