From 55ef966b88223a46ed51f37f11bd73b1a4791510 Mon Sep 17 00:00:00 2001
From: Mitchell Hashimoto <mitchell.hashimoto@gmail.com>
Date: Wed, 14 Sep 2016 13:35:54 -0700
Subject: [PATCH] config/module: tree.Child on a nil tree works

---
 config/module/tree.go      | 4 ++++
 config/module/tree_test.go | 5 +++++
 2 files changed, 9 insertions(+)

diff --git a/config/module/tree.go b/config/module/tree.go
index a0818bfa4..8a322650b 100644
--- a/config/module/tree.go
+++ b/config/module/tree.go
@@ -66,6 +66,10 @@ func (t *Tree) Config() *config.Config {
 
 // Child returns the child with the given path (by name).
 func (t *Tree) Child(path []string) *Tree {
+	if t == nil {
+		return nil
+	}
+
 	if len(path) == 0 {
 		return t
 	}
diff --git a/config/module/tree_test.go b/config/module/tree_test.go
index f455c2a02..d46d5ed27 100644
--- a/config/module/tree_test.go
+++ b/config/module/tree_test.go
@@ -12,6 +12,11 @@ import (
 )
 
 func TestTreeChild(t *testing.T) {
+	var nilTree *Tree
+	if nilTree.Child(nil) != nil {
+		t.Fatal("child should be nil")
+	}
+
 	storage := testStorage(t)
 	tree := NewTree("", testConfig(t, "child"))
 	if err := tree.Load(storage, GetModeGet); err != nil {