From 505fd2903253bd6b8601b9b259fb1d4f26bf7b2c Mon Sep 17 00:00:00 2001
From: Leon Mika <lmika@lmika.org>
Date: Fri, 24 May 2024 04:07:53 +0000
Subject: [PATCH] Fixed a panic which was thrown when trying to dereference an
 nil object

---
 ucl/objs.go              | 4 ++++
 ucl/testbuiltins_test.go | 4 ++++
 2 files changed, 8 insertions(+)

diff --git a/ucl/objs.go b/ucl/objs.go
index c978250..804ff71 100644
--- a/ucl/objs.go
+++ b/ucl/objs.go
@@ -161,6 +161,10 @@ func fromGoValue(v any) (object, error) {
 }
 
 func fromGoReflectValue(resVal reflect.Value) (object, error) {
+	if !resVal.IsValid() {
+		return nil, nil
+	}
+
 	switch resVal.Kind() {
 	case reflect.Slice:
 		return listableProxyObject{resVal}, nil
diff --git a/ucl/testbuiltins_test.go b/ucl/testbuiltins_test.go
index 2a44114..c8fc3e7 100644
--- a/ucl/testbuiltins_test.go
+++ b/ucl/testbuiltins_test.go
@@ -531,6 +531,9 @@ func TestBuiltins_Index(t *testing.T) {
 
 		{desc: "go list 1", expr: `goList | index 0 This`, want: "thing 1\n"},
 		{desc: "go list 2", expr: `goList | index 1 This`, want: "thing 2\n"},
+		{desc: "go list 3", expr: `goList | index 2`, want: "(nil)\n"},
+		{desc: "go list 4", expr: `goList | index 2 This`, want: "(nil)\n"},
+		{desc: "go list 5", expr: `goList | index 30`, want: "(nil)\n"},
 
 		{desc: "go struct 1", expr: `goStruct | index Alpha`, want: "foo\n"},
 		{desc: "go struct 2", expr: `goStruct | index Beta`, want: "bar\n"},
@@ -562,6 +565,7 @@ func TestBuiltins_Index(t *testing.T) {
 				return []*nest{
 					{This: "thing 1"},
 					{This: "thing 2"},
+					nil,
 				}, nil
 			})
 			inst.SetBuiltin("goStruct", func(ctx context.Context, args CallArgs) (any, error) {