Comments rendering issue related to array nodes

[Jebbs]

For a array field, we have a key node and a value node, for cases below, the comments set for slice node goes to the num node:

1. When the array is rendered inline (sure for an empty array), we set the key.LineComment, it is rendered at the wrong place:

   func Example_wrongComment() {
   	raw := `
   slice: [1]
   num: 1`
   	var d yaml.Node
   	err := yaml.Unmarshal([]byte(raw), &d)
   	if err != nil {
   		panic(err)
   	}
   	key := d.Content[0].Content[0]
   	if key.Value != "slice" {
   		panic("wrong node")
   	}
   	// Recurrence conditions:
   	// 1. slice is inlined
   	// 2. set key.LineComment
   	key.LineComment = "slice comment"
   	bs, err := yaml.Marshal(&d)
   	if err != nil {
   		panic(err)
   	}
   	fmt.Println(string(bs))
   	// Output:
   	// slice: [1]
   	// num: 1 # slice comment
   }

2. When the array is rendered in block style, we set the value.LineComment, it is rendered at the wrong place:

   func Example_wrongComment2() {
   	raw := `
   slice:
       - a
   num: 1`
   	var d yaml.Node
   	err := yaml.Unmarshal([]byte(raw), &d)
   	if err != nil {
   		panic(err)
   	}
   	key := d.Content[0].Content[0]
   	value := d.Content[0].Content[1]
   	if key.Value != "slice" {
   		panic("wrong node")
   	}
   	// Recurrence conditions:
   	// 1. slice is not inlined
   	// 2. set value.LineComment
   	value.LineComment = "slice comment"
   	bs, err := yaml.Marshal(&d)
   	if err != nil {
   		panic(err)
   	}
   	fmt.Println(string(bs))
   	// Output:
   	// slice:
   	//     - a
   	// num: 1 # slice comment
   }

A workaround for this issue is (similar like what happens in yaml.Unmarshal()):

func(key, value *yaml.Node) error {
	if len(values) == 0 {
		value.LineComment = "comment"
	} else {
		key.LineComment = "comment"
	}
	return nil
}

It seems that a non-empty array is always rendered in block style in my case. The workaround doesn't work when the array is rendered like a: [1,2,3], and I don't know when it happens.