Index out of range error in expect function

[CT-Zer0]

Describe the bug
Hi there. While I was fuzzing go-tomlv2, I am encountered with index out of range error. My test case is s=[ and I have assumed that parseValArray function doesn't check if '[' is the last element before performing parser.go:401 :

b = b[1:]

To Reproduce
This is my code (you can also find it in here) :

package main

import(
"github.com/pelletier/go-toml/v2"
"fmt"
)

type MyConfig struct {
      Version int
      Name    string
      Tags    []string
}


func main(){


doc := `s=[`

var cfg MyConfig
err := toml.Unmarshal([]byte(doc), &cfg)
if err != nil {
      fmt.Println("error")
}
fmt.Println("version:", cfg.Version)
fmt.Println("name:", cfg.Name)
fmt.Println("tags:", cfg.Tags)
}

Expected behavior
parseValArray should control boundaries and special characters before performing.
Versions

• go-toml: github.com/pelletier/go-toml/v2 v2.0.0-beta.3 h1:PNCTU4naEJ8mKal97P3A2qDU74QRQGlv4FXiL1XDqi4=
• go: 1.16.5
• operating system: e.g. Ubuntu 20

Additional context
This bug is found by offical dev.fuzz

[pelletier]

Good catch, thank you! Will look into it.

[pelletier]

This has been fixed by 40cfb6f!