Marshal doesn't handle multiple struct tag fields properly

[dhiltgen]

If you have multiple struct field tags, and the first one isn't "toml" then it's ignored and the default logic kicks in for naming the fields in the serialized output.

Example:

package main

import (
        "fmt"
        "github.com/naoina/toml"
)

type cfg struct {
        MySetting string `json:"JSONMySetting",toml:"toml_my_setting"` // Does not work
        //MySetting string `toml:"toml_my_setting",json:"JSONMySetting"` // Works
}

func main() {
        c1 := cfg{"foo"}

        data, err := toml.Marshal(&c1)
        if err != nil {
                panic(err)
        }
        fmt.Printf("Serialized: %s", string(data))

        var c2 cfg
                
        if err := toml.Unmarshal(data, &c2); err != nil {
                panic(err)
        }
        fmt.Printf("Unmarshaled: %#v\n", c2)
}

Expected output:

Serialized: toml_my_setting="foo"
Unmarshaled: main.cfg{MySetting:"foo"}

Actual output:

Serialized: my_setting="foo"
Unmarshaled: main.cfg{MySetting:"foo"}

[dhiltgen]

Nevermind, it's supposed to be a space, not a comma.