Mutator doesn't work well with firstOrCreate

[0xtoorich]

• Laravel Version: 5.6.11
• PHP Version: 7.2.3
• Database Driver & Version: MySQL 5.7.21

Description:

// ips table migration

Schema::create('ips', function (Blueprint $table) {
    $table->increments('id');
    $table->integer('ip')->unsigned()->index();
});

// Ip model

public function getIpAttribute($value)
{
    return long2ip($value);
}

public function setIpAttribute($value)
{
    $this->attributes['ip'] = ip2long($value);
}

// Controller
Ip::firstOrCreate(['ip' => $request->ip()]);

Steps To Reproduce:

1. Visit the route many times.
2. Got duplicate records, the firstOrCreate doesn't work correctly.

[staudenmeir]

#14649