net.IP(req.RemoteAddr) instead of net.ParseIP(req.RemoteAddr)

[dgryski]

package main

import (
	"net"
	"net/http"
)

func main() {
	var req http.Request
	_ = net.IP(req.RemoteAddr) // what was typed
	_ = net.ParseIP(req.RemoteAddr) // what what intended
}

Because net.IP's underlying type is a []byte, the net.IP conversion from req.RemoteAddr (which is a string) succeeds, but of course doesn't end up with the expected result.