repro: golint generated files problem

gen.pb.go

// Code generated by protoc-gen-go.
// source: contact-list-service.proto
// DO NOT EDIT!

/*
Package main is a generated protocol buffer package.

It is generated from these files:
	asdf.proto
	hasf.proto

It has these top-level messages:
	Start
	Stop
*/
package main

var foo_bar int

main.go

package main

import (
	"bufio"
	"bytes"
	"fmt"
	"io/ioutil"
	"log"
)

var (
	genHdr = []byte("// Code generated ")
	genFtr = []byte(" DO NOT EDIT.")
)

func main() {
	bb, err := ioutil.ReadFile("gen.pb.go")
	if err != nil {
		log.Fatal(err)
	}
	fmt.Println(isGenerated(bb))
}

// isGenerated reports whether the source file is generated code
// according the rules from https://golang.org/s/generatedcode.
func isGenerated(src []byte) bool {
	sc := bufio.NewScanner(bytes.NewReader(src))
	for sc.Scan() {
		b := sc.Bytes()
		if bytes.HasPrefix(b, genHdr) && bytes.HasSuffix(b, genFtr) && len(b) >= len(genHdr)+len(genFtr) {
			return true
		}
	}
	return false
}