Client.Do will not uncompress response body

clientDoGzip.go

package main

// run this file with `go run clientDoGzip.go, and then file tmp.out to verify body is gzipped

import "net/http"
import "io/ioutil"
import "bytes"
import "fmt"
import "log"
import "compress/gzip"

func main() {
        req,err := http.NewRequest("GET","http://bash.cyberciti.biz/wp-content/themes/bashshell/custom/images/headerbg.gif",nil)
        if err != nil {log.Fatal(err)}
        req.Header.Set("Accept-Encoding","gzip")
        if err != nil {log.Fatal(err)}
        client := &http.Client{}
        resp,err := client.Do(req)
        if err != nil {log.Fatal(err)}

        for k,v := range resp.Header {
                fmt.Println(k+":",v)
        }
        b,err := ioutil.ReadAll(resp.Body)
        if err != nil {
                fmt.Println(err)
                return
        }
        r,err := gzip.NewReader(bytes.NewReader(b))
        if err == nil {
                log.Println("Hold it, resp.Body should be plain text!")
                if _,err := r.Read([]byte{0}); err == nil {
                        log.Println("And we can even read the first byte!")
                }
        }
        ioutil.WriteFile("tmp.out",b,0666)
}