net/http: ServeMux also eliminates repeating "/"

[egonelbre]

Just a documentation issue that - http.ServeMux (cleanPath) gets also rid of duplicate /-s. http.ServeMux already contains:

ServeMux also takes care of sanitizing the URL request path, redirecting any request containing . or .. elements to an equivalent .- and ..-free URL.

I'm not sure how to reword it nicely to include the case of empty path segments, hence I didn't make a CL. Here's shortest example:

package main
import ("fmt"; "net/http")
func main() {
    http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
        fmt.Fprintf(w, "%s", r.URL.Path)
    })
    http.ListenAndServe(":8001", nil)
}

/hello////world will redirect to /hello/world. From URI standpoint they are different and both valid (https://tools.ietf.org/html/rfc3986#section-3.3).

[bradfitz]

Related: #11757

@rsc, I can try to document these but feel free to steal these two as I still consider you the ServeMux owner. I've never really worked on it.

[rsc]

Thanks. I'll take these two.

[gopherbot]

CL https://golang.org/cl/17955 mentions this issue.