index.html handling issues

[balopat]

I would expect index.html handling to work out of the box, but it doesn't seem that way.

package main

import (
	"github.com/gobuffalo/logger"
	"github.com/gobuffalo/packr/v2"
	"github.com/gobuffalo/packr/v2/plog"
	"net/http"
)

func main() {
	plog.Logger = logger.New(logger.DebugLevel)
	box := packr.New("test", "./broken_index")
	http.Handle("/", http.FileServer(box))
	http.ListenAndServe(":3000", nil)
}

under the broken_index directory I have an index.html and an index.htm, and the same under a sub directory: broken_index/sub an index.html and an index.htm.

As http.ServeFile redirects index.html calls to the / and http.serveFile contains the logic to check for existence of index.html under directories if f.IsDir(), I would expect "/", "/index.html", "/sub", "/sub/index.html" to work, but they come back with different errors:
"/" redirects to "http://localhost:3000//" and ends up in too many redirect calls.
"/sub/index.html" returns an empty response:

 curl http://localhost:3000/sub/index.html -v                                                                                 Sat Aug 31 16:44:00 2019
*   Trying ::1...
* TCP_NODELAY set
* Connected to localhost (::1) port 3000 (#0)
> GET /sub/index.html HTTP/1.1
> Host: localhost:3000
> User-Agent: curl/7.54.0
> Accept: */*
> 
< HTTP/1.1 301 Moved Permanently
< Location: ./
< Date: Sat, 31 Aug 2019 23:44:12 GMT
< Content-Length: 0
< 
* Connection #0 to host localhost left intact

I believe the underlying cause might be related to #211.

The /index.htm and /sub/index.htm urls work (just as a sanity check for my wiring/folder naming).