Uri.of_string does not actually invoke pct_decode

[nojb]

Is this expected behaviour?

> let s = "udp%3A//tracker.openbittorrent.com%3A80";;
> let uri = Uri.of_string s;;
val uri : Uri.t = <abstr>
> Uri.scheme uri;;
- : string option = None
> let uri = Uri.of_string (Uri.pct_decode s);;
val uri : Uri.t = <abstr>
> Uri.scheme uri;;
- : string option = Some "udp"

[dsheets]

This is expected behavior:

> let s = "udp%3A//tracker.openbittorrent.com%3A80/%3A?%3A#%3A";;
val s : string = "udp%3A//tracker.openbittorrent.com%3A80/%3A?%3A#%3A"
> let uri = Uri.of_string s;;
val uri : Uri.t = udp%3A//tracker.openbittorrent.com%3A80/%3A?:#:
>  Uri.path uri;;
- : string = "udp://tracker.openbittorrent.com:80/:"

This is because ":" is not a valid character in the path component of a URI. If you know you have a URI which has syntactic components percent-encoded, you should first percent decode it before parsing it with Uri.of_string.

If the URI was percent-encoded because it was being passed as a component of another URI, this percent decoding will happen automatically and you can do something like:

let uri = match Uri.(get_query_param (of_string request_uri)) "target" with
| None -> raise Not_found
| Some t -> Uri.of_string t

I think this behavior makes sense but I'm interested in hearing your opinion. Please note, there is also a rather nasty percent-encoding bug which I intend to fix soon (later today?).

[nojb]

Dear David,

Thanks very much for your reply! I am rather ignorant about the technicalities
of the URI format, but the comment in uri.mli is

(** Convert a percent-encoded string into a URI structure *)
val of_string : string -> t

which is confusing IMHO.

Thanks again!
Nicolas

On 28 Dec 2013, at 16:30, David Sheets [email protected] wrote:

This is expected behavior:

let s = "udp%3A//tracker.openbittorrent.com%3A80/%3A?%3A#%3A";;
val s : string = "udp%3A//tracker.openbittorrent.com%3A80/%3A?%3A#%3A"
let uri = Uri.of_string s;;
val uri : Uri.t = udp%3A//tracker.openbittorrent.com%3A80/%3A?:#:
Uri.path uri;;

• : string = "udp://tracker.openbittorrent.com:80/:"
  This is because ":" is not a valid character in the path component of a URI. If you know you have a URI which has syntactic components percent-encoded, you should first percent decode it before parsing it with Uri.of_string.

If the URI was percent-encoded because it was being passed as a component of another URI, this percent encoding will happen automatically and you can do something like:

let uri = match Uri.get_query_param (of_string request_uri) "target" with
| None -> raise Not_found
| Some t -> Uri.of_string t
I think this behavior makes sense but I'm interested in hearing your opinion. Please note, there is also a rather nasty percent-encoding bug which I intend to fix soon (later today?).

—
Reply to this email directly or view it on GitHub.

[dsheets]

Oh, I see. That is quite confusing. I will explain more clearly what of_string does in my patch to fix the above percent-encoding bug. It is quite subtle as the Uri.(to_string (of_string uri_str)) will actually perform something like normalization. Thanks for your report!