Re: [libmicrohttpd] How can I decode the form-data fields with MHD_http_unescape() function?

[silvioprog]

On Tue, Feb 16, 2016 at 9:29 AM, Evgeny Grin <address@hidden> wrote:

There is a conflict between standards.
HTML states that "+" must be decoded to space in url-encoding.
https://www.w3.org/TR/html/forms.html#url-encoded-form-data
RFC 3986 doesn't assume any special treatment of "+".
https://tools.ietf.org/html/rfc3986

I found a draft talking "... and the plus sign may be used to represent space characters.":

https://tools.ietf.org/html/draft-hoehrmann-urlencoded-01

But I don't know if this draft was accepted as standard.

However, I did some tests with PHP and JS, that shows MHD_http_unescape() is right:

<?php

  $s = "Silvio Clécio";

  $enc = urlencode($s);

  $rawenc = rawurlencode($s);

  echo "enc: " . $enc . "<br />";

  echo "rawenc: " . $rawenc. "<br />";

  echo "<br />";

  echo "urldecode(enc): " . urldecode($enc) . "<br />";

  echo "urldecode(rawenc): " . urldecode($rawenc) . "<br />";

  echo "<br />";

  echo "rawurldecode(enc): " . rawurldecode($enc). "<br />";

  echo "rawurldecode(rawenc): " . rawurldecode($rawenc);

?>

Result:

enc: Silvio+Cl%C3%A9cio

rawenc: Silvio%20Cl%C3%A9cio

urldecode(enc): Silvio Clécio

urldecode(rawenc): Silvio Clécio

rawurldecode(enc): Silvio+Clécio

rawurldecode(rawenc): Silvio Clécio

---

var s = "Silvio Clécio";

var enc = encodeURI(s);

var encCmp = encodeURIComponent(s);

console.log("enc: ", enc);

console.log("encCmp: ", encCmp);

console.log();

console.log("decodeURI(enc): ", decodeURI(enc));

console.log("decodeURI(encCmp): ", decodeURI(encCmp));

console.log();

console.log("decodeURIComponent(enc): ", decodeURIComponent(enc));

console.log("decodeURIComponent(encCmp): ", decodeURIComponent(encCmp));

Result:

enc:  Silvio%20Cl%EF%BF%BDcio

encCmp:  Silvio%20Cl%EF%BF%BDcio

decodeURI(enc):  Silvio Clécio

decodeURI(encCmp):  Silvio Clécio

decodeURIComponent(enc):  Silvio Clécio

decodeURIComponent(encCmp):  Silvio Clécio

And:

var s = "Silvio+Cl%C3%A9cio";

console.log("decodeURI(s): ", decodeURI(s));

console.log("decodeURIComponent(s): ", decodeURIComponent(s));

Result:

decodeURI(s):  Silvio+Clécio

decodeURIComponent(s):  Silvio+Clécio

So MHD_http_unescape() looks like rawurldecode() and decodeURI()/decodeURIComponent(). However I need to replace the plus chars because I don't know what format the end user will send. I going to try MHD_OPTION_UNESCAPE_CALLBACK ...

Thanks for answer -CG and -EG! :-)

--

Silvio Clécio