I am working on a perl + Mojolicious web application and my front-end send a POST query containing accents in a `"a"` parameter (`"été"`) using charset `utf-8` as I can spy in chrome network tab. But server side script decode that parameter using a charset that I didn't expect.
I wrote the following script to reproduce that case.

```
use utf8; #script encoded in utf8 without bom
use Mojolicious::Lite; 
use Data::HexDump;
{
    require Mojolicious;
    say "perl $^V, Mojolicious: v", Mojolicious->VERSION, ", ", `chcp` ;
}

post '/' => sub{
        my $self = shift;
        my $params = $self->req->params->to_hash;
        app->log->debug("received data:\n", HexDump( $params->{a} ) );
        use Devel::Peek;
        Dump( $params->{a} );
        $self->render( text => "ok for '$params->{a}'" );
    };

if(my $pid = fork()){
    use Mojo::UserAgent;
    my $t = Mojo::UserAgent->new;
    #simulate front-end query
    my $tx  = $t->post('http://127.0.0.1:3042/' => 
                            { 'Content-Type' => 'application/x-www-form-urlencoded; charset=UTF-8' }, 
                            form => {  a => 'été'} 
                        );
    my $res = $tx->res->body;
    say "result:\n", HexDump($res);
    use Devel::Peek;
    Dump( $res );
    kill 'SIGKILL', $pid;
    exit(0);
}

app->start(qw(daemon --listen http://*:3042 ));

```

The ouput of this script was:

```
perl v5.20.1, Mojolicious: v6.05, Page de codes active : 850

[Tue May 26 12:31:15 2015] [info] Listening at "http://*:3042"
Server available at http://127.0.0.1:3042
[Tue May 26 12:31:16 2015] [debug] Your secret passphrase needs to be changed
[Tue May 26 12:31:16 2015] [debug] POST "/"
[Tue May 26 12:31:16 2015] [debug] Routing to a callback
[Tue May 26 12:31:16 2015] [debug] received data:

          00 01 02 03 04 05 06 07 - 08 09 0A 0B 0C 0D 0E 0F  0123456789ABCDEF

00000000  E9 74 E9                                           .t.

SV = PVMG(0x5a7a198) at 0x4dce730
  REFCNT = 1
  FLAGS = (POK,pPOK,UTF8)
  IV = 0
  NV = 0
  PV = 0x5b62c48 "\303\251t\303\251"\0 [UTF8 "\x{e9}t\x{e9}"]
  CUR = 5
  LEN = 10
[Tue May 26 12:31:16 2015] [debug] 200 OK (0.005052s, 197.941/s)
result:
          00 01 02 03 04 05 06 07 - 08 09 0A 0B 0C 0D 0E 0F  0123456789ABCDEF

00000000  6F 6B 20 66 6F 72 20 27 - C3 A9 74 C3 A9 27        ok for '..t..'

SV = PV(0x41a73e8) at 0x4927070
  REFCNT = 1
  FLAGS = (PADMY,POK,IsCOW,pPOK)
  PV = 0x5aa1328 "ok for '\303\251t\303\251'"\0
  CUR = 14
  LEN = 16
  COW_REFCNT = 1

```

So we can see that the server receive the `"a"` parameter in an string flagged `utf8` that contain the buffer `"\x{e9}t\x{e9}"`.

I was expecting `"été"` with the hexa `"C3 A9 74 C3 A9"`.

What is wrong?