It might be that FormData
and multipart/form-data
are not well supported on those platforms. Need to look into it more (later).
Meanwhile, try the more typical approach; use application/x-www-form-urlencoded
or JSON.
EG:
GM_xmlhttpRequest ( {
method: "POST",
url: "http://myserver.org/mysscript.py",
data: "image64=" + encodeURIComponent (img64),
headers: {
"Content-Type": "application/x-www-form-urlencoded"
},
onload: function (response) {
console.log ("gut response");
$("#input").get()[0].value=response.responseText;
}
} );