GM.xmlHttpRequest not passing `blob` or `arraybuffer` responses back correctly on iOS

[fx-chun]

On iOS Userscripts, the following yields {} and undefined respectively for a given URL to a binary file:

GM.xmlHttpRequest({
                    method: "GET",
                    url: href,
                    responseType: "arraybuffer", // or blob
                    onload: function(res) {
                        console.log(res.response);
                        console.log(res.response.prototype);
                    }
})

.. whereas the same on Tampermonkey passes back a complete ArrayBuffer as part of its response.

[quoid]

@noneucat can you provide a complete example the xmlHttpRequest, including the url?

[fx-chun]

Ahh, sure thing :) sorry. Here's a complete userscript that exhibits the bug:

// ==UserScript==
// @name         #212
// @match        https://example.com/
// @grant        GM.xmlHttpRequest
// ==/UserScript==

(function() {
    'use strict';

    setTimeout(() => {
        GM.xmlHttpRequest({
            method: "GET",
            url: "https://test-videos.co.uk/vids/bigbuckbunny/webm/vp8/1080/Big_Buck_Bunny_1080_10s_1MB.webm",
            responseType: "arraybuffer",
            headers: {
                "Accept": "video/webm"
            },
            onload: function(response) {
                console.log(response);
                console.log(response.response); // {}
                console.log(response.response.byteLength); // undefined
            }
        })
    }, 3000);
})();

[quoid]

@noneucat Thanks!

[quoid]

This is an issue with how the response is sent back to the content script.

Hopefully next patch update will contain a fix. I am assuming other non-text responseTypes are also not working well. All the other responseTypes should be validated before the fix goes live.

If anyone feels like contributing:

Associated code

userscripts/extension/Userscripts Extension/Resources/background.js

Line 185 in 116eb4e

function xhrHandleEvent(e, xhr, tab, xhrId) {