Reddit Link Fixer

fixer.js

// ==UserScript==
// @name         Old Reddit Link Fixer
// @author       Jurid
// @description  Fixes incorrect backslash placement in links on Old Reddit
// @match        https://*.reddit.com/*
// @version      16-Feb-2024
// ==/UserScript==

onmouseover = (event) => {
    const a = event.target.closest('.usertext-body a')

    if (a.matches('a[class*="expando-button"]')) return
    if (a.matches('a[href*="%5C_"]') && a.innerText === a.href.replaceAll('%5C_', '\\_')) removeBackslashes(a)
    if (a.matches('a[href*="reddit.com/media?url="]')) returnNormalMedia(a)
    if (a.innerText === a.href) a.innerText = a.href = decodeURI(a.href)
}

function removeBackslashes(a) {
    a.href = a.href.replaceAll('%5C_', '_');
    a.innerText = a.innerText.replaceAll('\\_', '_')
}

function returnNormalMedia(a) {
    a.href = decodeURIComponent(a.href.replace(/^.*?reddit\.com\/media\?url=/, ''))
}