JiraLinks.js

// ==UserScript==
// @name         Jira - External Links Fixer
// @namespace    https://github.com/smugzombie
// @version      0.1.0
// @description  Jira is dumb and opens all links in the same tab as the issue you are viewing.. causing you to lose the issue. This forces external links to open seperately
// @author       SmugZombie (github.com/smugzombie
// @match        https://*.atlassian.net/*
// @icon         https://www.google.com/s2/favicons?sz=64&domain=atlassian.net
// @grant        none
// @downloadURL  https://put.wtf/media/scripts/JiraLinks.js?version=0.1.0
// @updateURL    https://put.wtf/media/scripts/JiraLinks.js?version=0.1.0
// ==/UserScript==

(function() {
    let myLinks = document.getElementsByTagName("a"); // Grab all links on page
    let ignoredHref = window.location.href.split("atlassian.net")[0] + "atlassian.net"; //Figure out the current atlassian url to ignore later
    // Loop through all links
    for (var i = myLinks.length - 1; i >= 0; i--) {
        let linkhref = myLinks[i].href;
        if(linkhref.includes(ignoredHref)){
            // If the link includes the ignoredHref, its local, don't open in new window
        }else{ // Othgerwise, change the target to "_blank" so it opens in a new tab
            myLinks[i].target = "_blank";
        }
    }
})();