browser.warnOnQuit Skript funktioniert im aktuellem Nightly nicht mehr

(function() {

  if (window.__SSi != 'window0')
    return;

  const lazy = {};
  ChromeUtils.defineESModuleGetters(lazy, {
    BrowserGlue: "resource:///modules/BrowserGlue.sys.mjs"
  });

  lazy.BrowserGlue.prototype._onQuitRequest =
  function BG__onQuitRequest(aCancelQuit, aQuitType) {

    // If user has already dismissed quit request, then do nothing
    if (aCancelQuit instanceof Ci.nsISupportsPRBool && aCancelQuit.data) {
      return;
    }

    // There are several cases where we won't show a dialog here:
    // 1. There is only 1 tab open in 1 window
    // 2. browser.warnOnQuit == false
    // 3. The browser is currently in Private Browsing mode
    // 4. The browser will be restarted.
    // 5. The user has automatic session restore enabled and
    //    browser.sessionstore.warnOnQuit is not set to true.
    // 6. The user doesn't have automatic session restore enabled
    //    and browser.tabs.warnOnClose is not set to true.
    //
    // Otherwise, we will show the "closing multiple tabs" dialog.
    //
    // aQuitType == "lastwindow" is overloaded. "lastwindow" is used to indicate
    // "the last window is closing but we're not quitting (a non-browser window is open)"
    // and also "we're quitting by closing the last window".

    if (aQuitType == "restart" || aQuitType == "os-restart") {
      return;
    }

    // browser.warnOnQuit is a hidden global boolean to override all quit prompts.
    if (!Services.prefs.getBoolPref("browser.warnOnQuit")) {
      return;
    }

    var windowcount = 0;
    var pagecount = 0;
    let pinnedcount = 0;
    for (let win of BrowserWindowTracker.orderedWindows) {
      if (win.closed) {
        continue;
      }
      windowcount++;
      let tabbrowser = win.gBrowser;
      if (tabbrowser) {
        pinnedcount += tabbrowser._numPinnedTabs;
        pagecount += tabbrowser.visibleTabs.length - tabbrowser._numPinnedTabs;
      }
    }

    // No windows open so no need for a warning.
    if (!windowcount) {
      return;
    }

    // browser.warnOnQuitShortcut is checked when quitting using the shortcut key.
    // The warning will appear even when only one window/tab is open. For other
    // methods of quitting, the warning only appears when there is more than one
    // window or tab open.
    let shouldWarnForShortcut =
      this._quitSource == "shortcut" &&
      Services.prefs.getBoolPref("browser.warnOnQuitShortcut");
    let shouldWarnForTabs =
      //pagecount >= 2 &&
      Services.prefs.getBoolPref("browser.tabs.warnOnClose");
    if (!shouldWarnForTabs && !shouldWarnForShortcut) {
      return;
    }

    if (!aQuitType) {
      aQuitType = "quit";
    }

    let win = BrowserWindowTracker.getTopWindow();

    // Our prompt for quitting is most important, so replace others.
    win.gDialogBox.replaceDialogIfOpen();

    let titleId, buttonLabelId;
    if (windowcount > 1) {
      // More than 1 window. Compose our own message.
      titleId = {
        id: "tabbrowser-confirm-close-windows-title",
        args: { windowCount: windowcount },
      };
      buttonLabelId = "tabbrowser-confirm-close-windows-button";
    } else if (shouldWarnForShortcut) {
      titleId = "tabbrowser-confirm-close-tabs-with-key-title";
      buttonLabelId = "tabbrowser-confirm-close-tabs-with-key-button";
    } else {
      titleId = {
        id: "tabbrowser-confirm-close-tabs-title",
        args: { tabCount: pagecount },
      };
      buttonLabelId = "tabbrowser-confirm-close-tabs-button";
    }

    // The checkbox label is different depending on whether the shortcut
    // was used to quit or not.
    let checkboxLabelId;
    if (shouldWarnForShortcut) {
      const quitKeyElement = win.document.getElementById("key_quitApplication");
      const quitKey = ShortcutUtils.prettifyShortcut(quitKeyElement);
      checkboxLabelId = {
        id: "tabbrowser-confirm-close-tabs-with-key-checkbox",
        args: { quitKey },
      };
    } else {
      checkboxLabelId = "tabbrowser-confirm-close-tabs-checkbox";
    }

    let [
      title,
      buttonLabel,
      checkboxLabel,
    ] = win.gBrowser.tabLocalization.formatMessagesSync([
      titleId,
      buttonLabelId,
      checkboxLabelId,
    ]);

    let warnOnClose = { value: true };
    let flags =
      Services.prompt.BUTTON_TITLE_IS_STRING * Services.prompt.BUTTON_POS_0 +
      Services.prompt.BUTTON_TITLE_CANCEL * Services.prompt.BUTTON_POS_1;

    // 1 Fenster mit höchstens 1 nicht angehefteter Tab
    if (windowcount == 1 && pagecount < 2 && this._quitSource != "shortcut") {
      let url = win.gBrowser.currentURI.spec;
      if (url == 'about:newtab' || url == 'about:home') {
        return;
      }
      title.value = "Fenster schließen?";
      buttonLabel.value = "Schließen";
      checkboxLabel.value = null;
    }

    // buttonPressed will be 0 for closing, 1 for cancel (don't close/quit)
    let buttonPressed = Services.prompt.confirmEx(
      win,
      title.value,
      null,
      flags,
      buttonLabel.value,
      null,
      null,
      checkboxLabel.value,
      warnOnClose
    );
    Services.telemetry.setEventRecordingEnabled("close_tab_warning", true);
    let warnCheckbox = warnOnClose.value ? "checked" : "unchecked";

    let sessionWillBeRestored =
      Services.prefs.getIntPref("browser.startup.page") == 3 ||
      Services.prefs.getBoolPref("browser.sessionstore.resume_session_once");
    Services.telemetry.recordEvent(
      "close_tab_warning",
      "shown",
      "application",
      null,
      {
        source: this._quitSource,
        button: buttonPressed == 0 ? "close" : "cancel",
        warn_checkbox: warnCheckbox,
        closing_wins: "" + windowcount,
        closing_tabs: "" + (pagecount + pinnedcount),
        will_restore: sessionWillBeRestored ? "yes" : "no",
      }
    );

    // If the user has unticked the box, and has confirmed closing, stop showing
    // the warning.
    if (buttonPressed == 0 && !warnOnClose.value) {
      if (shouldWarnForShortcut) {
        Services.prefs.setBoolPref("browser.warnOnQuitShortcut", false);
      } else {
        Services.prefs.setBoolPref("browser.tabs.warnOnClose", false);
      }
    }

    this._quitSource = "unknown";

    aCancelQuit.data = buttonPressed != 0;
  }

})();