Register about:cfg

waterfox/browser/components/WaterfoxGlue.sys.mjs

@@ -16,6 +16,7 @@ ChromeUtils.defineESModuleGetters(lazy, {
   TabFeatures: 'resource:///modules/TabFeatures.sys.mjs',
   setTimeout: 'resource://gre/modules/Timer.sys.mjs',
   UICustomizations: 'resource:///modules/UICustomizations.sys.mjs',
+  AboutCfg: 'resource:///modules/AboutCfg.sys.mjs',
 })
 
 const WATERFOX_CUSTOMIZATIONS_PREF =
@@ -70,7 +71,10 @@ export const WaterfoxGlue = {
     // Observe browser shutdown
     Services.obs.addObserver(this, 'quit-application-granted')
     // Listen for addon events
-    this.addAddonListener()
+    this.addAddonListener();
+
+    // Register about:cfg
+    lazy.AboutCfg.init();
   },
 
   async _setPrefObservers() {

waterfox/browser/components/aboutcfg/AboutCfg.sys.mjs

@@ -0,0 +1,57 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+// https://github.com/earthlng/aboutconfig/blob/main/aboutcfg.jsm
+const registrar = Components.manager.QueryInterface(Components.interfaces.nsIComponentRegistrar);
+
+// generate a unique ID on every app launch. protection against the very unlikely possibility that a
+// future update adds a component with the same class ID, which would break the script.
+function generateFreeCID() {
+  let uuid = Components.ID(Services.uuid.generateUUID().toString());
+  // I can't tell whether generateUUID is guaranteed to produce a unique ID, or just a random ID.
+  // so I add this loop to regenerate it in the extremely unlikely (or potentially impossible)
+  // event that the UUID is already registered as a CID.
+  while (registrar.isCIDRegistered(uuid)) {
+    uuid = Components.ID(Services.uuid.generateUUID().toString());
+  }
+  return uuid;
+}
+
+function VintageAboutConfig() {}
+VintageAboutConfig.prototype = {
+  get uri() {
+    const urlString = 'chrome://browser/content/aboutcfg/aboutcfg.xhtml';
+    return this._uri || (this._uri = Services.io.newURI(urlString));
+  },
+  newChannel: function (_uri, loadInfo) {
+    const ch = Services.io.newChannelFromURIWithLoadInfo(this.uri, loadInfo);
+    ch.owner = Services.scriptSecurityManager.getSystemPrincipal();
+    return ch;
+  },
+  getURIFlags: function (_uri) {
+    return Components.interfaces.nsIAboutModule.ALLOW_SCRIPT | Components.interfaces.nsIAboutModule.IS_SECURE_CHROME_UI;
+  },
+  getChromeURI: function (_uri) {
+    return this.uri;
+  },
+  QueryInterface: ChromeUtils.generateQI(['nsIAboutModule']),
+};
+
+export const AboutCfg = {
+  init() {
+    const AboutModuleFactory = {
+      createInstance(aIID) {
+        return new VintageAboutConfig().QueryInterface(aIID);
+      },
+      QueryInterface: ChromeUtils.generateQI(['nsIFactory']),
+    };
+
+    registrar.registerFactory(
+      generateFreeCID(),
+      'about:cfg',
+      '@mozilla.org/network/protocol/about;1?what=cfg',
+      AboutModuleFactory
+    );
+  }
+}

waterfox/browser/components/aboutcfg/moz.build

@@ -4,4 +4,8 @@
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
+EXTRA_JS_MODULES += [
+    "AboutCfg.sys.mjs",
+]
+
 JAR_MANIFESTS += ["jar.mn"]