Add tests for dead help links. Fix some minor bugs. Show error when trying to modify a builtin group rather than failing silently.

common/modules/addons.jsm

@@ -229,9 +229,9 @@ var Addon = Class("Addon", {
             if (node.update && node.update !== callee)
                 node.update();
 
-        let event = this.document.createEvent("Events");
+        let event = this.list.document.createEvent("Events");
         event.initEvent("dactyl-commandupdate", true, false);
-        this.document.dispatchEvent(event);
+        this.list.document.dispatchEvent(event);
     }
 });
 
@@ -261,9 +261,9 @@ var AddonList = Class("AddonList", {
         this.ready = false;
 
         AddonManager.getAddonsByTypes(types, this.closure(function (addons) {
-            addons.forEach(this.closure.addAddon);
-            this.ready = true;
-            this.update();
+            this._addons = addons;
+            if (this.document)
+                this._init();
         }));
         AddonManager.addAddonListener(this);
     },
@@ -271,6 +271,12 @@ var AddonList = Class("AddonList", {
         AddonManager.removeAddonListener(this);
     },
 
+    _init: function _init() {
+        this._addons.forEach(this.closure.addAddon);
+        this.ready = true;
+        this.update();
+    },
+
     message: Class.memoize(function () {
 
         XML.ignoreWhitespace = true;
@@ -284,6 +290,9 @@ var AddonList = Class("AddonList", {
                         </tr>
                       </table>, this.document, this.nodes);
 
+        if (this._addons)
+            this._init();
+
         return this.nodes.list;
     }),
 

common/modules/contexts.jsm

@@ -463,6 +463,11 @@ var Contexts = Module("contexts", {
 
                 if (args.context)
                     args.context.group = group;
+
+                util.assert(!group.builtin ||
+                                !["-description", "-locations", "-nopersist"]
+                                    .some(function (arg) set.has(args.explicitOpts, arg)),
+                            "Cannot modify builtin group");
             },
             {
                 argCount: "?",

common/modules/javascript.jsm

@@ -73,8 +73,10 @@ var JavaScript = Module("javascript", {
 
         let seen = isinstance(obj, ["Sandbox"]) ? set(JavaScript.magicalNames) : {};
         let globals = values(toplevel && this.window === obj ? this.globalNames : []);
-        if (toplevel && "wrappedJSObject" in obj)
+
+        if (toplevel && isObject(obj) && "wrappedJSObject" in obj)
             yield "wrappedJSObject";
+
         for (let key in iter(globals, properties(obj, !toplevel, true)))
             if (!set.add(seen, key))
                 yield key;