Work around some conceivable race conditions in one of my least favorite commits ever.

common/content/commandline.js

@@ -255,16 +255,25 @@ var CommandWidgets = Class("CommandWidgets", {
     commandbar: Class.memoize(function () ({ group: "Cmd" })),
     statusbar: Class.memoize(function ()  ({ group: "Status" })),
 
-    _whenReady: function _whenReady(name, id) {
+    _ready: function _ready(elem) {
+        return elem.contentDocument.documentURI === elem.getAttribute("src") &&
+               ["viewable", "complete"].indexOf(elem.contentDocument.readyState) >= 0;
+    },
+
+    _whenReady: function _whenReady(id) {
         let elem = document.getElementById(id);
 
-        util.waitFor(function () elem.contentDocument.documentURI === elem.getAttribute("src") &&
+        util.waitFor(bind(this._ready, this, elem));
-               ["viewable", "complete"].indexOf(elem.contentDocument.readyState) >= 0);
 
         return elem;
     },
 
-    completionList: Class.memoize(function () this._whenReady("completionList", "dactyl-completions"), true),
+    completionList: Class.memoize(function () {
+        let elem = document.getElementById(elem);
+        while (!this._ready(elem))
+            yield 10;
+        yield elem;
+    }, true),
 
     completionContainer: Class.memoize(function () this.completionList.parentNode),
 
@@ -279,11 +288,14 @@ var CommandWidgets = Class("CommandWidgets", {
     }),
 
     multilineOutput: Class.memoize(function () {
-        let elem = this._whenReady("multilineOutput", "dactyl-multiline-output");
+        let elem = document.getElementById("dactyl-multiline-output");
+        while (!this._ready(elem))
+            yield 10;
+
         elem.contentWindow.addEventListener("unload", function (event) { event.preventDefault(); }, true);
         elem.contentDocument.documentElement.id = "dactyl-multiline-output-top";
         elem.contentDocument.body.id = "dactyl-multiline-output-content";
-        return elem;
+        yield elem;
     }, true),
 
     multilineInput: Class.memoize(function () document.getElementById("dactyl-multiline-input")),
@@ -569,7 +581,7 @@ var CommandLine = Module("commandline", {
     get completionList() {
         let node = this.widgets.active.commandline;
         if (!node.completionList) {
-            let elem = this.widgets._whenReady("completionList", "dactyl-completions-" + node.id);
+            let elem = this.widgets._whenReady("dactyl-completions-" + node.id);
             node.completionList = ItemList(elem.id);
         }
         return node.completionList;

common/modules/base.jsm

@@ -205,7 +205,7 @@ defineModule("base", {
     exports: [
         "ErrorBase", "Cc", "Ci", "Class", "Cr", "Cu", "Module", "JSMLoader", "Object", "Runnable",
         "Struct", "StructBase", "Timer", "UTF8", "XPCOM", "XPCOMUtils", "XPCSafeJSObjectWrapper",
-        "array", "call", "callable", "ctypes", "curry", "debuggerProperties", "defineModule",
+        "array", "bind", "call", "callable", "ctypes", "curry", "debuggerProperties", "defineModule",
         "deprecated", "endModule", "forEach", "isArray", "isGenerator", "isinstance", "isObject",
         "isString", "isSubclass", "iter", "iterAll", "keys", "memoize", "octal", "properties",
         "require", "set", "update", "values", "withCallerGlobal"
@@ -580,6 +580,14 @@ function curry(fn, length, self, acc) {
     };
 }
 
+if (curry.bind)
+    var bind = function bind(func) func.bind.apply(func, Array.slice(arguments, bind.length));
+else
+    var bind = function bind(func, self) {
+        let args = Array.slice(arguments, bind.length);
+        return function bound() func.apply(self, args.concat(Array.slice(arguments)));
+    };
+
 let sandbox = Cu.Sandbox(this);
 sandbox.__proto__ = this;
 /**
@@ -774,26 +782,37 @@ Class.memoize = function memoize(getter, wait)
         enumerable: true,
         init: function (key) {
             let done = false;
-            let prop = { configurable: true, enumerable: true, value: null, writable: true };
-            if (wait)
-                prop = {
-                    configurable: true, enumerable: false,
-                    get: function get() {
-                        util.waitFor(function () done);
-                        return this[key];
-                    }
-                }
 
-            this.get = function replace() {
+            if (wait)
-                let obj = this.instance || this;
+                this.get = function replace() {
-                Object.defineProperty(obj, key, prop);
+                    let obj = this.instance || this;
-                try {
+                    Object.defineProperty(obj, key,  {
+                        configurable: true, enumerable: false,
+                        get: function get() {
+                            util.waitFor(function () done);
+                            return this[key];
+                        }
+                    });
+
+                    util.yieldable(function () {
+                        let wait;
+                        for (var res in getter.call(obj)) {
+                            if (wait !== undefined)
+                                yield wait;
+                            wait = res;
+                        }
+                        Class.replaceProperty(obj, key, res);
+                        done = true;
+                    })();
+
+                    return this[key];
+                };
+            else
+                this.get = function replace() {
+                    let obj = this.instance || this;
+                    Class.replaceProperty(obj, key, null);
                     return Class.replaceProperty(obj, key, getter.call(this, key));
-                }
+                };
-                finally {
-                    done = true;
-                }
-            }
 
             this.set = function replace(val) Class.replaceProperty(this.instance || this, val);
         }

common/modules/config.jsm

@@ -56,17 +56,18 @@ var ConfigBase = Class("ConfigBase", {
     get addonID() this.name + "@dactyl.googlecode.com",
     addon: Class.memoize(function () {
         let addon;
-        util.waitFor(function () {
+        do {
             addon = services.fuel.storage.get("dactyl.bootstrap", {}).addon;
-            if (addon && !addon.getResourceURI)
+            if (addon && !addon.getResourceURI) {
                 util.reportError(Error("Don't have add-on yet"));
-
+                yield 10;
-            return !addon || addon.getResourceURI;
+            }
-        });
+        }
+        while (addon && !addon.getResourceURI);
 
         if (!addon)
             addon = require("addons").AddonManager.getAddonByID(this.addonID);
-        return addon;
+        yield addon;
     }, true),
 
     /**