Fixes #264 - replaceState was wonky

app/assets/javascripts/discourse/components/url.js

@@ -13,6 +13,18 @@ Discourse.URL = {
   // Used for matching a /more URL
   MORE_REGEXP: /\/more$/,
 
+  /**
+    @private
+
+    Get a handle on the application's router. Note that currently it uses `__container__` which is not
+    advised but there is no other way to access the router.
+
+    @method router
+  **/
+  router: function(path) {
+    return Discourse.__container__.lookup('router:main');
+  },
+
   /**
     Browser aware replaceState. Will only be invoked if the browser supports it.
 
@@ -20,12 +32,19 @@ Discourse.URL = {
     @param {String} path The path we are replacing our history state with.
   **/
   replaceState: function(path) {
+
     if (window.history &&
         window.history.pushState &&
         window.history.replaceState &&
         !navigator.userAgent.match(/((iPod|iPhone|iPad).+\bOS\s+[1-4]|WebApps\/.+CFNetwork)/) &&
         (window.location.pathname !== path)) {
-        return history.replaceState({ path: path }, null, path);
+
+        // Always use replaceState in the next runloop to prevent weird routes changing
+        // while URLs are loading. For example, while a topic loads it sets `currentPost`
+        // which triggers a replaceState even though the topic hasn't fully loaded yet!
+        Em.run.next(function() {
+          Discourse.URL.router().get('location').replaceURL(path);
+        });
     }
   },
 
@@ -36,9 +55,6 @@ Discourse.URL = {
     It contains the logic necessary to route within a topic using replaceState to
     keep the history intact.
 
-    Note that currently it uses `__container__` which is not advised
-    but there is no other way to access the router.
-
     @method routeTo
     @param {String} path The path we are routing to.
   **/
@@ -71,13 +87,13 @@ Discourse.URL = {
     }
 
     // If we transition from a /more path, scroll to the top
-    if (this.MORE_REGEXP.exec(oldPath) && (!this.MORE_REGEXP.exec(path))) {
+    if (this.MORE_REGEXP.exec(oldPath) && (oldPath.indexOf(path) === 0)) {
       window.scrollTo(0, 0);
     }
 
     // Be wary of looking up the router. In this case, we have links in our
     // HTML, say form compiled markdown posts, that need to be routed.
-    var router = Discourse.__container__.lookup('router:main');
+    var router = this.router();
     router.router.updateURL(path);
     return router.handleURL(path);
   }

app/assets/javascripts/discourse/routes/discourse_location.js

@@ -1,8 +1,7 @@
 /*global historyState:true */
-(function() {
+
 /**
-  @module ember
+@module Discourse
-  @submodule ember-routing
 */
 
 var get = Ember.get, set = Ember.set;
@@ -13,7 +12,7 @@
   `history.pushState` API.
 
   @class DiscourseLocation
-    @namespace Ember
+  @namespace Discourse
   @extends Ember.Object
 */
 Ember.DiscourseLocation = Ember.Object.extend({
@@ -190,5 +189,3 @@
 });
 
 Ember.Location.registerImplementation('discourse_location', Ember.DiscourseLocation);
-
-})(this);

app/assets/javascripts/discourse/views/topic_view.js

@@ -69,14 +69,16 @@ Discourse.TopicView = Discourse.View.extend(Discourse.Scrolling, {
   }).observes('topic.highest_post_number'),
 
   currentPostChanged: (function() {
-    var current, postUrl, topic;
+    var current = this.get('controller.currentPost');
-    current = this.get('controller.currentPost');
+
-    topic = this.get('topic');
+    var topic = this.get('topic');
     if (!(current && topic)) return;
+
     if (current > (this.get('maxPost') || 0)) {
       this.set('maxPost', current);
     }
-    postUrl = topic.get('url');
+
+    var postUrl = topic.get('url');
     if (current > 1) {
       postUrl += "/" + current;
     } else {