From 4963d4d624145f7131c0f10584940a6d36970230 Mon Sep 17 00:00:00 2001
From: Robin Ward <robin.ward@gmail.com>
Date: Fri, 20 May 2016 12:13:10 -0400
Subject: [PATCH] UX: Don't animate timeline when first entering a topic

---
 .../discourse/initializers/live-development.js.es6          | 6 ++++++
 .../javascripts/discourse/widgets/topic-timeline.js.es6     | 5 +++--
 2 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/app/assets/javascripts/discourse/initializers/live-development.js.es6 b/app/assets/javascripts/discourse/initializers/live-development.js.es6
index a7318b1a794..a3c8afa51a3 100644
--- a/app/assets/javascripts/discourse/initializers/live-development.js.es6
+++ b/app/assets/javascripts/discourse/initializers/live-development.js.es6
@@ -1,4 +1,5 @@
 import loadScript from 'discourse/lib/load-script';
+import DiscourseURL from 'discourse/lib/url';
 
 //  Use the message bus for live reloading of components for faster development.
 export default {
@@ -30,6 +31,11 @@ export default {
       });
     });
 
+    // Useful to export this for debugging purposes
+    if (Discourse.Environment === 'development' && !Ember.testing) {
+      window.DiscourseURL = DiscourseURL;
+    }
+
     // Observe file changes
     messageBus.subscribe("/file-change", function(data) {
       if (Handlebars.compile && !Ember.TEMPLATES.empty) {
diff --git a/app/assets/javascripts/discourse/widgets/topic-timeline.js.es6 b/app/assets/javascripts/discourse/widgets/topic-timeline.js.es6
index 590601138fa..c05b5f57081 100644
--- a/app/assets/javascripts/discourse/widgets/topic-timeline.js.es6
+++ b/app/assets/javascripts/discourse/widgets/topic-timeline.js.es6
@@ -83,7 +83,7 @@ createWidget('timeline-scrollarea', {
   },
 
   defaultState() {
-    return { percentage: 0, scrolledPost: 1 };
+    return { percentage: null, scrolledPost: 1 };
   },
 
   position() {
@@ -124,6 +124,8 @@ createWidget('timeline-scrollarea', {
 
     state.scrolledPost = position.current;
     const percentage = state.percentage;
+    if (percentage === null) { return; }
+
     const before = SCROLLAREA_REMAINING * percentage;
     const after = (SCROLLAREA_HEIGHT - before) - SCROLLER_HEIGHT;
 
@@ -133,7 +135,6 @@ createWidget('timeline-scrollarea', {
       this.attach('timeline-padding', { height: after })
     ];
 
-
     if (position.lastRead && position.lastRead < attrs.topic.posts_count) {
       const lastReadTop = Math.round(position.lastReadPercentage * SCROLLAREA_HEIGHT);
       if (lastReadTop > (before + SCROLLER_HEIGHT)) {