Cleaned up TopicUserSpec, introduces clearing of pinned topics

app/assets/javascripts/discourse/controllers/topic_controller.js

@@ -255,6 +255,15 @@ Discourse.TopicController = Discourse.ObjectController.extend({
     this.get('content').toggleStar();
   },
 
+  /**
+    Clears the pin from a topic for the currentUser
+
+    @method clearPin
+  **/
+  clearPin: function() {
+    this.get('content').clearPin();
+  },
+
   // Receive notifications for this topic
   subscribe: function() {
     var bus,

app/assets/javascripts/discourse/models/topic.js

@@ -329,6 +329,27 @@ Discourse.Topic = Discourse.Model.extend({
     });
   },
 
+  /**
+    Clears the pin from a topic for the currentUser
+
+    @method clearPin
+  **/
+  clearPin: function() {
+
+    var topic = this;
+
+    // Clear the pin optimistically from the object
+    topic.set('pinned', false);
+
+    $.ajax("/t/" + this.get('id') + "/clear-pin", {
+      type: 'PUT',
+      error: function() {
+        // On error, put the pin back
+        topic.set('pinned', true);
+      }
+    });
+  },
+
   // Is the reply to a post directly below it?
   isReplyDirectlyBelow: function(post) {
     var postBelow, posts;

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

@@ -68,6 +68,30 @@ Discourse.TopicFooterButtonsView = Ember.ContainerView.extend({
             buffer.push("<i class='icon icon-share'></i>");
           }
         }));
+
+        // Add our clear pin button
+        this.addObject(Discourse.ButtonView.createWithMixins({
+          textKey: 'topic.clear_pin.title',
+          helpKey: 'topic.clear_pin.help',
+          classNameBindings: ['unpinned'],
+
+          // Hide the button if it becomes unpinned
+          unpinned: function() {
+            // When not logged in don't show the button
+            if (!Discourse.get('currentUser')) return 'hidden'
+
+            return this.get('controller.pinned') ? null : 'hidden';
+          }.property('controller.pinned'),
+
+          click: function(buffer) {
+            this.get('controller').clearPin();
+          },
+
+          renderIcon: function(buffer) {
+            buffer.push("<i class='icon icon-pushpin'></i>");
+          }
+        }));
+
       }
 
       this.addObject(Discourse.ButtonView.createWithMixins({