reply to first post === reply to topic

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

@@ -100,11 +100,16 @@ Discourse.QuoteButtonController = Discourse.Controller.extend({
     var post = this.get('post');
     var composerController = this.get('controllers.composer');
     var composerOpts = {
-      post: post,
       action: Discourse.Composer.REPLY,
       draftKey: this.get('post.topic.draft_key')
     };
 
+    if(post.get('post_number') === 1) {
+      composerOpts.topic = post.get("topic");
+    } else {
+      composerOpts.post = post;
+    }
+
     // If the composer is associated with a different post, we don't change it.
     var composerPost = composerController.get('content.post');
     if (composerPost && (composerPost.get('id') !== this.get('post.id'))) {