FIX: Duplicate link shouldn't happen on edit

app/assets/javascripts/discourse/controllers/composer.js.es6

@@ -111,17 +111,19 @@ export default Ember.Controller.extend({
     },
 
     afterRefresh($preview) {
+
       const linkLookup = this.get('linkLookup');
       if (linkLookup) {
-        const $links = $('a[href]', $preview);
+        const post = this.get('model.post');
+        if (post && post.get('user_id') !== this.currentUser.id) { return; }
 
+        const $links = $('a[href]', $preview);
         $links.each((idx, l) => {
           const href = $(l).prop('href');
           if (href && href.length) {
-            const [warn, info] = linkLookup.check(href);
+            const [warn, info] = linkLookup.check(post, href);
 
             if (warn) {
-              console.log(info);
               const body = I18n.t('composer.duplicate_link', {
                 domain: info.domain,
                 username: info.username,
@@ -482,7 +484,7 @@ export default Ember.Controller.extend({
 
   // Given a potential instance and options, set the model for this composer.
   _setModel(composerModel, opts) {
-    this.set('linkList', null);
+    this.set('linkLookup', null);
 
     if (opts.draft) {
       composerModel = loadDraft(this.store, opts);

app/assets/javascripts/discourse/lib/link-lookup.js.es6

@@ -1,24 +1,29 @@
 const _warned = {};
 
+const NO_RESULT = [false, null];
+
 export default class LinkLookup {
 
   constructor(links) {
     this._links = links;
   }
 
-  check(href) {
-    if (_warned[href]) { return [false, null]; }
+  check(post, href) {
+    if (_warned[href]) { return NO_RESULT; }
 
-    const normalized = href.replace(/^https?:\/\//, '');
-    if (_warned[normalized]) { return [false, null]; }
+    const normalized = href.replace(/^https?:\/\//, '').replace(/\/$/, '');
+    if (_warned[normalized]) { return NO_RESULT; }
 
     const linkInfo = this._links[normalized];
     if (linkInfo) {
+      // Skip edits to the same URL
+      if (post && post.get('url') === linkInfo.post_url) { return NO_RESULT; }
+
       _warned[href] = true;
       _warned[normalized] = true;
       return [true, linkInfo];
     }
 
-    return [false, null];
+    return NO_RESULT;
   }
 };

app/controllers/composer_messages_controller.rb

@@ -8,7 +8,7 @@ class ComposerMessagesController < ApplicationController
     finder = ComposerMessagesFinder.new(current_user, params.slice(:composer_action, :topic_id, :post_id))
     json = { composer_messages: [finder.find].compact }
 
-    if params[:composer_action] == "reply" && params[:topic_id].present?
+    if params[:topic_id].present?
       topic = Topic.where(id: params[:topic_id]).first
       if guardian.can_see?(topic)
         json[:extras] = {duplicate_lookup: TopicLink.duplicate_lookup(topic)}

app/models/topic_link.rb

@@ -229,7 +229,7 @@ class TopicLink < ActiveRecord::Base
 
     lookup = {}
     results.each do |tl|
-      normalized = tl.url.downcase.sub(/^https?:\/\//, '')
+      normalized = tl.url.downcase.sub(/^https?:\/\//, '').sub(/\/$/, '')
       lookup[normalized] = { domain: tl.domain,
                              username: tl.post.user.username_lower,
                              post_url: tl.post.url,