Don't use the container to look up the store for drafts

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

@@ -2,6 +2,44 @@ import { setting } from 'discourse/lib/computed';
 import DiscourseURL from 'discourse/lib/url';
 import Quote from 'discourse/lib/quote';
 import Draft from 'discourse/models/draft';
+import Composer from 'discourse/models/composer';
+
+function loadDraft(store, opts) {
+  opts = opts || {};
+
+  let draft = opts.draft;
+  const draftKey = opts.draftKey;
+  const draftSequence = opts.draftSequence;
+
+  try {
+    if (draft && typeof draft === 'string') {
+      draft = JSON.parse(draft);
+    }
+  } catch (error) {
+    draft = null;
+    Draft.clear(draftKey, draftSequence);
+  }
+  if (draft && ((draft.title && draft.title !== '') || (draft.reply && draft.reply !== ''))) {
+    const composer = store.createRecord('composer');
+    composer.open({
+      draftKey,
+      draftSequence,
+      action: draft.action,
+      title: draft.title,
+      categoryId: draft.categoryId || opts.categoryId,
+      postId: draft.postId,
+      archetypeId: draft.archetypeId,
+      reply: draft.reply,
+      metaData: draft.metaData,
+      usernames: draft.usernames,
+      draft: true,
+      composerState: Composer.DRAFT,
+      composerTime: draft.composerTime,
+      typingTime: draft.typingTime
+    });
+    return composer;
+  }
+}
 
 export default Ember.Controller.extend({
   needs: ['modal', 'topic', 'composer-messages', 'application'],
@@ -438,7 +476,7 @@ export default Ember.Controller.extend({
   // Given a potential instance and options, set the model for this composer.
   _setModel(composerModel, opts) {
     if (opts.draft) {
-      composerModel = Discourse.Composer.loadDraft(opts);
+      composerModel = loadDraft(this.store, opts);
       if (composerModel) {
         composerModel.set('topic', opts.topic);
       }

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

@@ -690,47 +690,6 @@ const Composer = RestModel.extend({
 
 Composer.reopenClass({
 
-  open(opts) {
-    const composer = Discourse.__container__.lookup('store:main').createRecord('composer');
-    composer.open(opts);
-    return composer;
-  },
-
-  loadDraft(opts) {
-    opts = opts || {};
-
-    let draft = opts.draft;
-    const draftKey = opts.draftKey;
-    const draftSequence = opts.draftSequence;
-
-    try {
-      if (draft && typeof draft === 'string') {
-        draft = JSON.parse(draft);
-      }
-    } catch (error) {
-      draft = null;
-      Draft.clear(draftKey, draftSequence);
-    }
-    if (draft && ((draft.title && draft.title !== '') || (draft.reply && draft.reply !== ''))) {
-      return this.open({
-        draftKey,
-        draftSequence,
-        action: draft.action,
-        title: draft.title,
-        categoryId: draft.categoryId || opts.categoryId,
-        postId: draft.postId,
-        archetypeId: draft.archetypeId,
-        reply: draft.reply,
-        metaData: draft.metaData,
-        usernames: draft.usernames,
-        draft: true,
-        composerState: DRAFT,
-        composerTime: draft.composerTime,
-        typingTime: draft.typingTime
-      });
-    }
-  },
-
   // TODO: Replace with injection
   create(args) {
     args = args || {};