FIX: Allow to change ownership on deleted users' posts

app/assets/javascripts/discourse/controllers/change-owner.js.es6

@@ -1,14 +1,15 @@
 import Presence from 'discourse/mixins/presence';
 import SelectedPostsCount from 'discourse/mixins/selected-posts-count';
 import ModalFunctionality from 'discourse/mixins/modal-functionality';
-import ObjectController from 'discourse/controllers/object';
 
 // Modal related to changing the ownership of posts
-export default ObjectController.extend(Presence, SelectedPostsCount, ModalFunctionality, {
+export default Ember.Controller.extend(Presence, SelectedPostsCount, ModalFunctionality, {
   needs: ['topic'],
 
   topicController: Em.computed.alias('controllers.topic'),
   selectedPosts: Em.computed.alias('topicController.selectedPosts'),
+  saving: false,
+  new_user: null,
 
   buttonDisabled: function() {
     if (this.get('saving')) return true;
@@ -38,7 +39,7 @@ export default ObjectController.extend(Presence, SelectedPostsCount, ModalFuncti
             username: this.get('new_user')
           };
 
-      Discourse.Topic.changeOwners(this.get('id'), saveOpts).then(function(result) {
+      Discourse.Topic.changeOwners(this.get('topicController.model.id'), saveOpts).then(function(result) {
         // success
         self.send('closeModal');
         self.get('topicController').send('toggleMultiSelect');

app/models/post.rb

@@ -400,7 +400,7 @@ class Post < ActiveRecord::Base
     return if user_id == new_user.id
 
     edit_reason = I18n.t('change_owner.post_revision_text',
-      old_user: self.user.username_lower,
+      old_user: (self.user.username_lower rescue nil) || I18n.t('change_owner.deleted_user'),
       new_user: new_user.username_lower
     )
 

app/services/post_owner_changer.rb

@@ -14,6 +14,12 @@ class PostOwnerChanger
       @post_ids.each do |post_id|
         post = Post.with_deleted.find(post_id)
         @topic.user = @new_owner if post.is_first_post?
+
+        if post.user == nil
+          post.recover!
+          @topic.recover! if post.is_first_post?
+        end
+        post.topic = @topic
         post.set_owner(@new_owner, @acting_user)
       end