FIX: Regression where a topic rollback would not properly report errors to the client.

lib/post_creator.rb

@@ -131,8 +131,15 @@ class PostCreator
   def setup_topic
     if @opts[:topic_id].blank?
       topic_creator = TopicCreator.new(@user, guardian, @opts)
+
+      begin
         topic = topic_creator.create
         @errors = topic_creator.errors
+      rescue ActiveRecord::Rollback => ex
+        # In the event of a rollback, grab the errors from the topic
+        @errors = topic_creator.errors
+        raise ex
+      end
 
       @new_topic = true
     else

spec/components/post_creator_spec.rb

@@ -26,6 +26,18 @@ describe PostCreator do
       lambda { creator.create }.should raise_error(Discourse::InvalidAccess)
     end
 
+
+    context "invalid title" do
+
+      let(:creator_invalid_title) { PostCreator.new(user, basic_topic_params.merge(title: 'a')) }
+
+      it "has errors" do
+        creator_invalid_title.create
+        expect(creator_invalid_title.errors).to be_present
+      end
+
+    end
+
     context 'success' do
 
       it "doesn't return true for spam" do