FIX: Failed incoming emails could create empty topics

A failure condition is eliminated where a topic would be created, but post
creation would fail, leaving the forum with a topic without any posts.
By asking PostCreator to create the topic instead, inside of its
transaction, this failure condition is eliminated.

Additionally, attachments are restored to working status. Previously,
the attachment code would build up the post raw, but then drop it and
not do anything with the result (creating orphaned uploads). By actually
placing the raw value back in the options hash, it is included in the
created post.

lib/email/receiver.rb

@@ -94,7 +94,6 @@ module Email
       {type: :invalid, obj: nil}
     end
 
-    private
 
     def parse_body
       html = nil
@@ -168,37 +167,37 @@ module Email
 [/quote]"
     end
 
+    private
+
     def create_reply
-      create_post_with_attachments(email_log.user, @body, @email_log.topic_id, @email_log.post.post_number)
+      create_post_with_attachments(@email_log.user,
+                                   raw: @body,
+                                   topic_id: @email_log.topic_id,
+                                   reply_to_post_number: @email_log.post.post_number)
     end
 
     def create_new_topic
-      topic = TopicCreator.new(
-        @user,
-        Guardian.new(@user),
-        category: @category_id,
-        title: @message.subject,
-      ).create
-
-      post = create_post_with_attachments(@user, @body, topic.id)
+      post = create_post_with_attachments(@user,
+                                          raw: @body,
+                                          title: @message.subject,
+                                          category: @category_id)
 
       EmailLog.create(
         email_type: "topic_via_incoming_email",
-        to_address: @message.to.first,
-        topic_id: topic.id,
+        to_address: @message.from.first, # pick from address because we want the user's email
+        topic_id: post.topic.id,
         user_id: @user.id,
       )
 
       post
     end
 
-    def create_post_with_attachments(user, raw, topic_id, reply_to_post_number=nil)
+    def create_post_with_attachments(user, post_opts={})
       options = {
-        raw: raw,
-        topic_id: topic_id,
         cooking_options: { traditional_markdown_linebreaks: true },
-      }
-      options[:reply_to_post_number] = reply_to_post_number if reply_to_post_number
+      }.merge(post_opts)
+
+      raw = options[:raw]
 
       # deal with attachments
       @message.attachments.each do |attachment|
@@ -215,9 +214,10 @@ module Email
         ensure
           tmp.close!
         end
-
       end
 
+      options[:raw] = raw
+
       create_post(user, options)
     end
 
@@ -232,9 +232,11 @@ module Email
     def create_post(user, options)
       creator = PostCreator.new(user, options)
       post = creator.create
+
       if creator.errors.present?
         raise InvalidPost, creator.errors.full_messages.join("\n")
       end
+
       post
     end