Try fixing ThreadResolveWorker calls (#3599)

* Try fixing ThreadResolveWorker calls

From my understanding of ActiveRecord, a transaction is commited as soon as
the exit of the outmost ActiveRecord.transaction block. However, inner
transaction blocks will exit without the transaction being commited.

In this case, ThreadResolveWorker were fired *within* a transaction block,
so moving the call out of it should do the trick. However, this is somewhat
fragile, as this whole codepath could be called within yet another transaction.

* Set status thread within the transaction block if it is immediately available from database

app/services/process_feed_service.rb

@@ -69,9 +69,16 @@ class ProcessFeedService < BaseService
           end
         end
 
+        status.thread = find_status(thread(@xml).first) if thread?(@xml)
+
         status.save!
       end
 
+      if thread?(@xml) && status.thread.nil?
+        Rails.logger.debug "Trying to attach #{status.id} (#{id(@xml)}) to #{thread(@xml).first}"
+        ThreadResolveWorker.perform_async(status.id, thread(@xml).second)
+      end
+
       notify_about_mentions!(status) unless status.reblog?
       notify_about_reblog!(status) if status.reblog? && status.reblog.account.local?
 
@@ -154,11 +161,6 @@ class ProcessFeedService < BaseService
         conversation: find_or_create_conversation(entry)
       )
 
-      if thread?(entry)
-        Rails.logger.debug "Trying to attach #{status.id} (#{id(entry)}) to #{thread(entry).first}"
-        status.thread = find_or_resolve_status(status, *thread(entry))
-      end
-
       mentions_from_xml(status, entry)
       hashtags_from_xml(status, entry)
       media_from_xml(status, entry)
@@ -166,14 +168,6 @@ class ProcessFeedService < BaseService
       [status, true]
     end
 
-    def find_or_resolve_status(parent, uri, url)
-      status = find_status(uri)
-
-      ThreadResolveWorker.perform_async(parent.id, url) if status.nil?
-
-      status
-    end
-
     def find_or_create_conversation(xml)
       uri = xml.at_xpath('./ostatus:conversation', ostatus: TagManager::OS_XMLNS)&.attribute('ref')&.content
       return if uri.nil?