Email-in topic_creator bug

Bug
1

Hello,

I set up pop polling using Gmail. Discourse fails to create new posts on some of the e-mails, not all.
I checked the logs and found the following error message and backtrace:

Unrecognized error type (NoMethodError: undefined method `>’ for nil:NilClass) when processing incoming email

Backtrace:
>   /var/www/discourse/lib/topic_creator.rb:161:in `setup_tags'
>   /var/www/discourse/lib/topic_creator.rb:37:in `create'
>   /var/www/discourse/lib/post_creator.rb:406:in `create_topic'
>   /var/www/discourse/lib/post_creator.rb:167:in `block in create'
>   /var/www/discourse/lib/post_creator.rb:331:in `block in transaction'
>   /var/www/discourse/vendor/bundle/ruby/2.5.0/gems/activerecord-5.2.0/lib/active_record/connection_adapters/abstract/database_statements.rb:254:in `block in transaction'
>   /var/www/discourse/vendor/bundle/ruby/2.5.0/gems/activerecord-5.2.0/lib/active_record/connection_adapters/abstract/transaction.rb:230:in `block in within_new_transaction'
>   /usr/local/lib/ruby/2.5.0/monitor.rb:226:in `mon_synchronize'
>   /var/www/discourse/vendor/bundle/ruby/2.5.0/gems/activerecord-5.2.0/lib/active_record/connection_adapters/abstract/transaction.rb:227:in `within_new_transaction'
>   /var/www/discourse/vendor/bundle/ruby/2.5.0/gems/activerecord-5.2.0/lib/active_record/connection_adapters/abstract/database_statements.rb:254:in `transaction'
>   /var/www/discourse/vendor/bundle/ruby/2.5.0/gems/activerecord-5.2.0/lib/active_record/transactions.rb:212:in `transaction'
>   /var/www/discourse/lib/post_creator.rb:330:in `transaction'
>   /var/www/discourse/lib/post_creator.rb:165:in `create'
>   /var/www/discourse/lib/new_post_manager.rb:204:in `perform_create_post'
>   /var/www/discourse/lib/new_post_manager.rb:178:in `perform'
>   /var/www/discourse/lib/email/receiver.rb:988:in `create_post'
>   /var/www/discourse/lib/email/receiver.rb:895:in `create_post_with_attachments'
>   /var/www/discourse/lib/email/receiver.rb:850:in `create_topic'
>   /var/www/discourse/lib/email/receiver.rb:596:in `process_destination'
>   /var/www/discourse/lib/email/receiver.rb:166:in `block in process_internal'
>   /var/www/discourse/lib/email/receiver.rb:164:in `yield'
>   /var/www/discourse/lib/email/receiver.rb:164:in `each'
>   /var/www/discourse/lib/email/receiver.rb:164:in `each'
>   /var/www/discourse/lib/email/receiver.rb:164:in `each'
>   /var/www/discourse/lib/email/receiver.rb:164:in `each'
>   /var/www/discourse/lib/email/receiver.rb:164:in `process_internal'
>   /var/www/discourse/lib/email/receiver.rb:74:in `block in process!'
>   /var/www/discourse/lib/distributed_mutex.rb:34:in `synchronize'
>   /var/www/discourse/lib/distributed_mutex.rb:5:in `synchronize'
>   /var/www/discourse/lib/email/receiver.rb:68:in `process!'
>   /var/www/discourse/lib/email/processor.rb:18:in `process!'
>   /var/www/discourse/lib/email/processor.rb:12:in `process!'
>   /var/www/discourse/app/jobs/scheduled/poll_mailbox.rb:25:in `process_popmail'
>   /var/www/discourse/app/jobs/scheduled/poll_mailbox.rb:43:in `block (2 levels) in poll_pop3'
>   /usr/local/lib/ruby/2.5.0/net/pop.rb:666:in `each'
>   /usr/local/lib/ruby/2.5.0/net/pop.rb:666:in `each_mail'
>   /var/www/discourse/app/jobs/scheduled/poll_mailbox.rb:42:in `block in poll_pop3'
>   /usr/local/lib/ruby/2.5.0/net/pop.rb:532:in `start'
>   /var/www/discourse/app/jobs/scheduled/poll_mailbox.rb:41:in `poll_pop3'
>   /var/www/discourse/app/jobs/scheduled/poll_mailbox.rb:16:in `execute'
>   /var/www/discourse/app/jobs/base.rb:137:in `block (2 levels) in perform'
>   /var/www/discourse/vendor/bundle/ruby/2.5.0/gems/rails_multisite-2.0.4/lib/rails_multisite/connection_management.rb:63:in `with_connection'
>   /var/www/discourse/app/jobs/base.rb:127:in `block in perform'
>   /var/www/discourse/app/jobs/base.rb:123:in `each'
>   /var/www/discourse/app/jobs/base.rb:123:in `perform'
>   /var/www/discourse/app/jobs/base.rb:185:in `perform'
>   /var/www/discourse/vendor/bundle/ruby/2.5.0/gems/mini_scheduler-0.8.1/lib/mini_scheduler/manager.rb:81:in `process_queue'
>   /var/www/discourse/vendor/bundle/ruby/2.5.0/gems/mini_scheduler-0.8.1/lib/mini_scheduler/manager.rb:29:in `block in initialize'

I tried changing /var/www/discourse/lib/topic_creator.rb line 161 to

if category && !category.nil? && category.present? && category.minimum_required_tags > 0

and restarted unicorn. But the problem persists. It still displays the same message.

2

It sounds like you’re seeing the same issue as here. Can you try following this workaround on the category you are trying to post in:

I will look at fixing this properly next week, as it should not be possible for it to break like this.

4 Likes
4

Yep, for now, that did the trick. Apologies for posting the same issue again, and thanks for the solution!

Best regards,
sizeof

1 Like
5

No worries, now we know that it wasn’t a one-off, so will be double-sure to get it fixed! :slight_smile:

2 Likes
6

Just an FYI.

When I opened the Settings tab the Minimum required tags field had no number. Then it clicked. I should’ve checked if category.minimum_required_tags is nil, not category. So changing it to

if category.present? && category.minimum_required_tags && !category.minimum_required_tags.nil? && category.minimum_required_tags > 0

seems to fix the issue. But this feels like a hack. I’m not sure why the field is missing a value and according to that the issue might be elsewhere. That field should have an integer value only. And I guess the extra check if it’s nil is not a bad thing since you can never trust user input :slight_smile:

2 Likes
7

Fixed by @maja :confetti_ball:

https://github.com/discourse/discourse/commit/4a8f21d38743a0a6b2a161889e335581248583b9

6 Likes