Payment gets into unknown "processing" state

[tamagokun]

I need to manually process Paypal payments through an integration. This is how I am doing it

payment.settle!

Sometimes the payments transition to complete and sometimes they don't and get stuck in a processing state.

I thought that perhaps because Braintree was returning a settling response instead of a settled response that this was the cause. However that doesn't appear to be the case.

It seems like this line might be the culprit: https://github.com/spree-contrib/spree_braintree_vzero/blob/master/app/models/spree/payment/processing_decorator.rb#L41

If set_current_state is called, and the action is :settle, this method will just return the current_state passed into it, correct? Should I be doing payment.purchase! instead?