Post processing callbacks are run on invalid attachments.

[jhawthorn]

From the README

NOTE: Post-processing will not even start if the attachment is not valid according to the validations. Your callbacks and processors will only be called with valid attachments.

However in attachment.rb

instance.run_paperclip_callbacks(:post_process) do
  instance.run_paperclip_callbacks(:"#{name}_post_process") do
    if !@options[:check_validity_before_processing] || !instance.errors.any?
      post_process_styles(*style_args)
    end
  end
end

The check for validity happens inside the run_paperclip_callbacks blocks, so the callbacks are always run.

Reported by @karlentwistle in solidusio/solidus#2064

[karlentwistle]

I had a go at fixing this as you can see 🙈 I can only get the issue to bubble if I call instance.valid? which does actually return false and would circumvent the post processes for the invalid attachment but this breaks a lot of tests if called here https://github.com/karlentwistle/paperclip/commit/f1fa56b5d1206d80da4fcfc0ffb3bcf468517e7a instead of instance.errors.any?. However instance.errors.any? doesn't contain the relevant error unless instance.valid? is called.

[sidraval]

Looks like there's an open PR that will be merged, closing.

[ssinghi]

This has been fixed at https://github.com/kreeti/paperclip/commits/master.