after a production deploy, we noticed some images (delivered by send_file) stopped working, seemingly after a short period of activity.
After some investigation we discovered the cache (page_cache) for these images was being populated with the following string:
This caused many headaches, and we eventually deployed a fix that simply set :stream => false on the call.
The fact that this was surprising, motivated me to write the patch attached to the ticket.
Have a look, let me know what you think.