I posted this to the talk mailing list but got no response, not sure if this list is more suitable.
As the subject suggests, I’m not sure if this is a bug or a feature.
If I have an action that sets something in the flash and redirects to an action (to pre-empt the “flash.now” responses) that renders something but does not touch the flash at all then the values will remain in the flash for following requests to pick up. This could potentially be an infinite number of requests later if none of the requests in between touch the flash.
Touching the flash in anyway (even without using it) will produce the behaviour I expect of the flash being cleared in the request following the redirect and so no further requests being able to access it. This means I can use an after_action or similar to ensure it is always loaded and get the behaviour I expect.
Is the current behaviour expected?
If it is, I have a work around and hopefully this will exist on Google for other people who expect it to work as I do. If it isn’t, I’m happy to look into it and create a pull request.