Preserve the flash after the action to avoid double-sweeping.
Preserve the flash after the action to avoid double-sweeping.

We also reference the flash by default when a template is streamed,
ensuring the flash is swept before the headers are output.

This has the side-effect that the flash is swept when a template is
streamed, even if not referenced in the controller or view. Usually,
this is not a problem, as flash messages are often rendered in the
layout, ensuring a sweep anyway.

If this is undesirable, you may disable this behavior by adding this
to a file in config/initializers:

    TemplateStreaming.configure(:autosweep_flash => false)

However, you'll have to ensure the flash is referenced during the
necessary actions yourself, or it won't be swept.

oggy/template_streaming