(If this gets the thumbs up, I'll be happy to do the work:-) In testing new code, it's often helpful to simulate different browser requests, and responses.
For handlers and filters, mod_headers enables us to set up testcases very easily, with the Header and (especially) RequestHeader directives. But that's in a fixups hook, so it's no use for any hooks running in earlier phases of a request. My proposal is to introduce an additional DEBUG keyword to the Header and RequestHeader directives. Headers marked as DEBUG will be set in post_read_request, so they are available to other modules. Without DEBUG, it will default to current (fixups) behaviour. Of course, DEBUG won't work with conditional (Request)Header directives. In addition to documenting this, attempts to do so will log a warning. -- Nick Kew
