Re: Server Push Error Codes

I'm not real enthusiastic about push_is_cached.. it specifically leaks a
tracker. Admittedly its pretty easy to infer this anyway but I'd look
harder at it before codifying

as for push_unauthoritative, that's already a protocol error. I'm not sure
we need fine grained feedback to tune algorithms etc with.. you're just not
allowed to do that so it should be rare. I'm not opposed though.

I would be interested in both CONTENT_TYPE_NOT_SUPPORTED _and_
CONTENT_ENCODING_NOT_SUPPORTED .. I think brotli and webp are the
exemplars. CT could be hard to figure out, but might be worth special
casing the obvious stuff.