HTTP/2 and non-authoritative pushes

Secondary Certs issue #1088 leads back to an interesting bit in RFC7540.  Section 8.2 says:


   The server MUST include a value in the ":authority" pseudo-header

   field for which the server is authoritative (see Section 10.1<https://tools.ietf.org/html/rfc7540#section-10.1>).  A

   client MUST treat a PUSH_PROMISE for which the server is not

   authoritative as a stream error (Section 5.4.2<https://tools.ietf.org/html/rfc7540#section-5.4.2>) of type

   PROTOCOL_ERROR.

Note that it doesn't explicitly say which stream should be treated as being in error.  The simplest reading, since it's an invalid PUSH_PROMISE, would be the stream on which the PUSH_PROMISE was sent.  However, the server and the client might not have the same view of what origins the server is authoritative for, for various reasons.  Given that, blowing up the parent request because of an invalid PUSH_PROMISE seems completely unreasonable as a response.  Should this indicate that it's a stream error on the promised stream?

(In Secondary Certs, the draft currently requires that the server have sent the certificate for the origin it wants to push for prior to pushing content, and violation of that is a connection error.  That doubly seems excessive, and I'll change that in a PR shortly.)