Re: Clarify some handling about extension frame and unknown frame on HTTP/2

Hi Cory and Tatshuhiro,

Thanks for your detailed and clear explanation!
So the rule “never contains other frame in header blocks” had the higher priority than "drop unknown frame".


> Cory Benfield <cory@lukasa.co.uk> 於 2017年1月21日 下午9:50 寫道：
> 
> 
>> On 21 Jan 2017, at 08:22, Tatsuhiro Tsujikawa <tatsuhiro.t@gmail.com <mailto:tatsuhiro.t@gmail.com>> wrote:
>> 
>> ​My understanding is that unknown frame type must be ignored except for those which are received in the middle of header block.   The unknown frame type appearing in the middle of header block must be treated as connection error.
> 
> This is correct. A header block must always be a HEADERS frame, followed by zero or more CONTINUATION frames until one of these frames is marked with the END_HEADERS. If an unknown frame appears in that sequence, that violates the HEADERS rules, and so is a connection error.
> 
> Cory