wireprotoserver: define and use parse_qs from urllib The cgi module is deprecated since Python 2.6. Let's replace uses of it in wireprotoserver with a similar function from urllib. Differential Revision: https://phab.mercurial-scm.org/D2094

tests: add tests for sending recognized command before handshake Rounding out our test coverage for the SSH server. Differential Revision: https://phab.mercurial-scm.org/D2093

wireprotoserver: add version to SSH protocol names (API) We recently introduced version 2 of the SSH protocol. Like we did for the peer, we will need to differentiate version 1 and 2 of the server. So, we add version components to the advertised name of the protocol handler. Nothing in core looks for the old value. But an extension may. .. api:: SSH protocol handler now advertises its name internally as "ssh-v1" instead of "ssh." Differential Revision: https://phab.mercurial-scm.org/D2092

wireproto: introduce type for raw byte responses (API) Right now we simply return a str/bytes instance for simple responses. I want all wire protocol response types to be strongly typed. So let's invent and use a type for raw bytes responses. .. api:: Wire protocol command handlers now return a wireprototypes.bytesresponse instead of a raw bytes instance. Protocol handlers will continue handling bytes instances. However, any extensions wrapping wire protocol commands will need to handle the new type. Differential Revision: https://phab.mercurial-scm.org/D2089

wireprototypes: move wire protocol response types to new module We'll be introducing more types as part of wire protocol version 2. These types are shared between the command handling code (in wireproto.py) and the protocol/transport code in wireprotoserver.py. So they need to go in a new module to prevent a cycle. The types are aliased into the wireproto module, so API compatibility is preserved. Differential Revision: https://phab.mercurial-scm.org/D2088

wireprotoserver: move responsetype() out of http handler This is our last public attribute not part of the protocol interface! Differential Revision: https://phab.mercurial-scm.org/D2087

wireproto: remove unused proto argument from supportedcompengines (API) In theory, the protocol should be passed to this function. But the argument isn't being used and it is getting in the way of refactoring. So let's remove it. We can always add it back later if we need it again. Differential Revision: https://phab.mercurial-scm.org/D2086

wireprotoserver: rename getfile() to forwardpayload() (API) "file" can mean a lot of things. Let's rename the interface method to something more descriptive. While I was here, I moved the docs about the payload format to the implementation of the SSH protocol, because it was lying about what the HTTP payload looked like. Differential Revision: https://phab.mercurial-scm.org/D2085