wireproto: crude support for version 2 HTTP peer As part of implementing the server-side bits of the wire protocol command handlers for version 2, we want a way to easily test those commands. Currently, we use the "httprequest" action of `hg debugwireproto`. But this requires explicitly specifying the HTTP request headers, low-level frame details, and the data structure to encode with CBOR. That's a lot of boilerplate and a lot of it can change as the wire protocol evolves. `hg debugwireproto` has a mechanism to issue commands via the peer interface. That is *much* easier to use and we prefer to test with that going forward. This commit implements enough parts of the peer API to send basic requests via the HTTP version 2 transport. The peer code is super hacky. Again, the goal is to facilitate server testing, not robustly implement a client. The client code will receive love at a later time. Differential Revision: https://phab.mercurial-scm.org/D3177

--- a/tests/test-http-protocol.t	Mon Mar 26 15:34:52 2018 -0700
+++ b/tests/test-http-protocol.t	Wed Mar 28 15:09:34 2018 -0700
@@ -179,7 +179,7 @@
   s>     Accept-Encoding: identity\r\n
   s>     accept: application/mercurial-0.1\r\n
   s>     host: $LOCALIP:$HGPORT\r\n (glob)
-  s>     user-agent: mercurial/proto-1.0 (Mercurial *)\r\n (glob)
+  s>     user-agent: Mercurial debugwireproto\r\n
   s>     \r\n
   s> makefile('rb', None)
   s>     HTTP/1.1 200 Script output follows\r\n
@@ -197,7 +197,7 @@
   s>     x-hgproto-1: 0.1 0.2 comp=$USUAL_COMPRESSIONS$\r\n
   s>     accept: application/mercurial-0.1\r\n
   s>     host: $LOCALIP:$HGPORT\r\n (glob)
-  s>     user-agent: mercurial/proto-1.0 (Mercurial *)\r\n (glob)
+  s>     user-agent: Mercurial debugwireproto\r\n
   s>     \r\n
   s> makefile('rb', None)
   s>     HTTP/1.1 200 Script output follows\r\n