Make HTTP connections start in IDLE stage, avoiding delays and error messages (#2268)

* Make all new connections start in IDLE stage, and switch to REQUEST stage only once any bytes are received from client. This makes new connections without any request obey keepalive timeout rather than request timeout like they currently do.

* Revert typo

* Remove request timeout endpoint test which is no longer working (still tested by mocking). Fix mock timeout test setup.

Co-authored-by: L. Karkkainen <tronic@users.noreply.github.com>

sanic/http.py

@@ -105,7 +105,6 @@ class Http(metaclass=TouchUpMeta):
         self.keep_alive = True
         self.stage: Stage = Stage.IDLE
         self.dispatch = self.protocol.app.dispatch
-        self.init_for_request()
 
     def init_for_request(self):
         """Init/reset all per-request variables."""
@@ -129,14 +128,20 @@ class Http(metaclass=TouchUpMeta):
         """
         HTTP 1.1 connection handler
         """
-        while True:  # As long as connection stays keep-alive
+        # Handle requests while the connection stays reusable
+        while self.keep_alive and self.stage is Stage.IDLE:
+            self.init_for_request()
+            # Wait for incoming bytes (in IDLE stage)
+            if not self.recv_buffer:
+                await self._receive_more()
+            self.stage = Stage.REQUEST
             try:
                 # Receive and handle a request
-                self.stage = Stage.REQUEST
                 self.response_func = self.http1_response_header
 
                 await self.http1_request_header()
 
+                self.stage = Stage.HANDLER
                 self.request.conn_info = self.protocol.conn_info
                 await self.protocol.request_handler(self.request)
 
@@ -187,16 +192,6 @@ class Http(metaclass=TouchUpMeta):
                 if self.response:
                     self.response.stream = None
 
-            # Exit and disconnect if no more requests can be taken
-            if self.stage is not Stage.IDLE or not self.keep_alive:
-                break
-
-            self.init_for_request()
-
-            # Wait for the next request
-            if not self.recv_buffer:
-                await self._receive_more()
-
     async def http1_request_header(self):  # no cov
         """
         Receive and parse request header into self.request.
@@ -299,7 +294,6 @@ class Http(metaclass=TouchUpMeta):
 
         # Remove header and its trailing CRLF
         del buf[: pos + 4]
-        self.stage = Stage.HANDLER
         self.request, request.stream = request, self
         self.protocol.state["requests_count"] += 1