feat: fixes exception due to unread bytes in stream

sanic/server.py

@@ -416,12 +416,13 @@ async def body_append(self, body):
     async def stream_append(self):
         while self._body_chunks:
             body = self._body_chunks.popleft()
-            if self.request.stream.is_full():
-                self.transport.pause_reading()
-                await self.request.stream.put(body)
-                self.transport.resume_reading()
-            else:
-                await self.request.stream.put(body)
+            if self.request:
+                if self.request.stream.is_full():
+                    self.transport.pause_reading()
+                    await self.request.stream.put(body)
+                    self.transport.resume_reading()
+                else:
+                    await self.request.stream.put(body)
 
     def on_message_complete(self):
         # Entire request (headers and whole body) is received.

tests/test_request_stream.py

@@ -1,11 +1,13 @@
 import pytest
+import asyncio
 
 from sanic.blueprints import Blueprint
 from sanic.exceptions import HeaderExpectationFailed
 from sanic.request import StreamBuffer
 from sanic.response import json, stream, text
 from sanic.views import CompositionView, HTTPMethodView
 from sanic.views import stream as stream_decorator
+from sanic.server import HttpProtocol
 
 
 data = "abc" * 1_000_000
@@ -336,6 +338,20 @@ async def post(request, id):
     assert response.status == 405
     assert "Method GET not allowed for URL /post/random_id" in response.text
 
+@pytest.mark.asyncio
+async def test_request_stream_unread(app):
+    """ensure no error is raised when leaving unread bytes in byte-buffer"""
+
+    err = None
+    protocol = HttpProtocol(loop=asyncio.get_event_loop(), app=app)
+    try:
+        protocol.request = None
+        protocol._body_chunks.append('this is a test')
+        await protocol.stream_append()
+    except AttributeError as e:
+        err = e
+
+    assert err is None and not protocol._body_chunks
 
 def test_request_stream_blueprint(app):
     """for self.is_request_stream = True"""