Add tests for parsing chunked data split before or in the final CRLF

PR aio-libs#4651 by @JustAnotherArchivist

This change adds tests that demonstrate the failures described in aio-libs#4630.
They are marked as xfail so that they don't affect the CI status.
Once the issue is fixed, they'll reported as XPASS and pytest will fail,
which would be a signal that it's time to remove the xfail markers
keeping the contents of the tests to prevent regressions.

(ref: https://pganssle-talks.github.io/xfail-lightning)


Co-Authored-By: Sviatoslav Sydorenko <wk.cvs.github@sydorenko.org.ua>

tests/test_http_parser.py

@@ -826,6 +826,55 @@ async def test_parse_chunked_payload_size_error(self, stream) -> None:
         assert isinstance(out.exception(),
                           http_exceptions.TransferEncodingError)
 
+    @pytest.mark.xfail(
+        reason="see https://github.com/aio-libs/aiohttp/issues/4630"
+    )
+    async def test_parse_chunked_payload_split_end(self, protocol) -> None:
+        out = aiohttp.StreamReader(protocol, loop=None)
+        p = HttpPayloadParser(out, chunked=True)
+        p.feed_data(b'4\r\nasdf\r\n0\r\n')
+        p.feed_data(b'\r\n')
+
+        assert out.is_eof()
+        assert b'asdf' == b''.join(out._buffer)
+
+    @pytest.mark.xfail(
+        reason="see https://github.com/aio-libs/aiohttp/issues/4630"
+    )
+    async def test_parse_chunked_payload_split_end2(self, protocol) -> None:
+        out = aiohttp.StreamReader(protocol, loop=None)
+        p = HttpPayloadParser(out, chunked=True)
+        p.feed_data(b'4\r\nasdf\r\n0\r\n\r')
+        p.feed_data(b'\n')
+
+        assert out.is_eof()
+        assert b'asdf' == b''.join(out._buffer)
+
+    async def test_parse_chunked_payload_split_end_trailers(self,
+                                                            protocol) -> None:
+        out = aiohttp.StreamReader(protocol, loop=None)
+        p = HttpPayloadParser(out, chunked=True)
+        p.feed_data(b'4\r\nasdf\r\n0\r\n')
+        p.feed_data(b'Content-MD5: 912ec803b2ce49e4a541068d495ab570\r\n')
+        p.feed_data(b'\r\n')
+
+        assert out.is_eof()
+        assert b'asdf' == b''.join(out._buffer)
+
+    @pytest.mark.xfail(
+        reason="see https://github.com/aio-libs/aiohttp/issues/4630"
+    )
+    async def test_parse_chunked_payload_split_end_trailers2(self,
+                                                             protocol) -> None:
+        out = aiohttp.StreamReader(protocol, loop=None)
+        p = HttpPayloadParser(out, chunked=True)
+        p.feed_data(b'4\r\nasdf\r\n0\r\n')
+        p.feed_data(b'Content-MD5: 912ec803b2ce49e4a541068d495ab570\r\n\r')
+        p.feed_data(b'\n')
+
+        assert out.is_eof()
+        assert b'asdf' == b''.join(out._buffer)
+
     async def test_http_payload_parser_length(self, stream) -> None:
         out = aiohttp.FlowControlDataQueue(stream,
                                            loop=asyncio.get_event_loop())