tests: Reproducer for #341

Signed-off-by: Jakub Jelen <[email protected]>

Author: Jakuje

tests/unit/sftp_test.py

@@ -23,8 +23,8 @@ def sftp_session(ssh_client_session):
 
 
 @pytest.fixture(
-    params=(32, SFTP_MAX_CHUNK + 1),
-    ids=('small-payload', 'large-payload'),
+    params=(32, SFTP_MAX_CHUNK + 1, 255 * 1024 + 1),
+    ids=('small-payload', 'large-payload', 'huge-payload'),
 )
 def transmit_payload(request: pytest.FixtureRequest) -> bytes:
     """Generate binary test payloads of assorted sizes.
@@ -34,6 +34,9 @@ def transmit_payload(request: pytest.FixtureRequest) -> bytes:
     The choice SFTP_MAX_CHUNK + 1 (32kB + 1B) is meant to be 1B larger than the chunk
     size used in :file:`sftp.pyx` to make sure we excercise at least two rounds of
     reading/writing.
+
+    The Choice T 255kB + 1B is meant to be 1B larger than OpenSSH SFTP server supported
+    maximum reads and writes of 256 * 1024 - 1024 B per request.
     """
     payload_len = request.param
     random_bytes = [ord(random.choice(string.printable)) for _ in range(payload_len)]