Pin the no-pipelining invariant on the PTY upgrade

Shipped

September 3, 2026 at 5:57 PM UTC

Author

Kamo

Commit

0cbb2c5

self.rfile is a BUFFERED reader over the socket and pump reads the RAW socket, so a caller that sent bytes behind its request line would strand them in that buffer and the terminal would lose its first keystrokes with nothing to show for it. DevMachinePtyClient reads the 101 before writing anything, which is what makes this safe today; nothing here can detect a caller that stops doing so, so it is stated on both sides.