On Thu, 28 Aug 2025 05:36:06 +0200 Thomas Wolff wrote: > When running wsl.exe from mintty, typing ^O corrupts terminal display. > This was reported in > https://github.com/mintty/mintty/issues/1332 > and I later reported it towards Windows conpty > https://github.com/microsoft/terminal/issues/19285 > but conpty is unlikely the cause, as testing suggests. > > Test case, in mintty: > wsl > ls -1 /bin > ^O # enter the control character > ls -1 /bin # repeat > > The same happens in xterm and some other terminals, but not all. > > Mintty uses a loop to read terminal output from the pty and fill its buffer: > do { > int ret = read(pty_fd, buf + len, sizeof buf - len); > if (ret > 0) > len += ret; > else > break; > } while (len < sizeof buf); > Tracing the loop shows that, while running wsl, after having entered ^O, > every subsequent read returns -1. > Taking out the loop (by patching it, or currently by using option Baud > with some high value) fixes the problem. > I suspect some very obscure interworking problem between wsl/conpty and > cygwin pty handling. As noted in the latter issue, it does not happen > with terminals running remotely, so the suspicion goes more to the > cygwin side. > What’s the role of ^O in this puzzle? Does it trigger something in cygwin? > Is there anything peculiar that would cause pty chunks not be recognised > and then skipped in such a loop?
Thanks for the report. I fixed the Ctrl^O (FLUSHO) handling. Please try cygwin-3.7.0-dev-286-g7b5fb35e. -- Takashi Yano <[email protected]> -- Problem reports: https://cygwin.com/problems.html FAQ: https://cygwin.com/faq/ Documentation: https://cygwin.com/docs.html Unsubscribe info: https://cygwin.com/ml/#unsubscribe-simple
