When connecting from an rxvt terminal on my FreeBSD daily-driver to my OpenBSD 7.4 server, tmux sends the CSI requesting color information. But when rxvt replies, tmux ignores the reply and the resulting answer dumps answer-back garbage into my session as if I typed it. At a prompt, it's largely just an annoyance since I can control+u to clear it; but if if the session is pointed at some TUI program, the answer-back garbage can really mess with the session.
If I'm within rxvt on FreeBSD (also v9.31), and I create a new session or attempt to attach to an existing one (regardless of what $TERM was set when the tmux session was started), I get the answer-back garbage. If I use xterm or suckless `st`, or the rxvt from OpenBSD's packages used locally it doesn't happen. The full conversation thread is here[1] and according to /u/sdk-dev who was able to reproduce and narrow down the changes, they say that it broke in this change[2] where these two lines[3] were moved outside of some checks. As best we can tell, tmux is failing to consume the answer-back it requests. Thanks, -tkc [1] https://www.reddit.com/r/openbsd/comments/18cxwdy/tmux_causing_ansi_colorresponse_garbage_on/ [2] /* $OpenBSD: tty.c,v 1.434 2023/09/02 20:03:10 nicm Exp $ */ https://github.com/openbsd/src/commit/903d1285474e6a1a8bfdc71e5c97f8037e5d801a#diff-f63cc050113818ea4ebd794e00daec9960f613b4dbd2039bed3d532c7ea8096dR373 [3] https://github.com/openbsd/src/blob/master/usr.bin/tmux/tty.c#L373-L374