Hello, I discovered an issue with ncurses on Slackware, both version 6.3 used in Slackware 15.0 and 6.6 used in Slackware-current. I was testing a real serial terminal - a Tandy DT-1 set to emulate a tvi910.
It turns out that, for all ncurses apps, with TERM=tvi910 I get a bunch of spaces being printed all the time, instead of optimized cursor movement. I tried the same configuration on Debian 13 (trixie) as well as arch, and these work fine. So I started to suspect the issue is something specific to the configure options used by Slackware. I tested some other terminal types, vt100 and adm3a, and they seem to be unaffected. I have written a trivial test program here: https://github.com/palazzol/ncurses_test And, I think I have narrowed it down to the configure option --enable-wmc-glitch option, which Slackware uses. It seems like this causes the bad behavior with this terminal type. If I rebuild ncurses without that, everything works fine. Is this kind of dramatic failure expected when using that option? I see it is marked as "experimental". I'm honestly not sure if my trace has captured the root cause yet, but you can see that the test program generates <100 bytes when working properly, or >2K bytes when not. Thanks!
