Hi,
I've noticed an issue when testing the "rep" capability to st (terminal
emulator) on OpenBSD.
After some digging I found the issue is when BSD_TPUTS is defined
(ncurses_cfg.h). This enables code for BSD prefix padding and a workaround for
nethack and ancient BSD terminals as the C comment says in the file
tinfo/lib_tputs.c.
I noticed while using the lynx browser, it will incorrectly print repeated
digit characters. For example:
echo "Z0000000" | lynx -stdin
will print: "ZZZZZZZZ"
To reproduce it:
* Use a terminal with the "rep" capability supported and exposed:
rep=%p1%c\E[%p2%{1}%-%db
infocmp | grep rep=
The sequence is documented in terminfo(5).
* Compile ncurses with BSD_TPUTS defined (or ./configure --enable-bsdpad on
Linux).
BSD_TPUTS is set by default on OpenBSD in lib/libcurses/ncurses_cfg.h
I could reproduce the issue on Void Linux also on the latest ncurses snapshot,
but a fix has been sent upstream and added in 20200523:
https://github.com/ThomasDickey/ncurses-snapshots/blob/master/NEWS
"+ add a check in EmitRange to guard against repeat_char emitting digits which
could be interpreted as BSD-style padding when --enable-bsdpad is configured
(report/patch by Hiltjo Posthuma)."
A small program to reproduce it:
#include <curses.h>
#include <term.h>
#include <unistd.h>
int
main(void)
{
WINDOW *win;
win = initscr();
printw("Z0000000");
refresh();
sleep(5);
return 0;
}
This program will incorrectly print "ZZZZZZZZ" also.
The backported below patch from ncurses snapshot 20200523 to -current fixes it:
diff --git a/lib/libcurses/tty/tty_update.c b/lib/libcurses/tty/tty_update.c
index bd2f088adf6..3d10b76cce2 100644
--- a/lib/libcurses/tty/tty_update.c
+++ b/lib/libcurses/tty/tty_update.c
@@ -540,7 +540,11 @@ EmitRange(const NCURSES_CH_T * ntext, int num)
} else {
return 1; /* cursor stays in the middle */
}
- } else if (repeat_char && runcount > SP->_rep_cost) {
+ } else if (repeat_char &&
+#if BSD_TPUTS
+ !isdigit(UChar(CharOf(ntext0))) &&
+#endif
+ runcount > SP->_rep_cost) {
bool wrap_possible = (SP->_curscol + runcount >=
screen_columns);
int rep_count = runcount;
Is there a specific reason why OpenBSD still uses an old ncurses-based version?
--
Kind regards,
Hiltjo
