Source: ncurses
Version: 6.5+20250216-2
Severity: normal
Tags: upstream
Forwarded: https://lists.gnu.org/archive/html/bug-ncurses/2026-08/msg00014.html
Dear Maintainer,
After a curses program using keypad(win, TRUE) is suspended with
Ctrl-Z (SIGTSTP) and resumed with `fg` (SIGCONT), the terminal is left
out of application keypad mode. The *first* special key pressed after
resume (e.g. an arrow key) is misreported: getch() returns a bare
KEY_ESCAPE (27), typically followed immediately by the escape
sequence's trailing bytes read back as ordinary characters, instead of
the expected KEY_* code. Every special key pressed *after* that first
one is reported correctly again.
This is directly reproducible with dialog(1) (also built from this
source package):
dialog --menu "Test" 15 40 4 1 One 2 Two 3 Three 4 Four
1. Press Down a couple of times: the highlighted item advances
normally.
2. Press Ctrl-Z, then run `fg` to resume. The menu redraws
correctly.
3. Press Down once: instead of moving to the next item, dialog
receives a bare Escape and exits as if Cancel/Esc had been
pressed.
Full root-cause analysis, a minimal C reproducer, and discussion with
upstream (Thomas Dickey) are on the bug-ncurses mailing list; see the
Forwarded: header above and the rest of the thread (msg00015.html
through msg00018.html in the same archive). Upstream has confirmed the
bug is still present in the current ncurses-snapshots sources and in
the latest 6.6-20260808 release; no fix has been applied yet as of
this writing. Filing this mainly for tracking, so it can be
updated/closed once upstream applies a fix and Debian picks up the
corresponding patch.
-- System Information:
Debian Release: 13.6
APT prefers stable-updates
APT policy: (500, 'stable-updates'), (500, 'stable-security'), (500, 'stable')
Architecture: amd64 (x86_64)
Foreign Architectures: i386
Kernel: Linux 6.12.100+deb13-amd64 (SMP w/16 CPU threads; PREEMPT)
Kernel taint flags: TAINT_OOT_MODULE, TAINT_UNSIGNED_MODULE
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8), LANGUAGE not set
Shell: /bin/sh linked to /usr/bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled
