It does not happen very often that somebody replies to an over 20 years
old bug, and this seems to have escaped both my and upstream's
attention. Thomas, could you please have a look?
Cheers,
Sven
On 2022-12-06 15:44 -0800, Ben Wong wrote:
> Package: ncurses-bin
> Version: 6.3+20220423-2
> Followup-For: Bug #60377
> Control: tags -1 patch
> Control: tags -1 patch
>
> Dear Maintainer,
>
> This is still a problem. It causes my VT340 serial terminal to hang,
> but not immediately. It happens the next time a program tries to open
> /dev/ttyUSB0, for example, getty after logging out. I presume this
> hasn't been fixed because the bug only affects hardware terminals that
> lack a carrier detect line (such as any DEC terminal connected via
> DEC423 MMJ).
>
> If anything, clocal ought to be asserted by default, not disabled.
> However, I suggest that `reset` should do neither. The man page for
> reset is clear on what it does and it does not mention clocal. I have
> attached a patch which brings the program back into line with its
> documentation.
>
> Thank you,
>
> --Ben
>
>
>
> -- System Information:
> Debian Release: bookworm/sid
> APT prefers testing
> APT policy: (500, 'testing')
> Architecture: amd64 (x86_64)
>
> Kernel: Linux 6.0.0-4-amd64 (SMP w/8 CPU threads; PREEMPT)
> Kernel taint flags: TAINT_SOFTLOCKUP
> 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
>
> Versions of packages ncurses-bin depends on:
> ii libc6 2.36-6
> ii libtinfo6 6.3+20220423-2
>
> ncurses-bin recommends no packages.
>
> ncurses-bin suggests no packages.
>
> -- no debconf information
>
> --- reset_cmd.c.orig 2021-10-02 11:08:44.000000000 -0700
> +++ reset_cmd.c 2022-11-22 16:00:29.005361817 -0800
> @@ -190,13 +190,14 @@
>
> /*
> * Reset the terminal mode bits to a sensible state. Very useful after
> - * a child program dies in raw mode.
> + * a child program dies in raw mode. Requires termios(3) to work.
> */
> void
> reset_tty_settings(int fd, TTY * tty_settings, int noset)
> {
> GET_TTY(fd, tty_settings);
>
> + /* First reset any special characters to their default values */
> #ifdef TERMIOS
> #if defined(VDISCARD) && defined(CDISCARD)
> reset_char(VDISCARD, CDISCARD);
> @@ -228,94 +229,38 @@
> reset_char(VWERASE, CWERASE);
> #endif
>
> - tty_settings->c_iflag &= ~((unsigned) (IGNBRK
> - | PARMRK
> - | INPCK
> - | ISTRIP
> - | INLCR
> - | IGNCR
> -#ifdef IUCLC
> - | IUCLC
> -#endif
> -#ifdef IXANY
> - | IXANY
> -#endif
> - | IXOFF));
>
> + /* Next, the reset command does the following
> + *
> + * sets cooked and echo modes,
> + * turns off cbreak and raw modes and
> + * turns on newline translation on output.
> + *
> + * It does not mess with other settings, such as IXOFF and CLOCAL,
> + * as the correct values depend upon what type of terminal (and
> + * even what type of serial cable) is being used.
> + *
> + * Users who need a blunter instrument can try `stty sane` which
> + * makes presumptions about a "typical" setup.
> + */
> +
> + /* "Cooked" means: brkint ignpar istrip icrnl ixon opost isig icanon */
> + /* Setting cooked automatically turns off "raw" and "cbreak" */
> tty_settings->c_iflag |= (BRKINT
> - | IGNPAR
> - | ICRNL
> - | IXON
> -#ifdef IMAXBEL
> - | IMAXBEL
> -#endif
> - );
> + | IGNPAR
> + | ISTRIP
> + | ICRNL /* Input maps CR to NL */
> + | IXON);
>
> - tty_settings->c_oflag &= ~((unsigned) (0
> -#ifdef OLCUC
> - | OLCUC
> -#endif
> -#ifdef OCRNL
> - | OCRNL
> -#endif
> -#ifdef ONOCR
> - | ONOCR
> -#endif
> -#ifdef ONLRET
> - | ONLRET
> -#endif
> -#ifdef OFILL
> - | OFILL
> -#endif
> -#ifdef OFDEL
> - | OFDEL
> -#endif
> -#ifdef NLDLY
> - | NLDLY
> -#endif
> -#ifdef CRDLY
> - | CRDLY
> -#endif
> -#ifdef TABDLY
> - | TABDLY
> -#endif
> -#ifdef BSDLY
> - | BSDLY
> -#endif
> -#ifdef VTDLY
> - | VTDLY
> -#endif
> -#ifdef FFDLY
> - | FFDLY
> -#endif
> - ));
> + tty_settings->c_iflag &= ~(INLCR); /* Input does not map NL to CR */
>
> tty_settings->c_oflag |= (OPOST
> #ifdef ONLCR
> - | ONLCR
> + | ONLCR /* Output maps NL to CR-NL */
> #endif
> - );
> + );
>
> - tty_settings->c_cflag &= ~((unsigned) (CSIZE
> - | CSTOPB
> - | PARENB
> - | PARODD
> - | CLOCAL));
> - tty_settings->c_cflag |= (CS8 | CREAD);
> - tty_settings->c_lflag &= ~((unsigned) (ECHONL
> - | NOFLSH
> -#ifdef TOSTOP
> - | TOSTOP
> -#endif
> -#ifdef ECHOPTR
> - | ECHOPRT
> -#endif
> -#ifdef XCASE
> - | XCASE
> -#endif
> - ));
> -
> - tty_settings->c_lflag |= (ISIG
> + tty_settings->c_lflag |= (ISIG /* Generate signal on ^C, ^Z, etc
> */
> | ICANON
> | ECHO
> | ECHOE
> @@ -327,7 +272,7 @@
> | ECHOKE
> #endif
> );
> -#endif
> +#endif /* Matches #ifdef TERMIOS */
>
> if (!noset) {
> SET_TTY(fd, tty_settings);
