Avoid ctype(3) abuses - slock - simple X display locker utility
  HTML git clone git://git.suckless.org/slock
   DIR Log
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   DIR README
   DIR LICENSE
       ---
   DIR commit 55d985a354048e14f408dd731faaf1acbdc277f4
   DIR parent 3791a996e230aec59d61faea46634ae4f031e359
  HTML Author: Leonardo Taccari <leot@NetBSD.org>
       Date:   Mon, 27 Jul 2026 23:27:43 +0200
       
       Avoid ctype(3) abuses
       
       Valid argument of ctype(3) functions must be either EOF or non-negative
       value within the range representable as unsigned char. Invalid values
       leads to undefined behavior.
       
       Cast all such uses to avoid that.
       
       At least in NetBSD 11 ctype(3) abuses will always crash and permit
       to break slock screen locking.
       
       Diffstat:
         M slock.c                             |       2 +-
       
       1 file changed, 1 insertion(+), 1 deletion(-)
       ---
   DIR diff --git a/slock.c b/slock.c
       @@ -181,7 +181,7 @@ readpw(Display *dpy, struct xrandr *rr, struct lock **locks, int nscreens,
                                                passwd[--len] = '\0';
                                        break;
                                default:
       -                                if (num && !iscntrl((int)buf[0]) &&
       +                                if (num && !iscntrl((unsigned char)buf[0]) &&
                                            (len + num < sizeof(passwd))) {
                                                memcpy(passwd + len, buf, num);
                                                len += num;