Test biotest failing on FreeBSD about openbsd HOT 4 CLOSED

True. IIRC the results vary over other OSes as well, which is why LibreSSL portable does not enable this test by default. I've thought about including the OpenBSD inet_pton in the compat layer for the sake of consistency.

from openbsd.

biotest results of other platforms, here.
I built biotest by ./configure --enable-extratests.

• HP-UX 11i (both gcc and C/aC++)
  FAIL: test 2 ("1") success, want failure
  FAIL: test 3 ("1.2") success, want failure
  FAIL: test 4 ("1.2.3") success, want failure
  FAIL: test 11 ("imaps") failure, want success
  FAIL biotest (exit status: 1)
• CentOS7
  FAIL: test 2 ("1") success, want failure
  FAIL: test 3 ("1.2") success, want failure
  FAIL: test 4 ("1.2.3") success, want failure
  FAIL: test 1 ("") success, want failure
  FAIL biotest (exit status: 1)
• Solaris 11.2 i386
  FAIL: test 2 ("1") success, want failure
  FAIL: test 3 ("1.2") success, want failure
  FAIL: test 4 ("1.2.3") success, want failure
  FAIL: test 13 ("0xff.0xff.0xff.0xff") success, want failure
  FAIL: test 1 ("") success, want failure
  FAIL: test 11 ("imaps") failure, want success
• Cygwin64
  FAIL: test 0 ("") success, want failure
  FAIL: test 1 ("") success, want failure
  FAIL biotest.exe (exit status: 1)
• MinGW64
  FAIL: test 11 ("localhost") failure, want success
  FAIL: test 11 ("imaps") failure, want success

from openbsd.

The difference between OpenBSD's and FreeBSD's inet_pton4 is very small and both descend from isc/Paul Vixie's code.
POSIX states that the test should fail when there's fewer or more than 4 octets in the input and FreeBSD code indicates this behaviour as well.

The inet_pton() function does not accept other formats (such as the octal numbers, hexadecimal numbers, and fewer than four numbers...

FreeBSD inet_pton.c

@@ -92,16 +84,14 @@
                if ((pch = strchr(digits, ch)) != NULL) {
                        u_int new = *tp * 10 + (pch - digits);

-                       if (saw_digit && *tp == 0)
-                               return (0);
                        if (new > 255)
                                return (0);
-                       *tp = new;
-                       if (!saw_digit) {
+                       if (! saw_digit) {
                                if (++octets > 4)
                                        return (0);
                                saw_digit = 1;
                        }
+                       *tp = new;
                } else if (ch == '.' && saw_digit) {
                        if (octets == 4)
                                return (0);

from openbsd.

In a nutshell, the test requires a posix compliant inet_pton(). We will simply disable
the test on systems that do not have this.

from openbsd.