Fix #49: add support for -8 command line option to allow 8-bit data

This patch allows the user to disable the 8-bit data check in the log
message validator.  If you have experienced problems with logging any
unicode (utf-8) messages after v1.6, this option is for you.

The correct way to handle this is to add proper parser support for the
Unicode BOM, defined in RFC5424[1], as NetBSD syslogd does[2], search
for IS_BOM().

[1]: https://datatracker.ietf.org/doc/html/rfc5424#appendix-A.8
[2]: http://cvsweb.netbsd.org/bsdweb.cgi/src/usr.sbin/syslogd/syslogd.c?rev=1.138

Signed-off-by: Joachim Wiberg <troglobit@gmail.com>

test/Makefile.am

@@ -1,5 +1,5 @@
 EXTRA_DIST       = lib.sh opts.sh
-EXTRA_DIST      += api.sh local.sh remote.sh fwd.sh mark.sh
+EXTRA_DIST      += api.sh local.sh unicode.sh remote.sh fwd.sh mark.sh
 CLEANFILES       = *~ *.trs *.log
 TEST_EXTENSIONS  = .sh
 TESTS_ENVIRONMENT= unshare -mrun
@@ -12,6 +12,7 @@ api_LDADD        = ../src/libsyslog.la
 
 TESTS            = opts.sh
 TESTS           += local.sh
+TESTS           += unicode.sh
 TESTS           += remote.sh
 TESTS           += api.sh
 TESTS           += fwd.sh

test/unicode.sh

@@ -0,0 +1,20 @@
+#!/bin/sh
+# Currently only same as local.sh but with unicode messages
+# From https://github.com/troglobit/sysklogd/issues/49
+# shellcheck disable=SC1090
+if [ x"${srcdir}" = x ]; then
+    srcdir=.
+fi
+. ${srcdir}/lib.sh
+setup -8
+
+MSG="öäüÖÄÜ߀¢§"
+MSG2="…‘’•"
+
+../src/logger -u "${SOCK}" ${MSG}
+grep ${MSG} "${LOG}" || FAIL "Cannot find: ${MSG}"
+
+../src/logger -u "${ALTSOCK}" ${MSG2}
+grep ${MSG2} "${LOG}" || FAIL "Cannot find: ${MSG2}"
+
+OK