linux: the default hostname is (none)

It's blank for the BSD's.
Respect this when relinquishing the hostname.

Author: rsmarples

.gitignore

@@ -19,6 +19,7 @@ dhcpcd.8
 dhcpcd-run-hooks
 dhcpcd-run-hooks.8
 dhcpcd.conf.5
+hooks/30-hostname
 hooks/50-ypbind
 
 # Ignore distribution

Makefile.inc

@@ -32,3 +32,4 @@ SED_SERVICESTATUS=	-e 's:@SERVICESTATUS@:${SERVICESTATUS}:g'
 SED_STATUSARG=		-e 's:@STATUSARG@:${STATUSARG}:g'
 SED_SCRIPT=		-e 's:@SCRIPT@:${SCRIPT}:g'
 SED_SYS=		-e 's:@SYSCONFDIR@:${SYSCONFDIR}:g'
+SED_DEFAULT_HOSTNAME=	-e 's:@DEFAULT_HOSTNAME@:${DEFAULT_HOSTNAME}:g'

configure

@@ -87,6 +87,7 @@ for x do
 	PKG_CONFIG) PKG_CONFIG=$var;;
 	--with-hook) HOOKSCRIPTS="$HOOKSCRIPTS${HOOKSCRIPTS:+ }$var";;
 	--with-hooks|HOOKSCRIPTS) HOOKSCRIPTS=$var; HOOKSET=true;;
+	--with-default-hostname) _DEFAULT_HOSTNAME=$var;;
 	--build) BUILD=$var;;
 	--host) HOST=$var; HOSTCC=$var-;;
 	--target) TARGET=$var;;
@@ -494,6 +495,16 @@ solaris*|sunos*)
 	;;
 esac
 
+if [ -n "${_DEFAULT_HOSTNAME+x}" ]; then
+	DEFAULT_HOSTNAME="${_DEFAULT_HOSTNAME}"
+else
+	case "$OS" in
+	*|linux*)	DEFAULT_HOSTNAME="(none)";;
+	*)	DEFAULT_HOSTNAME="";;
+	esac
+fi
+echo "DEFAULT_HOSTNAME=		$DEFAULT_HOSTNAME" >>$CONFIG_MK
+
 if [ -z "$INET" -o "$INET" = yes ]; then
 	echo "Enabling INET support"
 	echo "CPPFLAGS+=	-DINET" >>$CONFIG_MK

hooks/30-hostname renamed to hooks/30-hostname.in

@@ -17,7 +17,7 @@
 
 # If we used to set the hostname, but relinquish control of it, we should
 # reset to the default value.
-: ${hostname_default=}
+: ${hostname_default=@DEFAULT_HOSTNAME@}
 
 # Some systems don't have hostname(1)
 _hostname()
@@ -54,7 +54,7 @@ _hostname()
 is_default_hostname()
 {
 	case "$1" in
-	""|"(none)"|localhost|localhost.localdomain|"$hostname_default")
+	""|"$hostname_default"|localhost|localhost.localdomain)
 		return 0;;
 	esac
 	return 1

hooks/Makefile

@@ -27,6 +27,7 @@ FILES+=		${EGHOOKSCRIPTS}
 		${SED_SYS} ${SED_SCRIPT} ${SED_DATADIR} \
 		${SED_SERVICEEXISTS} ${SED_SERVICECMD} ${SED_SERVICESTATUS} \
 		${SED_STATUSARG} \
+		${SED_DEFAULT_HOSTNAME} \
 		-e 's:@YPDOMAIN_DIR@:${YPDOMAIN_DIR}:g' \
 		-e 's:@YPDOMAIN_SUFFIX@:${YPDOMAIN_SUFFIX}:g' \
 		$< > $@