build/autotools: fail configure if netconfig/resolveconf tool is not found

If the user explicitly passes --with-netconfig=$PATH or --with-resolvconf=$PATH,
the path is accepted as is. We only do autodetection, if the binary was not found.

In that case, if the binary cannot be found in the common paths fail compilation.

(cherry picked from commit 5b36585a3d)

.travis.yml

@@ -108,8 +108,8 @@ script:
               -D dhcpcanon=/bin/nowhere/dhcpcanon \
               -D dhcpcd=/bin/nowhere/dhcpd \
               \
-              -D netconfig=true \
-              -D resolvconf=true \
+              -D netconfig=/bin/nowhere/netconfig \
+              -D resolvconf=/bin/nowhere/resolvconf \
               \
               -D ifcfg_rh=false \
               -D ibft=true \
@@ -146,8 +146,8 @@ script:
               --with-dhcpcd=yes \
               --with-dhclient=yes \
               \
-              --with-netconfig=no \
-              --with-resolvconf=yes \
+              --with-netconfig=/bin/nowhere/netconfig \
+              --with-resolvconf=/bin/nowhere/resolvconf \
               \
               --enable-ifcfg-rh=yes \
               --enable-config-plugin-ibft=yes \

configure.ac

@@ -871,13 +871,12 @@ test -z "$config_dhcp_default"                             && config_dhcp_defaul
 AC_DEFINE_UNQUOTED(NM_CONFIG_DEFAULT_MAIN_DHCP, "$config_dhcp_default", [Default configuration option for main.dhcp setting])
 AC_SUBST(NM_CONFIG_DEFAULT_MAIN_DHCP, $config_dhcp_default)
 
-# resolvconf and netconfig support
 AC_ARG_WITH(resolvconf, AS_HELP_STRING([--with-resolvconf=yes|no|path], [Enable resolvconf support]))
 AC_ARG_WITH(netconfig, AS_HELP_STRING([--with-netconfig=yes|no], [Enable SUSE netconfig support]))
 AC_ARG_WITH(config-dns-rc-manager-default, AS_HELP_STRING([--with-config-dns-rc-manager-default=symlink|file|netconfig|resolvconf], [Configure default value for main.rc-manager setting]), [config_dns_rc_manager_default=$withval])
-if test "$config_dns_rc_manager_default" != symlink -a \
+if test "$config_dns_rc_manager_default" != "" -a \
         "$config_dns_rc_manager_default" != file -a \
-        "$config_dns_rc_manager_default" != "" -a \
+        "$config_dns_rc_manager_default" != symlink -a \
         "$config_dns_rc_manager_default" != netconfig -a \
         "$config_dns_rc_manager_default" != resolvconf; then
 	AC_MSG_WARN([Unknown --with-config-dns-rc-manager-default=$config_dns_rc_manager_default setting.])
@@ -888,21 +887,29 @@ AS_IF([test -z "$with_netconfig" -a -f /etc/SuSE-release], with_netconfig=yes)
 # Otherwise default to "no"
 AS_IF([test -z "$with_resolvconf"], with_resolvconf=no)
 AS_IF([test -z "$with_netconfig"], with_netconfig=no)
-# Find resolvconf and netconfig
+
 if test "$with_resolvconf" = "yes"; then
-	AC_PATH_PROGS(with_resolvconf, resolvconf, no, /sbin:/usr/sbin:/usr/local/sbin)
+	AC_PATH_PROGS(with_resolvconf, resolvconf, 'yes', /sbin:/usr/sbin:/usr/local/sbin)
+	if test "$with_resolvconf" = "yes"; then
+		AC_MSG_ERROR(cannot find resolvconf in path. Set the path explicitly via --with-resolvconf=PATH.)
+	fi
 fi
 if test "$with_resolvconf" != "no"; then
 	AS_IF([test -z "$config_dns_rc_manager_default"], config_dns_rc_manager_default=resolvconf)
 fi
+
 if test "$with_netconfig" = "yes"; then
-	AC_PATH_PROGS(with_netconfig, netconfig, no, /sbin:/usr/sbin:/usr/local/sbin)
+	AC_PATH_PROGS(with_netconfig, netconfig, yes, /sbin:/usr/sbin:/usr/local/sbin)
+	if test "$with_netconfig" = "yes"; then
+		AC_MSG_ERROR(cannot find netconfig in path. Set the path explicitly via --with-netconfig=PATH.)
+	fi
 fi
 if test "$with_netconfig" != "no"; then
 	AS_IF([test -z "$config_dns_rc_manager_default"], config_dns_rc_manager_default=netconfig)
 fi
+
 AS_IF([test -z "$config_dns_rc_manager_default"], config_dns_rc_manager_default=symlink)
-# Define resolvconf and netconfig paths
+
 if test "$with_resolvconf" != "no"; then
 	AC_DEFINE_UNQUOTED(RESOLVCONF_PATH, "$with_resolvconf", [Path to resolvconf])
 fi