base-files: Fix config_generate when there are no switch VLANs or ports configured in board.json.

The json_select call fails when there are no roles or ports objects in board.json. "json_select .." must not be executed after failing.

This fixes for example LEDs not being set up in /etc/config/system.

Signed-off-by: Vittorio Gambaletta <openwrt@vittgam.net>

package/base-files/files/bin/config_generate

@@ -143,55 +143,59 @@ generate_switch_vlans_ports() {
 	# autogenerate vlans
 	#
 
-	json_get_keys roles roles
+	if json_is_a roles array; then
-	json_select roles
+		json_get_keys roles roles
+		json_select roles
 
-	for role in $roles; do
+		for role in $roles; do
-		json_select "$role"
+			json_select "$role"
-			json_get_vars ports
+				json_get_vars ports
-		json_select ..
+			json_select ..
 
-		uci -q batch <<-EOF
+			uci -q batch <<-EOF
-			add network switch_vlan
+				add network switch_vlan
-			set network.@switch_vlan[-1].device='$switch'
+				set network.@switch_vlan[-1].device='$switch'
-			set network.@switch_vlan[-1].vlan='$role'
+				set network.@switch_vlan[-1].vlan='$role'
-			set network.@switch_vlan[-1].ports='$ports'
+				set network.@switch_vlan[-1].ports='$ports'
-		EOF
+			EOF
-	done
+		done
 
-	json_select ..
+		json_select ..
+	fi
 
 
 	#
 	# write port specific settings
 	#
 
-	json_get_keys ports ports
+	if json_is_a ports array; then
-	json_select ports
+		json_get_keys ports ports
+		json_select ports
+
+		for port in $ports; do
+			json_select "$port"
+				json_get_vars num
+
+				if json_is_a attr object; then
+					json_get_keys attr attr
+					json_select attr
+						uci -q batch <<-EOF
+							add network switch_port
+							set network.@switch_port[-1].device='$switch'
+							set network.@switch_port[-1].port=$num
+						EOF
+
+						for attr in $attr; do
+							json_get_var val "$attr"
+							uci -q set network.@switch_port[-1].$attr="$val"
+						done
+					json_select ..
+				fi
+			json_select ..
+		done
 
-	for port in $ports; do
-		json_select "$port"
-			json_get_vars num
-
-			if json_is_a attr object; then
-				json_get_keys attr attr
-				json_select attr
-					uci -q batch <<-EOF
-						add network switch_port
-						set network.@switch_port[-1].device='$switch'
-						set network.@switch_port[-1].port=$num
-					EOF
-
-					for attr in $attr; do
-						json_get_var val "$attr"
-						uci -q set network.@switch_port[-1].$attr="$val"
-					done
-				json_select ..
-			fi
 		json_select ..
-	done
+	fi
-
-	json_select ..
 }
 
 generate_switch() {