Use wpa_cli to check WiFi country setting

debian/changelog

@@ -1,3 +1,9 @@
+raspi-config (20190502) buster; urgency=medium
+
+  * Use wpa_cli to check WiFi country setting
+
+ -- Serge Schneider <serge@raspberrypi.org>  Thu, 02 May 2019 13:22:49 +0100
+
 raspi-config (20190429) buster; urgency=medium
 
   * Update do_wifi_country

raspi-config

@@ -429,7 +429,25 @@ do_change_timezone() {
 }
 
 get_wifi_country() {
-   grep country= /etc/wpa_supplicant/wpa_supplicant.conf | cut -d "=" -f 2
+  IFACE="$(list_wlan_interfaces | head -n 1)"
+  if [ -z "$IFACE" ]; then
+    if [ "$INTERACTIVE" = True ]; then
+      whiptail --msgbox "No wireless interface found" 20 60
+    fi
+    return 1
+  fi
+  if ! wpa_cli -i "$IFACE" status > /dev/null 2>&1; then
+    if [ "$INTERACTIVE" = True ]; then
+      whiptail --msgbox "Could not communicate with wpa_supplicant" 20 60
+    fi
+    return 1
+  fi
+  wpa_cli -i "$IFACE" reconfigure > /dev/null 2>&1
+  COUNTRY="$(wpa_cli -i "$IFACE" get country)"
+  if [ "$COUNTRY" = "FAIL" ]; then
+    return 1
+  fi
+  echo "$COUNTRY"
 }
 
 do_wifi_country() {