Handle missing GPS provider

app/src/main/java/org/traccar/client/MainActivity.java

@@ -239,7 +239,10 @@ public class MainActivity extends PreferenceActivity implements OnSharedPreferen
             if (missingPermissions.isEmpty()) {
                 permission = true;
             } else {
-                requestPermissions(missingPermissions.toArray(new String[missingPermissions.size()]), PERMISSIONS_REQUEST_LOCATION);
+                if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
+                    requestPermissions(missingPermissions.toArray(new String[missingPermissions.size()]),
+                            PERMISSIONS_REQUEST_LOCATION);
+                }
                 return;
             }
         }

app/src/main/java/org/traccar/client/MixedPositionProvider.java

@@ -23,6 +23,7 @@ import android.location.LocationManager;
 import android.os.Bundle;
 import android.util.Log;
 
+@SuppressWarnings("MissingPermission")
 public class MixedPositionProvider extends PositionProvider implements LocationListener, GpsStatus.Listener {
 
     private static int FIX_TIMEOUT = 30 * 1000;
@@ -37,7 +38,11 @@ public class MixedPositionProvider extends PositionProvider implements LocationL
     public void startUpdates() {
         lastFixTime = System.currentTimeMillis();
         locationManager.addGpsStatusListener(this);
+        try {
             locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, period, 0, this);
+        } catch (IllegalArgumentException e) {
+            Log.w(TAG, e);
+        }
     }
 
     public void stopUpdates() {

app/src/main/java/org/traccar/client/SimplePositionProvider.java

@@ -20,7 +20,9 @@ import android.location.Location;
 import android.location.LocationListener;
 import android.location.LocationManager;
 import android.os.Bundle;
+import android.util.Log;
 
+@SuppressWarnings("MissingPermission")
 public class SimplePositionProvider extends PositionProvider implements LocationListener {
 
     public SimplePositionProvider(Context context, PositionListener listener) {
@@ -31,7 +33,11 @@ public class SimplePositionProvider extends PositionProvider implements Location
     }
 
     public void startUpdates() {
+        try {
             locationManager.requestLocationUpdates(type, period, 0, this);
+        } catch (IllegalArgumentException e) {
+            Log.w(TAG, e);
+        }
     }
 
     public void stopUpdates() {