Fix formatObject method to handle null values

Author: joeygrover

android/sdl_android/src/androidTest/java/com/smartdevicelink/test/rpc/RPCStructTests.java

@@ -0,0 +1,48 @@
+package com.smartdevicelink.test.rpc;
+
+import androidx.test.ext.junit.runners.AndroidJUnit4;
+
+import com.smartdevicelink.proxy.RPCStruct;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import static junit.framework.TestCase.assertNotNull;
+
+@RunWith(AndroidJUnit4.class)
+public class RPCStructTests {
+
+    @Test
+    public void testFormatObject() {
+        final String KEY = "LIST";
+        RPCStruct struct = new RPCStruct();
+        List<RPCStruct> structs = new ArrayList<>();
+        struct.setValue(KEY, structs);
+        assertNotNull(struct.getObject(RPCStruct.class, KEY));
+
+        structs.add(new RPCStruct());
+        struct.setValue(KEY, structs);
+        assertNotNull(struct.getObject(RPCStruct.class, KEY));
+
+        structs.clear();
+        structs.add(null);
+        struct.setValue(KEY, structs);
+        assertNotNull(struct.getObject(RPCStruct.class, KEY));
+
+        structs.clear();
+        structs.add(null);
+        structs.add(new RPCStruct());
+        struct.setValue(KEY, structs);
+        assertNotNull(struct.getObject(RPCStruct.class, KEY));
+
+        structs.clear();
+        structs.add(new RPCStruct());
+        structs.add(null);
+        structs.add(new RPCStruct());
+        struct.setValue(KEY, structs);
+        assertNotNull(struct.getObject(RPCStruct.class, KEY));
+    }
+}

base/src/main/java/com/smartdevicelink/proxy/RPCStruct.java

@@ -275,8 +275,18 @@ protected Object formatObject(Class tClass, Object obj){
 		} else if (obj instanceof List<?>) {
 			List<?> list = (List<?>) obj;
 			if (list != null && list.size() > 0) {
-				Object item = list.get(0);
-				if (tClass.isInstance(item)) {
+				Object item = null;
+				//Iterate through list to find first non-null object
+				for(Object object: list){
+					if(object != null) {
+						item = object;
+						break;
+					}
+				}
+
+				if (item == null) {
+					return list;
+				} else if (tClass.isInstance(item)) {
 					return list;
 				} else if (item instanceof Hashtable) {
 					List<Object> newList = new ArrayList<Object>();
@@ -307,6 +317,10 @@ protected Object formatObject(Class tClass, Object obj){
 					}
 					return newList;
 				}
+			} else {
+				//If the list is either null or empty it should be returned. It will keep the same
+				//behavior as it does today with null lists, but empty ones will now also be returned.
+				return list;
 			}
 		}
 		return null;