Added support for deserializing from null input to a null value.

Added toString() method to ObjectTypePair.

gson/src/main/java/com/google/gson/Gson.java

@@ -415,6 +415,9 @@ public final class Gson {
    */
   @SuppressWarnings("unchecked")
   public <T> T fromJson(String json, Type typeOfT) throws JsonParseException {
+    if (json == null) {
+      return null;
+    }
     StringReader reader = new StringReader(json);
     T target = (T) fromJson(reader, typeOfT);
     return target;

gson/src/main/java/com/google/gson/ObjectTypePair.java

@@ -44,7 +44,12 @@ final class ObjectTypePair {
   Type getType() {
     return type;
   }
-  
+
+  @Override
+  public String toString() {
+    return String.format("preserveType: %b, type: %s, obj: %s", preserveType, type, obj);
+  }
+
   <HANDLER> Pair<HANDLER, ObjectTypePair> getMatchingHandler(
       ParameterizedTypeHandlerMap<HANDLER> handlers) {
     HANDLER handler = null;

gson/src/test/java/com/google/gson/functional/ObjectTest.java

@@ -140,11 +140,17 @@ public class ObjectTest extends TestCase {
     assertEquals("", gson.toJson(null));
   }
 
-  public void testNullDeserialization() throws Exception {
+  public void testEmptyStringDeserialization() throws Exception {
     Object object = gson.fromJson("", Object.class);
     assertNull(object);
   }
 
+  public void testNullDeserialization() throws Exception {
+    String myNullObject = null;
+    Object object = gson.fromJson(myNullObject, Object.class);
+    assertNull(object);
+  }
+
   public void testNullFieldsSerialization() throws Exception {
     Nested target = new Nested(new BagOfPrimitives(10, 20, false, "stringValue"), null);
     assertEquals(target.getExpectedJson(), gson.toJson(target));