Fix bug in PlaceholderTargetSource for null values

spring-batch-core/src/test/java/org/springframework/batch/core/scope/util/PlaceholderTargetSourceTests.java

@@ -38,6 +38,10 @@ public class PlaceholderTargetSourceTests extends ContextFactorySupport {
 	@Qualifier("withDate")
 	private PlaceholderTargetSource withDate;
 
+	@Autowired
+	@Qualifier("withNull")
+	private PlaceholderTargetSource withNull;
+
 	@Autowired
 	@Qualifier("compound")
 	private PlaceholderTargetSource compound;
@@ -82,6 +86,10 @@ public class PlaceholderTargetSourceTests extends ContextFactorySupport {
 		return date;
 	}
 
+	public String getGarbage() {
+		return null;
+	}
+
 	@Test
 	public void testAfterPropertiesSet() throws Exception {
 		PlaceholderTargetSource targetSource = new PlaceholderTargetSource();
@@ -143,6 +151,13 @@ public class PlaceholderTargetSourceTests extends ContextFactorySupport {
 		assertEquals("bar-#{date}", target.getName());
 	}
 
+	@Test
+	public void testGetNull() {
+		Node target = (Node) withNull.getTarget();
+		// Remains unconverted because null is explicitly excluded
+		assertEquals("bar-#{garbage}", target.getName());
+	}
+
 	public static interface Node {
 		String getName();