Added a check for empty attribute. LDAP-215

core/src/main/java/org/springframework/ldap/core/DirContextAdapter.java

@@ -558,7 +558,7 @@ public class DirContextAdapter implements DirContextOperations {
 	 */
 	public Object getObjectAttribute(String name) {
 		Attribute oneAttr = originalAttrs.get(name);
-		if (oneAttr == null) {
+		if (oneAttr == null || oneAttr.size() == 0) { // LDAP-215
 			return null;
 		}
 		try {

core/src/test/java/org/springframework/ldap/core/DirContextAdapterTest.java

@@ -83,6 +83,19 @@ public class DirContextAdapterTest extends TestCase {
 		assertNull(s);
 	}
 
+	public void testGetStringAttributeDoesExistButWithNoValue() throws Exception {
+		final Attributes attrs = new BasicAttributes();
+		attrs.put(new BasicAttribute("abc"));
+		class TestableDirContextAdapter extends DirContextAdapter {
+			public TestableDirContextAdapter() {
+				super(attrs, null);
+			}
+		}
+		tested = new TestableDirContextAdapter();
+		String s = tested.getStringAttribute("abc");
+		assertNull(s);
+	}
+
 	public void testGetStringAttributeExists() throws Exception {
 		final Attributes attrs = new BasicAttributes();
 		attrs.put(new BasicAttribute("abc", "def"));