Optional validator should pass null through to inner validator.

Change-Id: I9b8ad2dca5d93dae3c656c5334ff916604d8c826
Reviewed-on: http://gerrit.dmdirc.com/2635
Reviewed-by: Chris Smith <chris@dmdirc.com>
Automatic-Compile: DMDirc Build Manager

src/com/dmdirc/util/validators/OptionalValidator.java

  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  * SOFTWARE.
  */
-
 package com.dmdirc.util.validators;
 
 /**
  */
 public class OptionalValidator implements Validator<String> {
 
-    /** The minimum value for this number. */
+    /**
+     * The validator to validate the optional setting.
+     */
     protected final Validator<String> validator;
 
     /**
         return validator;
     }
 
-    /** {@inheritDoc} */
+    /**
+     * {@inheritDoc}
+     */
     @Override
     public ValidationResponse validate(final String object) {
+        if (object == null) {
+            return validator.validate(object);
+        }
+
         final int colonIndex = object.indexOf(':');
 
         if (colonIndex == -1) {
 
         return validator.validate(object);
     }
-
 }

test/com/dmdirc/util/validators/OptionalValidatorTest.java

  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  * SOFTWARE.
  */
-
 package com.dmdirc.util.validators;
 
 import org.junit.Test;
         assertEquals(validator, instance.getValidator());
     }
 
+    @Test
+    public void testNullValue() {
+        final Validator<String> validator = new NotEmptyValidator();
+        final OptionalValidator instance = new OptionalValidator(validator);
+        assertTrue(instance.validate(null).isFailure());
+    }
+
     @Test
     public void testNoSeparator() {
         final ValidationResponse res = new OptionalValidator(new StringLengthValidator(0, 3))
         assertTrue(res.isFailure());
         assertTrue(res.getFailureReason().contains("at most 2"));
     }
-
-}
+}