Evitando NullPointerException quando CPF é nulo
diff --git a/stella-faces/src/main/java/br/com/caelum/stella/faces/validation/StellaCPFValidator.java b/stella-faces/src/main/java/br/com/caelum/stella/faces/validation/StellaCPFValidator.java
index 68e4aa8..44518d6 100644
--- a/stella-faces/src/main/java/br/com/caelum/stella/faces/validation/StellaCPFValidator.java
+++ b/stella-faces/src/main/java/br/com/caelum/stella/faces/validation/StellaCPFValidator.java
@@ -57,6 +57,8 @@
     }
 
     public void validate(FacesContext facesContext, UIComponent uiComponent, Object value) throws ValidatorException {
+    	if (value == null) return;
+    	
         ResourceBundle bundle = resourceBundleFinder.getForCurrentLocale(facesContext);
         ResourceBundleMessageProducer producer = new ResourceBundleMessageProducer(bundle);
         CPFValidator validator = new CPFValidator(producer, formatted);
diff --git a/stella-faces/src/test/java/br/com/caelum/stella/faces/validation/StellaCPFValidatorTest.java b/stella-faces/src/test/java/br/com/caelum/stella/faces/validation/StellaCPFValidatorTest.java
index 98e61e9..6e315dd 100644
--- a/stella-faces/src/test/java/br/com/caelum/stella/faces/validation/StellaCPFValidatorTest.java
+++ b/stella-faces/src/test/java/br/com/caelum/stella/faces/validation/StellaCPFValidatorTest.java
@@ -89,4 +89,20 @@
             fail("shouldn't throw exception for valid cpf with leading zeros");
         }
     }
+
+    @Test
+    public void shouldNotThrowNullPointerExceptionWhenCPFIsNull() {
+        final FacesContext context = mockery.mock(FacesContext.class);
+        final UIComponent component = mockery.mock(UIComponent.class);
+        facesContextMocker.mockMessageBundle(context, "messages", Locale.getDefault());
+
+        try {
+            validator.validate(context, component, null);
+            mockery.assertIsSatisfied();
+        } catch (ValidatorException e) {
+            fail("shouldn't throw exception for null cpf");
+        } catch (NullPointerException e) {
+        	fail("shouldn't throw exception for null cpf");
+        }
+    }
 }