bug #21208 [Validator] Add object handling of invalid constraints in Composite (SenseException)

This PR was submitted for the master branch but it was merged into the 2.7 branch instead (closes #21208).

Discussion
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[Validator] Add object handling of invalid constraints in Composite

| Q             | A
| ------------- | ---
| Branch?       | 2.7
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | #21206
| License       | MIT
| Doc PR        | n/a

This PR fixes a minor bug described in #21206. The constraint `Symfony\Component\Validator\Constraints\Composite` doesn't check in it's exception handling if the wrongly created instance of a nested constraint is an object, which is the expected type for a constraint.

Commits
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4bd2c22871 [Validator] Add object handling of invalid constraints in Composite

src/Symfony/Component/Validator/Constraints/Composite.php

@@ -67,6 +67,10 @@ abstract class Composite extends Constraint
 
         foreach ($nestedConstraints as $constraint) {
             if (!$constraint instanceof Constraint) {
+                if (is_object($constraint)) {
+                    $constraint = get_class($constraint);
+                }
+
                 throw new ConstraintDefinitionException(sprintf('The value %s is not an instance of Constraint in constraint %s', $constraint, get_class($this)));
             }
 

src/Symfony/Component/Validator/Tests/Constraints/CompositeTest.php

@@ -125,6 +125,17 @@ class CompositeTest extends TestCase
         ));
     }
 
+    /**
+     * @expectedException \Symfony\Component\Validator\Exception\ConstraintDefinitionException
+     */
+    public function testFailIfNoConstraintObject()
+    {
+        new ConcreteComposite(array(
+            new NotNull(array('groups' => 'Default')),
+            new \ArrayObject(),
+        ));
+    }
+
     /**
      * @expectedException \Symfony\Component\Validator\Exception\ConstraintDefinitionException
      */