override property constraints in child class

src/Symfony/Component/Validator/Mapping/ClassMetadata.php

@@ -346,6 +346,10 @@ class ClassMetadata extends ElementMetadata implements ClassMetadataInterface
         }
 
         foreach ($source->getConstrainedProperties() as $property) {
+            if ($this->hasPropertyMetadata($property)) {
+                continue;
+            }
+
             foreach ($source->getPropertyMetadata($property) as $member) {
                 $member = clone $member;
 

src/Symfony/Component/Validator/Tests/Mapping/ClassMetadataTest.php

@@ -12,6 +12,7 @@
 namespace Symfony\Component\Validator\Tests\Mapping;
 
 use Symfony\Component\Validator\Constraint;
+use Symfony\Component\Validator\Constraints\GreaterThan;
 use Symfony\Component\Validator\Constraints\Valid;
 use Symfony\Component\Validator\Mapping\ClassMetadata;
 use Symfony\Component\Validator\Tests\Fixtures\ConstraintA;
@@ -295,4 +296,29 @@ class ClassMetadataTest extends \PHPUnit_Framework_TestCase
     {
         $this->assertCount(0, $this->metadata->getPropertyMetadata('foo'), '->getPropertyMetadata() returns an empty collection if no metadata is configured for the given property');
     }
+
+    public function testMergeDoesOverrideConstraintsFromParentClassIfPropertyIsOverriddenInChildClass()
+    {
+        $parentMetadata = new ClassMetadata('\Symfony\Component\Validator\Tests\Mapping\ParentClass');
+        $parentMetadata->addPropertyConstraint('example', new GreaterThan(0));
+
+        $childMetadata = new ClassMetadata('\Symfony\Component\Validator\Tests\Mapping\ChildClass');
+        $childMetadata->addPropertyConstraint('example', new GreaterThan(1));
+        $childMetadata->mergeConstraints($parentMetadata);
+
+        $expectedMetadata = new ClassMetadata('\Symfony\Component\Validator\Tests\Mapping\ChildClass');
+        $expectedMetadata->addPropertyConstraint('example', new GreaterThan(1));
+
+        $this->assertEquals($expectedMetadata, $childMetadata);
+    }
+}
+
+class ParentClass
+{
+    public $example = 0;
+}
+
+class ChildClass extends ParentClass
+{
+    public $example = 1;    // overrides parent property of same name
 }