fix failing test

Author: rikvdh

src/PHPHtmlParser/Dom/AbstractNode.php

@@ -252,8 +252,11 @@ public function isAncestor(int $id): bool
      */
     public function getAncestor(int $id)
     {
-        if ($this->parent !== null && $this->parent->id() == $id) {
-            return $this->parent;
+        if ($this->parent !== null) {
+            if ($this->parent->id() == $id) {
+                return $this->parent;
+            }
+            return $this->parent->getAncestor($id);
         }
         return null;
     }

tests/Node/ParentTest.php

@@ -301,6 +301,7 @@ public function testGetGreatAncestor()
         $parent->addChild($child);
         $child->addChild($child2);
         $ancestor = $child2->getAncestor($parent->id());
+        $this->assertNotNull($ancestor);
         $this->assertEquals($parent->id(), $ancestor->id());
     }