Add more nullsafe operators

Author: nicolas-grekas

Button.php

@@ -271,7 +271,7 @@ public function isRequired(): bool
      */
     public function isDisabled(): bool
     {
-        if ($this->parent && $this->parent->isDisabled()) {
+        if ($this->parent?->isDisabled()) {
             return true;
         }
 

Extension/DataCollector/FormDataCollector.php

@@ -326,9 +326,7 @@ private function &recursiveBuildFinalFormTree(FormInterface $form = null, FormVi
         foreach ($view->children as $name => $childView) {
             // The CSRF token, for example, is never added to the form tree.
             // It is only present in the view.
-            $childForm = null !== $form && $form->has($name)
-                ? $form->get($name)
-                : null;
+            $childForm = $form?->has($name) ? $form->get($name) : null;
 
             $output['children'][$name] = &$this->recursiveBuildFinalFormTree($childForm, $childView, $outputByHash);
         }

Form.php

@@ -196,7 +196,7 @@ public function getPropertyPath(): ?PropertyPathInterface
 
         $parent = $this->parent;
 
-        while ($parent && $parent->getConfig()->getInheritData()) {
+        while ($parent?->getConfig()->getInheritData()) {
             $parent = $parent->getParent();
         }