Merge branch '5.3' into 5.4

* 5.3:
  [Process] intersect with getenv() in case-insensitive manner to get default envs
  [Serializer] fix support for lazy/unset properties
  Fix redundant type casts
  [Notifier] Fix AllMySms bridge body content
  Revert "[DoctrineBridge] add support for the JSON type"

Author: nicolas-grekas

PropertyAccessor.php

@@ -470,7 +470,7 @@ private function readProperty(array $zval, string $property, bool $ignoreInvalid
                         throw $e;
                     }
                 } elseif (PropertyReadInfo::TYPE_PROPERTY === $type) {
-                    if (!method_exists($object, '__get') && !\array_key_exists($name, (array) $object) && (\PHP_VERSION_ID < 70400 || !(new \ReflectionProperty($class, $name))->hasType())) {
+                    if (!method_exists($object, '__get') && !isset($object->$name) && !\array_key_exists($name, (array) $object) && (\PHP_VERSION_ID < 70400 || !(new \ReflectionProperty($class, $name))->hasType())) {
                         throw new UninitializedPropertyException(sprintf('The property "%s::$%s" is not initialized.', $class, $name));
                     }