minor #19922 [PropertyAccess] __isset() returns true only if values are present (xabbuh)

This PR was merged into the 5.4 branch.

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[PropertyAccess] __isset() returns true only if values are present

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aa42227 __isset() returns true only if values are present

Author: javiereguiluz

components/property_access.rst

@@ -207,7 +207,7 @@ The ``getValue()`` method can also use the magic ``__get()`` method::
 
         public function __isset($id): bool
         {
-            return true;
+            return array_key_exists($id, $this->children);
         }
     }