PHP 7.4 map_deep compatibility issue

[xknown]

​PHP 7.4 Backward Incompatible Changes mention the following change of behavior.

Calling get_object_vars() on an ArrayObject instance will now always return the properties of the ArrayObject itself (or a subclass). Previously it returned the values of the wrapped array/object unless the ArrayObject::STD_PROP_LIST flag was specified.

Code that depend on map_deep and pass instances of ArrayObject to this function doesn't work the same way when running it with PHP 7.4. We detected this while migrating code from PHP 7.3 to 7.4:

See the following simple example:
​https://3v4l.org/g3Xkj