As a part of his "Advent Contribution" series Derick Rethans has posted about an update to XDebug that fixes a bug reported around hidden properties.
This first contribution is for bug #987: "Hidden property names not shown". In PHP it is possible to convert an array to an object. [...] Xdebug's standard HTML var_dump() as well as the CLI, the coloured CLI and the debugger interface DBGp all suffered from the same issues that numerical properties were not showing in output.
With the committed fix the output of the var_dump now shows these special property names with curly braces around them and makes them available via the property_get method. If you're interested in the actual commit, you can check it out here.