Warning: preg_match() expects parameter 2 to be string, array given in DumperPluginManager.php on line 87

It appears that fixDumperFieldIncompatibility method is causing a warning:

Warning: preg_match() expects parameter 2 to be string, array given in DumperPluginManager.php on line 87

On inspecting the value of $dumper_result, this is what it contains for me:

Array
(
    [lat] => <REDACTED>
    [lng] => <REDACTED>
    [lat_sin] => <REDACTED>
    [lat_cos] => <REDACTED>
    [lng_rad] => <REDACTED>
    [data] => Array
        (
            [streetNumber] => <REDACTED>
            [streetName] => <REDACTED>
            [postalCode] => <REDACTED>
            [locality] => 
            [subLocality] => 
            [adminLevels] => Array
                (
                    [1] => Array
                        (
                            [name] => England
                            [code] => England
                        )

                    [2] => Array
                        (
                            [name] => <REDACTED>
                            [code] => <REDACTED>
                        )

                )

            [country] => United Kingdom
            [countryCode] => GB
            [timezone] => 
        )

)

I'm geocoding from an address field. I've created a patch so I can geocode my addresses but I suspect this might not be entirely suitable for all cases. I've not really fully grokked the code for this module so not entirely sure under what circumstances only a string would appear in the $dumper_results variable.