Bug in core Field.php?

[MarkE]

Not sure if I'm being silly, but it seems to me that the core Field::exportData (3.0.184) has a bug in the following two lines

$typeData = $this->type->exportConfigData($this, $data);
$data = array_merge($data, $typeData);

This code seems to cause the $typedata from the default fieldtype config settings to over-ride the actual field data. I have experienced a number of errors that appear to be caused by this. 
Shouldn't the 2nd line be this?

$data = array_merge($typeData, $data);

Per the PHP manual, the second array will overwrite the first if the keys match.
I have written a hook (before Fieldtype::exportConfigData) to fix this by merging the data the 'correct' way before returning it to Field::exportData. Effectively it performs the merge the other way around and returns the already merged array (see code at end). However, I'm concerned that this may have side effects where child classes call parent::___exportConfigData($field, $data). Assuming it is a bug, would I be better just hacking the core until it is fixed. I haven't raised a core issue before, so am a bit nervous about doing so (and would need some time to build a simple case to demonstrate the issue).

Code for hook is:

	public function afterExportConfigData(HookEvent $event) {
		$data = $event->arguments(0)->data;
		$value = $event->return;
		$event->return = array_merge($value, $data);
	}

 

[kongondo]

5 hours ago, MarkE said:

Per the PHP manual, the second array will overwrite the first if the keys match.

Only if the keys are strings ?...which they probably are in this case.