|mediawiki/extensions/VisualEditor : master||Fix parsing of external links, now Parsoid adds 'external' classes|
Ideally, Parsoid shouldn't have to account for these since we cannot be trying to add adaptors based on different editing clients. So, VE should stripping out the mw:NumberedLink changes before sending it back to Parsoid.
It looks like these were still serving a purpose, as when we write to the clipboard we want to (1) add some text ("") to avoid the link being removed and the give some text if pasted into an external editor, but (2) preserve the numbered link status if pasted into VE. As detection of numbered links is based on looking for empty tags, we have to add another attribute to avoid adding text breaking the conversion.
However we can ensure this is only done in clipboard conversion mode, and never sent to Parsoid.