Selection + move line up/down = green highlight


I think this is a core issue:

As you can see, using ⌘+⌃+↑ or ⌘+⌃+↓ to move lines when you have a selection (within-line or multi-line) does the green highlight as if the ‘find next’ command had been executed on it. I can only assume this is a bug as I can’t think of a particularly good reason it’d be happening, but of course do let me know if it’s defined behaviour.