Confusion about Careful Spell

Hi everyone! I'm pretty new to DnD and have a question about the metamagic Careful Spell. 

Everywhere I read online, it says that Careful Spell doesn't fully protect allies, but automatically grants a number of allies a successful saving throw. So this would mean a spell like lightning bolt would still do half damage to any allies caught in the radius. However, the description of Careful Spell on my DnD Beyond Character sheet reads: 

"choose up to 5 creatures to automatically succeed on its saving throw, and it takes no damage if it would normally take half damage on a success."

The last part makes it sound like they wouldn't take any damage, as a successful saving throw for lightning bolt would normally do half damage on a success. 

Has this just been a recent change to Careful Spell? Or am I missing something and it would still damage allies? Any help appreciated :) 

Thank you! That makes a lot of sense.