There was a change in ls which caused it to quote file names with spaces or special characters instead of (I think?) escaping them. Some people were upset because they considered this a breaking change. I'll just add that ls only does this if it's running interactively so I wouldn't expect it to break scripts.
I'm a little surprised people are using ls in scripts. I'm normally using find, with the mill separator to deal with spaces in filenames.
... null separator ...
I thought I proof-read that sentence when I wrote it...