So, I noticed this:

$ env -i /bin/bash                 # Clear the environment
$ touch foo bar\ baz               # Creates two files, "foo" 
                                   # and "bar baz"
$ ls -1
'bar baz'
foo

Why is ls(1) suddenly quoting filenames that contain spaces? After a bit of digging, this commit introduced this change into GNU/coreutils, but at least Debian is on the case and fixed it in their version:

$ ls
bar baz
foo

$ ls --quoting-style=shell
'bar baz'
foo