rawhide turns off the internal ls by default.

Also, unless I'm misinterpreting the RFCs, ftp ls isn't supposed to show
dotfiles unless you run ls -a, just like a shell.

From file /usr/doc/wu-ftpd-2.6.0/CHANGES:

 o  The internal ls (see below) was judged to be unready.  It has been disabled
    by default but can be enabled with a compile-time option for those who wish
    to attempt to debug it (be warned, it has a lot of problems).

Internal ls is enable even the file claims vice versa. 

Added following lines to /etc/ftpaccess, which should (?) enable external ls,
but it didn't help:

lsplain ls -a
lslong ls -a
lsplain ls -a                                                                   

Dot-files are still hidden...

The internal ls is definitely disabled in rawhide, and besides it's not as bad
as the release notes claim (we've added some fixes).

I checked it by using strace and it does not run /bin/ls.  No change if I have
line 'lsplain ls -a' in /etc/ftpaccess.

Wu-ftpd version is 2.6.0-14.6x

2.6.0-14.6x is not the version bero referred to; that is the errata version.  It
has internal ls enabled.

2.6.1-6 from Rawhide does not have internal ls.