Some readline functions can't be unbound with bind -u

[Eduardo Bustamante]

dualbus@debian:~/src/gnu/bash$ for fn in edit-and-execute-command
kill-line yank yank-pop; do echo $fn:; fn=$fn ./bash --noprofile
--norc -ic 'bind -q $fn; bind -u $fn; bind -q $fn'|sed 's/^/  /'; done
edit-and-execute-command:
  edit-and-execute-command can be invoked via "\C-x\C-e".
  edit-and-execute-command can be invoked via "\C-x\C-e".
kill-line:
  kill-line can be invoked via "\C-k".
  kill-line is not bound to any keys.
yank:
  yank can be invoked via "\C-y".
  yank is not bound to any keys.
yank-pop:
  yank-pop can be invoked via "\ey".
  yank-pop can be invoked via "\ey".

I was able to unbind edit-and-execute-command like this though:

dualbus@debian:~/src/gnu/bash$ fn=edit-and-execute-command ./bash
--noprofile --norc -ic 'bind -q $fn; bind -r "\C-x\C-e"; bind -q $fn'
edit-and-execute-command can be invoked via "\C-x\C-e".
edit-and-execute-command is not bound to any keys.

Which leads me to think that the former is a bug.