Bash _/- completion

Question

man bash says:

completion-map-case (Off)

If set to On, and completion-ignore-case is enabled, readline treats hyphens (-) and underscores (_) as equivalent when performing case-insensitive filename matching and completion.

$ bind -v|grep case
set completion-ignore-case on
set completion-map-case on

When I type

$ touch _test
$ chmod +x -t<TAB>

it completes to

$ chmod +x _test

But neither

$ ./-t<TAB>
$ ls -t<TAB>

complete.

Why is that and can it be fixed?

Answer 1

Chet Ramey replied to my report:

Thanks for the report. Those two options work for filename completion, but not command completion (the bulk of which is handled outside readline). I'll take a look at exposing that functionality outside readline, since it's currently part of readline's filename completion, but that will take some time and probably require a version bump.