David Mandelberg wrote:

I think that would work. I was hoping to avoid sed, and I was thinking about
using shell's ${parameter#word} to strip and test for matching prefixes. But
I can't think of a way to do that with GIT_COMPLETION_IGNORE_CASE. Modern
bash has ${parameter@L} to lowercase a string, but I don't think the version
of bash on macos has that. With sed it would just be a matter of adding the
i flag if needed.

I haven't followed this discussion closely, but you can
also use ${parameter,,} to do parameter case modification.

Sadly, it looks like those were added in bash-4.0, so Apple
will have kept their users from benefiting from that to
avoid GPLv3 code. :/

I don't have an ancient bash-3.x like MacOS to test, but
maybe they've backported some features?

Though if you do end up using this, ${parameter,,} will work
in a much wider range of bash version that ${parameter@L}
which covers various releases in the OS's we aim to target
(e.g. RHEL 8.x, which has bash-4.4).

-- 
Todd