Commit 8baa643a3 (lineedit: match local directories when searching
PATH) included subdirectories of the current directory in the search
when tab-completing commands.
Unfortunately a short time later commit 1d180cd74 (lineedit: use
strncmp instead of is_prefixed_with (we know the length)) broke
thi
POSIX will be standardizing readlink (just the -n option) and realpath
(just -E and -e options):
https://www.austingroupbugs.net/view.php?id=1457
Change things for readlink so that the POSIX-mandated -n and -- work
even when disabling the non-standard (and partially non-working) -f
when FEATURE_RE
