m4/my_lib_readline: Fix check for additional libraries
authorMarkus Armbruster <armbru@pond.sub.org>
Tue, 29 Dec 2020 04:56:12 +0000 (05:56 +0100)
committerMarkus Armbruster <armbru@pond.sub.org>
Sat, 23 Jan 2021 06:08:21 +0000 (07:08 +0100)
commit55ff9cce0975f6cdd75922719d3d1653ea20c2ef
tree3926c11a83b2c66751fcfe3cb25e17e0468d4de1
parent55c1d29efec09a2fa3af67a95e922b8481e8728c
m4/my_lib_readline: Fix check for additional libraries

MY_LIB_READLINE tries each readline-compatible library with a sequence
of additional libraries, starting with none.  If the check with none
fails, all the others checks reuse the cached result, and also fail.
Broken in commit 1cbda2c7d "client: Rewrite readline configuration",
v4.4.0.

Avoid the unwanted chaching.

Signed-off-by: Markus Armbruster <armbru@pond.sub.org>
m4/my_lib_readline.m4