lgtm but I would suggest waiting for @markj to approve as well

operator precedence

trim stray newlines

revert everything except the three places I commented

It's not trying to detect varargs support, it's trying to detect support for __attribute__((__format__)).

more thorough testing

avoid atexit

also tidy some tests

DIFF_EXIT is non-zero but not an error. Unless -s was specified, it is preceded by a message to stdout, and POSIX requires us to not only exit non-zero but also print an error message to stderr if writing to stdout fails. I suppose this would be clearer if I rewrote cmp to return non-error results back to main so there was only a single non-error exit point, and then try to fflush(stdout) iff !sflag, rather than use atexit().

style

man page tweaks

Update the manual page + error if -C or -P but no utility

Doh! The manual page had completely slipped my mind...

incorporate review feedback

Add test

lgtm with only cosmetic issues.

Sorry, I misread HAVE_STDARG_H as STDARG_H_INCLUDED which would indicate that <stdarg.h> has been included. This is even worse: it requires the caller to use something like autoconf and to explicitly check for the existence of <stdarg.h> which, again, is not needed to simply use libreadline.

Only if the translation unit that includes <readline/readline.h> also includes <stdarg.h>, which is required to define rl_message() since it uses va_start() etc but should not be required to merely call it.

Just noticed the second half of the patch...

Stefan, I highly recommend that you install freebsd-git-devtools and use git arc to prepare and stage reviews:

NOINET is also broken

Ah yes, you need to also not have ALTQ enabled, and in fact this patch is too simple because the module also fails to build with NOINET.

In D46876#1068845, @emaste wrote:

Is there value in keeping the tests that were added to the old version?

You also need to remove tools/build/options/WITH_GH_BC, move the relevant section of tools/build/mk/OptionalObsoleteFiles.inc to ObsoleteFiles.inc, and regenerate share/man/man5/src.conf.5.

@bapt thank you for the test cases, this gives me something to work towards.

In D44548#1068628, @ngie wrote:

Specifying this in the Makefile is significantly less code than doing it in the atf tests:

TEST_METADATA.lorder_test+=  required_programs="ar cc lorder nm"

This metadata ends up in the Kyuafile.