Re: [PATCH] parse-options: warn developers on negated options

From: Junio C Hamano <gitster@pobox.com>
Date: Sep 6, 2017, 03:16 UTC
Message-ID: <xmqqzia88qkj.fsf@gitster.mtv.corp.google.com>
In-Reply-To: <xmqq8thsa901.fsf@gitster.mtv.corp.google.com>

Junio C Hamano <gitster@pobox.com> writes:

Show 13 quoted lines

> Stefan Beller <sbeller@google.com> writes:
>
>>   This patch disallows all no- options, but we could be more open and allow
>>   --no-options that have the NO_NEG bit set.
>
> "--no-foo" that does not take "--foo" is perhaps OK so should not
> trigger an error.
>
> A ("--no-foo", "--foo") pair is better spelled as ("--foo",
> "--no-foo") pair whose default is "--foo", but making it an error is
> probably a bit too much.
>
> Compared to that, ("--no-foo", "--no-no-foo") pair feels nonsense.

Ahh, I was an idiot (call it vacation-induced-brain-disfunction). I forgot about 0f1930c5 ("parse-options: allow positivation of options starting, with no-", 2012-02-25), which may have already made your new use of "--no-verify" in builtin/merge.c and existing one in commit.c OK long time ago. A quick check to see how your version of

	git merge --verify
	git merge --no-verify

behaves with respect to the commit-msg hook is veriy much appreciated, as my tree is in no shape to apply and try a patch while trying to absorb the patches sent to the list the past week.

Thanks, and sorry for a possible false alarm.

Show 9 quoted lines

> Having said that, because the existing parse_options_check() is all
> about catching the programming mistake (the end user cannot fix an
> error from it by tweaking the command line option s/he gives to the
> program), I do not think a conditional compilation like you added
> mixes well.  Either make the whole thing, not just your new test,
> conditional to -DDEVELOPER (which would make it possible for you to
> build and ship a binary with broken options[] array to the end-users
> that does not die in this function), which is undesirable, or add a
> new test that catches a definite error unconditionally.

This part still is valid. If René's work 2 years ago is sufficient to address "--no-foo" thing, then there is nothing we need to add to this test, but if we later need to add new sanity check, we should add it without -DDEVELOPER, or we should make the whole thing inside it.

Thanks.