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

On Tue, Sep 5, 2017 at 8:16 PM, Junio C Hamano [off-list ref] wrote:

Junio C Hamano [off-list ref] writes:

quoted

Stefan Beller [off-list ref] writes:

quoted

  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.

quoted

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.

As far as the code is concerned it is only inside the -DDEVELOPER ?
The intent of this patch is to have a developers aid to remind them
that too many negations might be a sign of trouble.

Thanks,
Stefan

Thanks.