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

Stefan Beller [off-list ref] writes:

quoted

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.

I understand that.  What I was saying is that there may be no point
"reminding" them with René's "positivation" thing in effect and that
is why I asked you to try the simple two commands out to see if that
is the case.

I did that myself with "git commit --[no-]verify" and they are
indeed OK, so there is no reason to force developers to do this:

	int distim = 1; /* default is to distim */
	struct option options[] = {
		...
		OPT_BOOL(0, "distim", &distim, N_("distim")),
		...
	};
	...
	if (distim)
		do_the_distim_thing();

if/when the following is more natural in the context of the command:

	int no_distim = 1; /* default is to distim */
	struct option options[] = {
		...
		OPT_BOOL(0, "no-distim", &distim, N_("bypass distimming")),
		...
	};
	...
	if (distim)
		do_the_distim_thing();

whether it is inside -DDEVELOPER or not.