[RFC PATCH] parse-options: disallow double-negations of options starting with no-
- From
Jacob Keller <jacob.e.keller@intel.com>
- Date
- Apr 19, 2017, 09:08 UTC
- Message-ID
- <20170419090820.20279-1-jacob.e.keller@intel.com>
From: Jacob Keller <jacob.keller@gmail.com>
Many options can be negated by prefixing the option with "no-", for example "--3way" can be prefixed with "--no-3way" to disable it. Since 0f1930c58754 ("parse-options: allow positivation of options starting, with no-", 2012-02-25) we have also had support to negate options which start with "no-" by using the positive wording.
This leads to the confusing (and non-documented) case that you can still prefix options beginning with "no-" by a second "no-" to negate them. That is, we allow "no-no-hardlinks" to negate the "no-hardlinks" option.
This can be confusing to the user so lets just disallow the double-negative forms. If the long_name begins with "no-" then we simply don't allow the regular negation format, and only allow the option to be negated by the positive form.
Signed-off-by: Jacob Keller <jacob.keller@gmail.com> --- I started going about implementing an OPT_NEGBOOL as suggested by Peff, but realized this might just be simpler, and we already support the positive format for the negation, so we don't lose expressiveness. We *might* want to tie this to an option flag instead so that it only kicks in if the option specifically requests it. Thoughts?
parse-options.c | 3 +++ t/t0040-parse-options.sh | 5 ++++- 2 files changed, 7 insertions(+), 1 deletion(-)
diff --git a/parse-options.c b/parse-options.c index a23a1e67f04f..8e024c569f52 100644 --- a/parse-options.c +++ b/parse-options.c @@ -299,6 +299,9 @@ static int parse_long_opt(struct parse_opt_ctx_t *p, const char *arg, } continue; } + /* avoid double-negate on long_name */ + if (starts_with(long_name, "no-")) + continue; flags |= OPT_UNSET; if (!skip_prefix(arg + 3, long_name, &rest)) { /* abbreviated and negated? */ diff --git a/t/t0040-parse-options.sh b/t/t0040-parse-options.sh index 74d2cd76fe56..abccfa5f265f 100755 --- a/t/t0040-parse-options.sh +++ b/t/t0040-parse-options.sh @@ -88,7 +88,6 @@ test_expect_success 'OPT_BOOL() is idempotent #1' 'check boolean: 1 --yes --yes' test_expect_success 'OPT_BOOL() is idempotent #2' 'check boolean: 1 -DB' test_expect_success 'OPT_BOOL() negation #1' 'check boolean: 0 -D --no-yes' -test_expect_success 'OPT_BOOL() negation #2' 'check boolean: 0 -D --no-no-doubt' test_expect_success 'OPT_BOOL() no negation #1' 'check_unknown_i18n --fear' test_expect_success 'OPT_BOOL() no negation #2' 'check_unknown_i18n --no-no-fear' @@ -392,4 +391,8 @@ test_expect_success '--no-verbose resets multiple verbose to 0' ' test-parse-options --expect="verbose: 0" -v -v -v --no-verbose ' +test_expect_success 'double negation not accepted' ' + test_must_fail test-parse-options --expect="boolean: 0" --no-no-doubt +' + test_done
-- 2.12.2.882.g942b4cedeff1.dirty