Re: [PATCH v2] parse-options: don't emit "ambiguous option" for aliases

[Duy Nguyen <pclouds@gmail.com>]

On Wed, Apr 17, 2019 at 7:44 PM Ævar Arnfjörð Bjarmason
<avarab@gmail.com> wrote:
>
> Change the option parsing machinery so that e.g. "clone --recurs ..."
> doesn't error out because "clone" understands both "--recursive" and
> "--recurse-submodules" to mean the same thing.
>
> Initially "clone" just understood --recursive until the
> --recurses-submodules alias was added in ccdd3da652 ("clone: Add the
> --recurse-submodules option as alias for --recursive",
> 2010-11-04). Since bb62e0a99f ("clone: teach --recurse-submodules to
> optionally take a pathspec", 2017-03-17) the longer form has been
> promoted to the default.
>
> But due to the way the options parsing machinery works this resulted
> in the rather absurd situation of:
>
>     $ git clone --recurs [...]
>     error: ambiguous option: recurs (could be --recursive or --recurse-submodules)
>
> Let's re-use the PARSE_OPT_NOCOMPLETE flag to mean "this option
> doesn't contribute to abbreviation ambiguity". I was going to add a
> new PARSE_OPT_NOABBREV flag, but it makes sense just to re-use
> PARSE_OPT_NOCOMPLETE.
>
> Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
> ---
>
> See
> https://public-inbox.org/git/20190325202329.26033-1-avarab@gmail.com/
> for v1. There wasn't consensus for 1/2 there, but this used-to-be 2/2
> seems like a no-brainer bugfix.
>
> It conflicted with some recently-landed stuff in 'master', but now
> cleanly applies to it and 'pu', and with pu's
> GIT_TEST_DISALLOW_ABBREVIATED_OPTIONS.
>
>  builtin/clone.c          | 4 ++--
>  parse-options.c          | 3 ++-
>  parse-options.h          | 2 ++
>  t/t0040-parse-options.sh | 5 +++++
>  4 files changed, 11 insertions(+), 3 deletions(-)
>
> diff --git a/builtin/clone.c b/builtin/clone.c
> index 50bde99618..4dc26969a7 100644
> --- a/builtin/clone.c
> +++ b/builtin/clone.c
> @@ -100,8 +100,8 @@ static struct option builtin_clone_options[] = {
>                     N_("setup as shared repository")),
>         { OPTION_CALLBACK, 0, "recursive", &option_recurse_submodules,
>           N_("pathspec"), N_("initialize submodules in the clone"),
> -         PARSE_OPT_OPTARG | PARSE_OPT_HIDDEN, recurse_submodules_cb,
> -         (intptr_t)"." },
> +         PARSE_OPT_OPTARG | PARSE_OPT_HIDDEN | PARSE_OPT_NOCOMPLETE,

What happens if someone adds --recursive-hard? --recursi then
resolving to --recursive-hard sounds wrong.

But on the other hand I can see it's a bit more work to teach
parse-options OPT_ALIAS to say "--recursive is just an alias of
--recurse-submodules" and chances of --recursive-hard coming up are
probably very low.

So I don't know but I thought I should point out.

> +         recurse_submodules_cb, (intptr_t)"." },
>         { OPTION_CALLBACK, 0, "recurse-submodules", &option_recurse_submodules,
>           N_("pathspec"), N_("initialize submodules in the clone"),
>           PARSE_OPT_OPTARG, recurse_submodules_cb, (intptr_t)"." },
> diff --git a/parse-options.c b/parse-options.c
> index cec74522e5..9899ce0171 100644
> --- a/parse-options.c
> +++ b/parse-options.c
> @@ -292,7 +292,8 @@ static enum parse_opt_result parse_long_opt(
>                 if (!rest) {
>                         /* abbreviated? */
>                         if (!(p->flags & PARSE_OPT_KEEP_UNKNOWN) &&
> -                           !strncmp(long_name, arg, arg_end - arg)) {
> +                           !strncmp(long_name, arg, arg_end - arg) &&
> +                           !(options->flags & PARSE_OPT_NOCOMPLETE)) {
>  is_abbreviated:
>                                 if (abbrev_option) {
>                                         /*
> diff --git a/parse-options.h b/parse-options.h
> index 74cce4e7fc..51c4b71ab0 100644
> --- a/parse-options.h
> +++ b/parse-options.h
> @@ -96,6 +96,8 @@ typedef enum parse_opt_result parse_opt_ll_cb(struct parse_opt_ctx_t *ctx,
>   *                             Useful for options with multiple parameters.
>   *   PARSE_OPT_NOCOMPLETE: by default all visible options are completable
>   *                        by git-completion.bash. This option suppresses that.
> + *                        Will also skip this option when abbreviation is
> + *                        considered.
>   *   PARSE_OPT_COMP_ARG: this option forces to git-completion.bash to
>   *                      complete an option as --name= not --name even if
>   *                      the option takes optional argument.
> diff --git a/t/t0040-parse-options.sh b/t/t0040-parse-options.sh
> index b8f366c442..e8f0371830 100755
> --- a/t/t0040-parse-options.sh
> +++ b/t/t0040-parse-options.sh
> @@ -220,6 +220,11 @@ test_expect_success 'non ambiguous option (after two options it abbreviates)' '
>         test-tool parse-options --expect="string: 123" --st 123
>  '
>
> +test_expect_success 'NOCOMPLETE options do not contribute to abbreviation' '
> +       test_when_finished "rm -rf A" &&
> +       git clone --recurs . A
> +'
> +
>  cat >typo.err <<\EOF
>  error: did you mean `--boolean` (with two dashes ?)
>  EOF
> --
> 2.21.0.593.g511ec345e18
>


-- 
Duy