Re: [PATCH v4 07/10] cat-file: fix remaining usage bugs

[John Cai <jcai@gitlab.com>]

> On Dec 8, 2021, at 7:34 AM, Ævar Arnfjörð Bjarmason <avarab@gmail.com> wrote:
> 
> With the migration of --batch-all-objects to OPT_CMDMODE() in the
> preceding commit one bug with combining it and other OPT_CMDMODE()
> options was solved, but we were still left with e.g. --buffer silently
> being discarded when not in batch mode.
> 
> Fix all those bugs, and in addition emit errors telling the user
> specifically what options can't be combined with what other options,
> before this we'd usually just emit the cryptic usage text and leave
> the users to work it out by themselves.
> 
> This change is rather large, because to do so we need to untangle the
> options processing so that we can not only error out, but emit
> sensible errors, and e.g. emit errors about options before errors
> about stray argc elements (as they might become valid if the option
> were removed).
> 
> Some of the output changes ("error:" to "fatal:" with
> usage_msg_opt[f]()), but none of the exit codes change, except in
> those cases where we silently accepted bad option combinations before,
> now we'll error out.
> 
> Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
> ---
> builtin/cat-file.c  | 95 ++++++++++++++++++++++++++++++---------------
> t/t1006-cat-file.sh | 41 +++++++++----------
> 2 files changed, 84 insertions(+), 52 deletions(-)
> 
> diff --git a/builtin/cat-file.c b/builtin/cat-file.c
> index 87356208134..1087f0f4a85 100644
> --- a/builtin/cat-file.c
> +++ b/builtin/cat-file.c
> @@ -648,6 +648,8 @@ static int batch_option_callback(const struct option *opt,
> int cmd_cat_file(int argc, const char **argv, const char *prefix)
> {
> 	int opt = 0;
> +	int opt_cw = 0;
> +	int opt_epts = 0;
> 	const char *exp_type = NULL, *obj_name = NULL;
> 	struct batch_options batch = {0};
> 	int unknown_type = 0;
> @@ -701,45 +703,74 @@ int cmd_cat_file(int argc, const char **argv, const char *prefix)
> 	batch.buffer_output = -1;
> 
> 	argc = parse_options(argc, argv, prefix, options, usage, 0);
> -	if (argc && batch.enabled)
> -		usage_with_options(usage, options);
> -	if (opt == 'b') {
> -		batch.all_objects = 1;
> -	} else if (opt) {
> -		if (batch.enabled && (opt == 'c' || opt == 'w'))
> -			batch.cmdmode = opt;
> -		else if (argc == 1)
> -			obj_name = argv[0];
> -		else
> -			usage_with_options(usage, options);
> -	} else if (!opt && !batch.enabled) {
> -		if (argc == 2) {
> -			exp_type = argv[0];
> -			obj_name = argv[1];
> -		} else
> -			usage_with_options(usage, options);
> -	} else if (batch.enabled && batch.cmdmode != opt)
> -		usage_with_options(usage, options);
> +	opt_cw = (opt == 'c' || opt == 'w');
> +	opt_epts = (opt == 'e' || opt == 'p' || opt == 't' || opt == 's');
> 
> -	if ((batch.follow_symlinks || batch.all_objects) && !batch.enabled) {
> -		usage_with_options(usage, options);
> -	}
> -
> -	if (force_path && opt != 'c' && opt != 'w') {
> -		error("--path=<path> needs --textconv or --filters");
> -		usage_with_options(usage, options);
> -	}
> +	/* --batch-all-objects? */
> +	if (opt == 'b')
> +		batch.all_objects = 1;
> 
> -	if (force_path && batch.enabled) {
> -		error("--path=<path> incompatible with --batch");
> -		usage_with_options(usage, options);
> -	}
> +	/* Option compatibility */
> +	if (force_path && !opt_cw)
> +		usage_msg_optf(_("'%s=<%s>' needs '%s' or '%s'"),
> +			       usage, options,
> +			       "--path", _("path|tree-ish"), "--filters",
> +			       "--textconv");
> 
> +	/* Option compatibility with batch mode */
> +	if (batch.enabled)
> +		;
> +	else if (batch.follow_symlinks)
> +		usage_msg_optf(_("'%s' requires a batch mode"), usage, options,
> +			       "--follow_symlinks");
> +	else if (batch.buffer_output >= 0)
> +		usage_msg_optf(_("'%s' requires a batch mode"), usage, options,
> +			       "--buffer");
> +	else if (batch.all_objects)
> +		usage_msg_optf(_("'%s' requires a batch mode"), usage, options,
> +			       "--batch-all_objects");

s/_/- for the last argument in the above usage_msg_optf calls

> +
> +	/* Batch defaults */
> 	if (batch.buffer_output < 0)
> 		batch.buffer_output = batch.all_objects;
> 
> -	if (batch.enabled)
> +	/* Return early if we're in batch mode? */
> +	if (batch.enabled) {
> +		if (opt_cw)
> +			batch.cmdmode = opt;
> +		else if (opt && opt != 'b')
> +			usage_msg_optf(_("'-%c' is incompatible with batch mode"),
> +				       usage, options, opt);
> +		else if (argc)
> +			usage_msg_opt(_("batch modes take no arguments"), usage,
> +				      options);
> +
> 		return batch_objects(&batch);
> +	}
> +
> +	if (opt) {
> +		if (!argc && opt == 'c')
> +			usage_msg_optf(_("<rev> required with '%s'"),
> +				       usage, options, "--textconv");
> +		else if (!argc && opt == 'w')
> +			usage_msg_optf(_("<rev> required with '%s'"),
> +				       usage, options, "--filters");
> +		else if (!argc && opt_epts)
> +			usage_msg_optf(_("<object> required with '-%c'"),
> +				       usage, options, opt);
> +		else if (argc == 1)
> +			obj_name = argv[0];
> +		else
> +			usage_msg_opt(_("too many arguments"), usage, options);
> +	} else if (!argc) {
> +		usage_with_options(usage, options);
> +	} else if (argc != 2) {
> +		usage_msg_optf(_("only two arguments allowed in <type> <object> mode, not %d"),
> +			      usage, options, argc);
> +	} else if (argc) {
> +		exp_type = argv[0];
> +		obj_name = argv[1];
> +	}
> 
> 	if (unknown_type && opt != 't' && opt != 's')
> 		die("git cat-file --allow-unknown-type: use with -s or -t");
> diff --git a/t/t1006-cat-file.sh b/t/t1006-cat-file.sh
> index ebec2061d25..123801cfe2a 100755
> --- a/t/t1006-cat-file.sh
> +++ b/t/t1006-cat-file.sh
> @@ -24,7 +24,7 @@ done
> 
> test_incompatible_usage () {
> 	test_expect_code 129 "$@" 2>err &&
> -	grep -E "^error:.**needs" err
> +	grep -E "^(fatal|error):.*(requires|incompatible with|needs)" err
> }
> 
> for opt in --batch --batch-check
> @@ -34,48 +34,54 @@ do
> 	'
> done
> 
> +test_missing_usage() {
> +	test_expect_code 129 "$@" 2>err &&
> +	grep -E "^fatal:.*required" err
> +}
> +
> short_modes="-e -p -t -s"
> cw_modes="--textconv --filters"
> 
> for opt in $cw_modes
> do
> 	test_expect_success "usage: $opt requires another option" '
> -		test_expect_code 129 git cat-file $opt
> +		test_missing_usage git cat-file $opt
> 	'
> done
> 
> for opt in $short_modes
> do
> 	test_expect_success "usage: $opt requires another option" '
> -		test_expect_code 129 git cat-file $opt
> +		test_missing_usage git cat-file $opt
> 	'
> 
> 	for opt2 in --batch \
> 		--batch-check \
> -		--follow-symlinks
> +		--follow-symlinks \
> +		"--path=foo HEAD:some-path.txt"
> 	do
> -		test_expect_failure "usage: incompatible options: $opt and $opt2" '
> +		test_expect_success "usage: incompatible options: $opt and $opt2" '
> 			test_incompatible_usage git cat-file $opt $opt2
> 		'
> 	done
> -
> -	opt2="--path=foo HEAD:some-path.txt"
> -	test_expect_success "usage: incompatible options: $opt and $opt2" '
> -		test_incompatible_usage git cat-file $opt $opt2
> -	'
> done
> 
> +test_too_many_arguments() {
> +	test_expect_code 129 "$@" 2>err &&
> +	grep -E "^fatal: too many arguments$" err
> +}
> +
> for opt in $short_modes $cw_modes
> do
> 	args="one two three"
> 	test_expect_success "usage: too many arguments: $opt $args" '
> -		test_expect_code 129 git cat-file $opt $args
> +		test_too_many_arguments git cat-file $opt $args
> 	'
> 
> 	for opt2 in --buffer --follow-symlinks
> 	do
> 		test_expect_success "usage: incompatible arguments: $opt with batch option $opt2" '
> -			test_expect_code 129 git cat-file $opt $opt2
> +			test_incompatible_usage git cat-file $opt $opt2
> 		'
> 	done
> done
> @@ -84,14 +90,9 @@ for opt in --buffer \
> 	--follow-symlinks \
> 	--batch-all-objects
> do
> -	status=success
> -	if test $opt = "--buffer"
> -	then
> -		status=failure
> -	fi
> -	test_expect_$status "usage: bad option combination: $opt without batch mode" '
> -		test_expect_code 129 git cat-file $opt &&
> -		test_expect_code 129 git cat-file $opt commit HEAD
> +	test_expect_success "usage: bad option combination: $opt without batch mode" '
> +		test_incompatible_usage git cat-file $opt &&
> +		test_incompatible_usage git cat-file $opt commit HEAD
> 	'
> done
> 
> -- 
> 2.34.1.926.g895e15e0c0c
>