[PATCH v3 0/6] commit-graph: usage fixes

Fixes hopefully all the comments on v2[1], thanks Andrei and Taylor.

There's now a small mid-series digression before to also refactor the "early exit to "usage" on !argc" for the multi-pack-index.

Taylor suggested using braces for the "else" so maybe he won't like it :)

I figured having the two similar commands use the same pattern was worth the digression.

1. http://lore.kernel.org/git/cover-0.5-00000000000-20210718T074936Z-avarab@gmail.com

Ævar Arnfjörð Bjarmason (6):
  commit-graph: define common usage with a macro
  commit-graph: remove redundant handling of -h
  commit-graph: use parse_options_concat()
  multi-pack-index: refactor "goto usage" pattern
  commit-graph: early exit to "usage" on !argc
  commit-graph: show usage on "commit-graph [write|verify] garbage"

 builtin/commit-graph.c     | 95 +++++++++++++++++++++-----------------
 builtin/multi-pack-index.c | 11 ++---
 t/t5318-commit-graph.sh    |  5 ++
 3 files changed, 63 insertions(+), 48 deletions(-)

Range-diff against v2:
1:  ee6630b7c0d ! 1:  1b9b4703ce2 commit-graph: define common usage with a macro
    @@ builtin/commit-graph.c
     -	   "[--split[=<strategy>]] [--reachable|--stdin-packs|--stdin-commits] "
     -	   "[--changed-paths] [--[no-]max-new-filters <n>] [--[no-]progress] "
     -	   "<split options>"),
    -+static const char * builtin_commit_graph_verify_usage[] = {
     +#define BUILTIN_COMMIT_GRAPH_VERIFY_USAGE \
     +	N_("git commit-graph verify [--object-dir <objdir>] [--shallow] [--[no-]progress]")
    ++
    ++#define BUILTIN_COMMIT_GRAPH_WRITE_USAGE \
    ++	N_("git commit-graph write [--object-dir <objdir>] [--append] " \
    ++	   "[--split[=<strategy>]] [--reachable|--stdin-packs|--stdin-commits] " \
    ++	   "[--changed-paths] [--[no-]max-new-filters <n>] [--[no-]progress] " \
    ++	   "<split options>")
    ++
    ++static const char * builtin_commit_graph_verify_usage[] = {
     +	BUILTIN_COMMIT_GRAPH_VERIFY_USAGE,
      	NULL
      };
    @@ builtin/commit-graph.c
     -static const char * const builtin_commit_graph_verify_usage[] = {
     -	N_("git commit-graph verify [--object-dir <objdir>] [--shallow] [--[no-]progress]"),
     +static const char * builtin_commit_graph_write_usage[] = {
    -+#define BUILTIN_COMMIT_GRAPH_WRITE_USAGE \
    -+	N_("git commit-graph write [--object-dir <objdir>] [--append] " \
    -+	   "[--split[=<strategy>]] [--reachable|--stdin-packs|--stdin-commits] " \
    -+	   "[--changed-paths] [--[no-]max-new-filters <n>] [--[no-]progress] " \
    -+	   "<split options>")
     +	BUILTIN_COMMIT_GRAPH_WRITE_USAGE,
      	NULL
      };
2:  03581d85781 ! 2:  8f50750ae5e commit-graph: remove redundant handling of -h
    @@ Commit message
         parse_options() did this at the time, and the commit-graph code never
         used PARSE_OPT_NO_INTERNAL_HELP.
     
    +    We don't need a test for this, it's tested by the t0012-help.sh test
    +    added in d691551192a (t0012: test "-h" with builtins, 2017-05-30).
    +
         Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
     
      ## builtin/commit-graph.c ##
    @@ builtin/commit-graph.c: int cmd_commit_graph(int argc, const char **argv, const
      	git_config(git_default_config, NULL);
      	argc = parse_options(argc, argv, prefix,
      			     builtin_commit_graph_options,
    -
    - ## t/t5318-commit-graph.sh ##
    -@@ t/t5318-commit-graph.sh: test_description='commit graph'
    - 
    - GIT_TEST_COMMIT_GRAPH_CHANGED_PATHS=0
    - 
    -+test_expect_success 'usage' '
    -+	test_expect_code 129 git commit-graph -h 2>err &&
    -+	! grep error: err
    -+'
    -+
    - test_expect_success 'setup full repo' '
    - 	mkdir full &&
    - 	cd "$TRASH_DIRECTORY/full" &&
3:  8e909cd9c23 ! 3:  f02da994363 commit-graph: use parse_options_concat()
    @@ Commit message
         commit-graph: use parse_options_concat()
     
         Make use of the parse_options_concat() so we don't need to copy/paste
    -    common options like --object-dir. This is inspired by a similar change
    -    to "checkout" in 2087182272
    -    (checkout: split options[] array in three pieces, 2019-03-29).
    +    common options like --object-dir.
    +
    +    This is inspired by a similar change to "checkout" in 2087182272
    +    (checkout: split options[] array in three pieces, 2019-03-29), and the
    +    same pattern in the multi-pack-index command, see
    +    60ca94769ce (builtin/multi-pack-index.c: split sub-commands,
    +    2021-03-30).
     
         A minor behavior change here is that now we're going to list both
         --object-dir and --progress first, before we'd list --progress along
         with other options.
     
    +    Co-authored-by: Taylor Blau <me@ttaylorr.com>
         Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
     
      ## builtin/commit-graph.c ##
    @@ builtin/commit-graph.c: static struct opts_commit_graph {
      	int enable_changed_paths;
      } opts;
      
    -+static struct option *add_common_options(struct option *prevopts)
    ++static struct option common_opts[] = {
    ++	OPT_STRING(0, "object-dir", &opts.obj_dir,
    ++		   N_("dir"),
    ++		   N_("the object directory to store the graph")),
    ++	OPT_BOOL(0, "progress", &opts.progress,
    ++		 N_("force progress reporting")),
    ++	OPT_END()
    ++};
    ++
    ++static struct option *add_common_options(struct option *to)
     +{
    -+	struct option options[] = {
    -+		OPT_STRING(0, "object-dir", &opts.obj_dir,
    -+			   N_("dir"),
    -+			   N_("the object directory to store the graph")),
    -+		OPT_BOOL(0, "progress", &opts.progress,
    -+			 N_("force progress reporting")),
    -+		OPT_END()
    -+	};
    -+	struct option *newopts = parse_options_concat(options, prevopts);
    -+	free(prevopts);
    -+	return newopts;
    ++	return parse_options_concat(common_opts, to);
     +}
     +
      static struct object_directory *find_odb(struct repository *r,
    @@ builtin/commit-graph.c: static int graph_verify(int argc, const char **argv)
     -		OPT_BOOL(0, "progress", &opts.progress, N_("force progress reporting")),
      		OPT_END(),
      	};
    -+	struct option *options = parse_options_dup(builtin_commit_graph_verify_options);
    -+	options = add_common_options(options);
    ++	struct option *options = add_common_options(builtin_commit_graph_verify_options);
      
      	trace2_cmd_mode("verify");
      
    @@ builtin/commit-graph.c: static int graph_verify(int argc, const char **argv)
      			     builtin_commit_graph_verify_usage, 0);
      
      	if (!opts.obj_dir)
    +@@ builtin/commit-graph.c: static int graph_verify(int argc, const char **argv)
    + 		die_errno(_("Could not open commit-graph '%s'"), graph_name);
    + 
    + 	FREE_AND_NULL(graph_name);
    ++	FREE_AND_NULL(options);
    + 
    + 	if (open_ok)
    + 		graph = load_commit_graph_one_fd_st(the_repository, fd, &st, odb);
     @@ builtin/commit-graph.c: static int graph_write(int argc, const char **argv)
      	struct progress *progress = NULL;
      
    @@ builtin/commit-graph.c: static int graph_write(int argc, const char **argv)
      			0, write_option_max_new_filters),
      		OPT_END(),
      	};
    -+	struct option *options = parse_options_dup(builtin_commit_graph_write_options);
    -+	options = add_common_options(options);
    ++	struct option *options = add_common_options(builtin_commit_graph_write_options);
      
      	opts.progress = isatty(2);
      	opts.enable_changed_paths = -1;
    @@ builtin/commit-graph.c: static int graph_write(int argc, const char **argv)
      
      	if (opts.reachable + opts.stdin_packs + opts.stdin_commits > 1)
     @@ builtin/commit-graph.c: static int graph_write(int argc, const char **argv)
    + 		result = 1;
    + 
    + cleanup:
    ++	FREE_AND_NULL(options);
    + 	string_list_clear(&pack_indexes, 0);
    + 	strbuf_release(&buf);
    + 	return result;
    +@@ builtin/commit-graph.c: static int graph_write(int argc, const char **argv)
      
      int cmd_commit_graph(int argc, const char **argv, const char *prefix)
      {
    @@ builtin/commit-graph.c: static int graph_write(int argc, const char **argv)
     -			N_("the object directory to store the graph")),
     -		OPT_END(),
     -	};
    -+	struct option *no_options = parse_options_dup(NULL);
    -+	struct option *builtin_commit_graph_options = add_common_options(no_options);
    ++	struct option *builtin_commit_graph_options = common_opts;
      
      	git_config(git_default_config, NULL);
      	argc = parse_options(argc, argv, prefix,
-:  ----------- > 4:  6e9bd877866 multi-pack-index: refactor "goto usage" pattern
4:  6801fb18faa = 5:  7acb4bd75ce commit-graph: early exit to "usage" on !argc
5:  5c96699496b ! 6:  5c1694e071e commit-graph: show usage on "commit-graph [write|verify] garbage"
    @@ builtin/commit-graph.c: static int graph_write(int argc, const char **argv)
      		die(_("use at most one of --reachable, --stdin-commits, or --stdin-packs"));
     
      ## t/t5318-commit-graph.sh ##
    -@@ t/t5318-commit-graph.sh: GIT_TEST_COMMIT_GRAPH_CHANGED_PATHS=0
    +@@ t/t5318-commit-graph.sh: test_description='commit graph'
      
    - test_expect_success 'usage' '
    - 	test_expect_code 129 git commit-graph -h 2>err &&
    --	! grep error: err
    -+	! grep error: err &&
    + GIT_TEST_COMMIT_GRAPH_CHANGED_PATHS=0
    + 
    ++test_expect_success 'usage' '
     +	test_expect_code 129 git commit-graph write blah &&
     +	test_expect_code 129 git commit-graph write verify
    - '
    - 
    ++'
    ++
      test_expect_success 'setup full repo' '
    + 	mkdir full &&
    + 	cd "$TRASH_DIRECTORY/full" &&