git: support --list-cmds=list-<category>

This allows us to select any group of commands by a category defined
in command-list.txt. This is an internal/hidden option so we don't
have to be picky about the category name or worried about exposing too
much.

This will be used later by git-completion.bash to retrieve certain
command groups.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 7 insertions, 0 deletions

diff --git a/git.c b/git.c
index 10907f7266..4d5b8a9931 100644
--- a/git.c
+++ b/git.c
@@ -60,6 +60,13 @@ static int list_cmds(const char *spec)
 			list_all_main_cmds(&list);
 		else if (match_token(spec, len, "others"))
 			list_all_other_cmds(&list);
+		else if (len > 5 && !strncmp(spec, "list-", 5)) {
+			struct strbuf sb = STRBUF_INIT;
+
+			strbuf_add(&sb, spec + 5, len - 5);
+			list_cmds_by_category(&list, sb.buf);
+			strbuf_release(&sb);
+		}
 		else
 			die(_("unsupported command listing type '%s'"), spec);
 		spec += len;