[PATCH v5 05/10] git.c: convert --list-*builtins to --list-cmds=*

[Nguyễn Thái Ngọc Duy]

Even if these are hidden options, let's make them a bit more generic
since we're introducing more listing types shortly.

This also allows combining multiple listing types, which is usually
now (for combining parseopt and builtins) but future types will
benefit from this.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclo...@gmail.com>
---
 contrib/completion/git-completion.bash |  2 +-
 git.c                                  | 27 ++++++++++++++++++++------
 t/t0012-help.sh                        |  2 +-
 3 files changed, 23 insertions(+), 8 deletions(-)

diff --git a/contrib/completion/git-completion.bash 
b/contrib/completion/git-completion.bash
index 01dd9ff07a..d7b448fd94 100644
--- a/contrib/completion/git-completion.bash
+++ b/contrib/completion/git-completion.bash
@@ -3044,7 +3044,7 @@ __git_complete_common () {
 __git_cmds_with_parseopt_helper=
 __git_support_parseopt_helper () {
        test -n "$__git_cmds_with_parseopt_helper" ||
-               __git_cmds_with_parseopt_helper="$(__git 
--list-parseopt-builtins)"
+               __git_cmds_with_parseopt_helper="$(__git --list-cmds=parseopt)"
 
        case " $__git_cmds_with_parseopt_helper " in
        *" $1 "*)
diff --git a/git.c b/git.c
index f598fae7b7..ea9bbfb6a3 100644
--- a/git.c
+++ b/git.c
@@ -38,6 +38,25 @@ static int use_pager = -1;
 
 static void list_builtins(unsigned int exclude_option, char sep);
 
+static int list_cmds(const char *spec)
+{
+       while (*spec) {
+               const char *sep = strchrnul(spec, ',');
+               int len = sep - spec;
+
+               if (len == 8 && !strncmp(spec, "builtins", 8))
+                       list_builtins(0, '\n');
+               else if (len == 8 && !strncmp(spec, "parseopt", 8))
+                       list_builtins(NO_PARSEOPT, ' ');
+               else
+                       die(_("unsupported command listing type '%s'"), spec);
+               spec += len;
+               if (*spec == ',')
+                       spec++;
+       }
+       return 0;
+}
+
 static void commit_pager_choice(void) {
        switch (use_pager) {
        case 0:
@@ -223,12 +242,8 @@ static int handle_options(const char ***argv, int *argc, 
int *envchanged)
                        }
                        (*argv)++;
                        (*argc)--;
-               } else if (!strcmp(cmd, "--list-builtins")) {
-                       list_builtins(0, '\n');
-                       exit(0);
-               } else if (!strcmp(cmd, "--list-parseopt-builtins")) {
-                       list_builtins(NO_PARSEOPT, ' ');
-                       exit(0);
+               } else if (skip_prefix(cmd, "--list-cmds=", &cmd)) {
+                       exit(list_cmds(cmd));
                } else {
                        fprintf(stderr, _("unknown option: %s\n"), cmd);
                        usage(git_usage_string);
diff --git a/t/t0012-help.sh b/t/t0012-help.sh
index c096f33505..3c91a9024a 100755
--- a/t/t0012-help.sh
+++ b/t/t0012-help.sh
@@ -59,7 +59,7 @@ test_expect_success 'git help' '
 '
 
 test_expect_success 'generate builtin list' '
-       git --list-builtins >builtins
+       git --list-cmds=builtins >builtins
 '
 
 while read builtin
-- 
2.17.0.664.g8924eee37a