merge(third_party/git): Merge squashed git subtree at v2.23.0 r/373

Merge commit '1b593e1ea4d2af0f6444d9a7788d5d99abd6fde5' as 'third_party/git'

1 files changed, 892 insertions, 0 deletions

diff --git a/third_party/git/git.c b/third_party/git/git.c
new file mode 100644
index 000000000000..c1ee7124edcf
--- /dev/null
+++ b/third_party/git/git.c
@@ -0,0 +1,892 @@
+#include "builtin.h"
+#include "config.h"
+#include "exec-cmd.h"
+#include "help.h"
+#include "run-command.h"
+#include "alias.h"
+
+#define RUN_SETUP		(1<<0)
+#define RUN_SETUP_GENTLY	(1<<1)
+#define USE_PAGER		(1<<2)
+/*
+ * require working tree to be present -- anything uses this needs
+ * RUN_SETUP for reading from the configuration file.
+ */
+#define NEED_WORK_TREE		(1<<3)
+#define SUPPORT_SUPER_PREFIX	(1<<4)
+#define DELAY_PAGER_CONFIG	(1<<5)
+#define NO_PARSEOPT		(1<<6) /* parse-options is not used */
+
+struct cmd_struct {
+	const char *cmd;
+	int (*fn)(int, const char **, const char *);
+	unsigned int option;
+};
+
+const char git_usage_string[] =
+	N_("git [--version] [--help] [-C <path>] [-c <name>=<value>]\n"
+	   "           [--exec-path[=<path>]] [--html-path] [--man-path] [--info-path]\n"
+	   "           [-p | --paginate | -P | --no-pager] [--no-replace-objects] [--bare]\n"
+	   "           [--git-dir=<path>] [--work-tree=<path>] [--namespace=<name>]\n"
+	   "           <command> [<args>]");
+
+const char git_more_info_string[] =
+	N_("'git help -a' and 'git help -g' list available subcommands and some\n"
+	   "concept guides. See 'git help <command>' or 'git help <concept>'\n"
+	   "to read about a specific subcommand or concept.\n"
+	   "See 'git help git' for an overview of the system.");
+
+static int use_pager = -1;
+
+static void list_builtins(struct string_list *list, unsigned int exclude_option);
+
+static void exclude_helpers_from_list(struct string_list *list)
+{
+	int i = 0;
+
+	while (i < list->nr) {
+		if (strstr(list->items[i].string, "--"))
+			unsorted_string_list_delete_item(list, i, 0);
+		else
+			i++;
+	}
+}
+
+static int match_token(const char *spec, int len, const char *token)
+{
+	int token_len = strlen(token);
+
+	return len == token_len && !strncmp(spec, token, token_len);
+}
+
+static int list_cmds(const char *spec)
+{
+	struct string_list list = STRING_LIST_INIT_DUP;
+	int i;
+	int nongit;
+
+	/*
+	* Set up the repository so we can pick up any repo-level config (like
+	* completion.commands).
+	*/
+	setup_git_directory_gently(&nongit);
+
+	while (*spec) {
+		const char *sep = strchrnul(spec, ',');
+		int len = sep - spec;
+
+		if (match_token(spec, len, "builtins"))
+			list_builtins(&list, 0);
+		else if (match_token(spec, len, "main"))
+			list_all_main_cmds(&list);
+		else if (match_token(spec, len, "others"))
+			list_all_other_cmds(&list);
+		else if (match_token(spec, len, "nohelpers"))
+			exclude_helpers_from_list(&list);
+		else if (match_token(spec, len, "alias"))
+			list_aliases(&list);
+		else if (match_token(spec, len, "config"))
+			list_cmds_by_config(&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;
+		if (*spec == ',')
+			spec++;
+	}
+	for (i = 0; i < list.nr; i++)
+		puts(list.items[i].string);
+	string_list_clear(&list, 0);
+	return 0;
+}
+
+static void commit_pager_choice(void)
+{
+	switch (use_pager) {
+	case 0:
+		setenv("GIT_PAGER", "cat", 1);
+		break;
+	case 1:
+		setup_pager();
+		break;
+	default:
+		break;
+	}
+}
+
+void setup_auto_pager(const char *cmd, int def)
+{
+	if (use_pager != -1 || pager_in_use())
+		return;
+	use_pager = check_pager_config(cmd);
+	if (use_pager == -1)
+		use_pager = def;
+	commit_pager_choice();
+}
+
+static int handle_options(const char ***argv, int *argc, int *envchanged)
+{
+	const char **orig_argv = *argv;
+
+	while (*argc > 0) {
+		const char *cmd = (*argv)[0];
+		if (cmd[0] != '-')
+			break;
+
+		/*
+		 * For legacy reasons, the "version" and "help"
+		 * commands can be written with "--" prepended
+		 * to make them look like flags.
+		 */
+		if (!strcmp(cmd, "--help") || !strcmp(cmd, "--version"))
+			break;
+
+		/*
+		 * Check remaining flags.
+		 */
+		if (skip_prefix(cmd, "--exec-path", &cmd)) {
+			if (*cmd == '=')
+				git_set_exec_path(cmd + 1);
+			else {
+				puts(git_exec_path());
+				trace2_cmd_name("_query_");
+				exit(0);
+			}
+		} else if (!strcmp(cmd, "--html-path")) {
+			puts(system_path(GIT_HTML_PATH));
+			trace2_cmd_name("_query_");
+			exit(0);
+		} else if (!strcmp(cmd, "--man-path")) {
+			puts(system_path(GIT_MAN_PATH));
+			trace2_cmd_name("_query_");
+			exit(0);
+		} else if (!strcmp(cmd, "--info-path")) {
+			puts(system_path(GIT_INFO_PATH));
+			trace2_cmd_name("_query_");
+			exit(0);
+		} else if (!strcmp(cmd, "-p") || !strcmp(cmd, "--paginate")) {
+			use_pager = 1;
+		} else if (!strcmp(cmd, "-P") || !strcmp(cmd, "--no-pager")) {
+			use_pager = 0;
+			if (envchanged)
+				*envchanged = 1;
+		} else if (!strcmp(cmd, "--no-replace-objects")) {
+			read_replace_refs = 0;
+			setenv(NO_REPLACE_OBJECTS_ENVIRONMENT, "1", 1);
+			if (envchanged)
+				*envchanged = 1;
+		} else if (!strcmp(cmd, "--git-dir")) {
+			if (*argc < 2) {
+				fprintf(stderr, _("no directory given for --git-dir\n" ));
+				usage(git_usage_string);
+			}
+			setenv(GIT_DIR_ENVIRONMENT, (*argv)[1], 1);
+			if (envchanged)
+				*envchanged = 1;
+			(*argv)++;
+			(*argc)--;
+		} else if (skip_prefix(cmd, "--git-dir=", &cmd)) {
+			setenv(GIT_DIR_ENVIRONMENT, cmd, 1);
+			if (envchanged)
+				*envchanged = 1;
+		} else if (!strcmp(cmd, "--namespace")) {
+			if (*argc < 2) {
+				fprintf(stderr, _("no namespace given for --namespace\n" ));
+				usage(git_usage_string);
+			}
+			setenv(GIT_NAMESPACE_ENVIRONMENT, (*argv)[1], 1);
+			if (envchanged)
+				*envchanged = 1;
+			(*argv)++;
+			(*argc)--;
+		} else if (skip_prefix(cmd, "--namespace=", &cmd)) {
+			setenv(GIT_NAMESPACE_ENVIRONMENT, cmd, 1);
+			if (envchanged)
+				*envchanged = 1;
+		} else if (!strcmp(cmd, "--work-tree")) {
+			if (*argc < 2) {
+				fprintf(stderr, _("no directory given for --work-tree\n" ));
+				usage(git_usage_string);
+			}
+			setenv(GIT_WORK_TREE_ENVIRONMENT, (*argv)[1], 1);
+			if (envchanged)
+				*envchanged = 1;
+			(*argv)++;
+			(*argc)--;
+		} else if (skip_prefix(cmd, "--work-tree=", &cmd)) {
+			setenv(GIT_WORK_TREE_ENVIRONMENT, cmd, 1);
+			if (envchanged)
+				*envchanged = 1;
+		} else if (!strcmp(cmd, "--super-prefix")) {
+			if (*argc < 2) {
+				fprintf(stderr, _("no prefix given for --super-prefix\n" ));
+				usage(git_usage_string);
+			}
+			setenv(GIT_SUPER_PREFIX_ENVIRONMENT, (*argv)[1], 1);
+			if (envchanged)
+				*envchanged = 1;
+			(*argv)++;
+			(*argc)--;
+		} else if (skip_prefix(cmd, "--super-prefix=", &cmd)) {
+			setenv(GIT_SUPER_PREFIX_ENVIRONMENT, cmd, 1);
+			if (envchanged)
+				*envchanged = 1;
+		} else if (!strcmp(cmd, "--bare")) {
+			char *cwd = xgetcwd();
+			is_bare_repository_cfg = 1;
+			setenv(GIT_DIR_ENVIRONMENT, cwd, 0);
+			free(cwd);
+			setenv(GIT_IMPLICIT_WORK_TREE_ENVIRONMENT, "0", 1);
+			if (envchanged)
+				*envchanged = 1;
+		} else if (!strcmp(cmd, "-c")) {
+			if (*argc < 2) {
+				fprintf(stderr, _("-c expects a configuration string\n" ));
+				usage(git_usage_string);
+			}
+			git_config_push_parameter((*argv)[1]);
+			(*argv)++;
+			(*argc)--;
+		} else if (!strcmp(cmd, "--literal-pathspecs")) {
+			setenv(GIT_LITERAL_PATHSPECS_ENVIRONMENT, "1", 1);
+			if (envchanged)
+				*envchanged = 1;
+		} else if (!strcmp(cmd, "--no-literal-pathspecs")) {
+			setenv(GIT_LITERAL_PATHSPECS_ENVIRONMENT, "0", 1);
+			if (envchanged)
+				*envchanged = 1;
+		} else if (!strcmp(cmd, "--glob-pathspecs")) {
+			setenv(GIT_GLOB_PATHSPECS_ENVIRONMENT, "1", 1);
+			if (envchanged)
+				*envchanged = 1;
+		} else if (!strcmp(cmd, "--noglob-pathspecs")) {
+			setenv(GIT_NOGLOB_PATHSPECS_ENVIRONMENT, "1", 1);
+			if (envchanged)
+				*envchanged = 1;
+		} else if (!strcmp(cmd, "--icase-pathspecs")) {
+			setenv(GIT_ICASE_PATHSPECS_ENVIRONMENT, "1", 1);
+			if (envchanged)
+				*envchanged = 1;
+		} else if (!strcmp(cmd, "--no-optional-locks")) {
+			setenv(GIT_OPTIONAL_LOCKS_ENVIRONMENT, "0", 1);
+			if (envchanged)
+				*envchanged = 1;
+		} else if (!strcmp(cmd, "--shallow-file")) {
+			(*argv)++;
+			(*argc)--;
+			set_alternate_shallow_file(the_repository, (*argv)[0], 1);
+			if (envchanged)
+				*envchanged = 1;
+		} else if (!strcmp(cmd, "-C")) {
+			if (*argc < 2) {
+				fprintf(stderr, _("no directory given for -C\n" ));
+				usage(git_usage_string);
+			}
+			if ((*argv)[1][0]) {
+				if (chdir((*argv)[1]))
+					die_errno("cannot change to '%s'", (*argv)[1]);
+				if (envchanged)
+					*envchanged = 1;
+			}
+			(*argv)++;
+			(*argc)--;
+		} else if (skip_prefix(cmd, "--list-cmds=", &cmd)) {
+			trace2_cmd_name("_query_");
+			if (!strcmp(cmd, "parseopt")) {
+				struct string_list list = STRING_LIST_INIT_DUP;
+				int i;
+
+				list_builtins(&list, NO_PARSEOPT);
+				for (i = 0; i < list.nr; i++)
+					printf("%s ", list.items[i].string);
+				string_list_clear(&list, 0);
+				exit(0);
+			} else {
+				exit(list_cmds(cmd));
+			}
+		} else {
+			fprintf(stderr, _("unknown option: %s\n"), cmd);
+			usage(git_usage_string);
+		}
+
+		(*argv)++;
+		(*argc)--;
+	}
+	return (*argv) - orig_argv;
+}
+
+static int handle_alias(int *argcp, const char ***argv)
+{
+	int envchanged = 0, ret = 0, saved_errno = errno;
+	int count, option_count;
+	const char **new_argv;
+	const char *alias_command;
+	char *alias_string;
+
+	alias_command = (*argv)[0];
+	alias_string = alias_lookup(alias_command);
+	if (alias_string) {
+		if (*argcp > 1 && !strcmp((*argv)[1], "-h"))
+			fprintf_ln(stderr, _("'%s' is aliased to '%s'"),
+				   alias_command, alias_string);
+		if (alias_string[0] == '!') {
+			struct child_process child = CHILD_PROCESS_INIT;
+			int nongit_ok;
+
+			/* Aliases expect GIT_PREFIX, GIT_DIR etc to be set */
+			setup_git_directory_gently(&nongit_ok);
+
+			commit_pager_choice();
+
+			child.use_shell = 1;
+			child.trace2_child_class = "shell_alias";
+			argv_array_push(&child.args, alias_string + 1);
+			argv_array_pushv(&child.args, (*argv) + 1);
+
+			trace2_cmd_alias(alias_command, child.args.argv);
+			trace2_cmd_list_config();
+			trace2_cmd_name("_run_shell_alias_");
+
+			ret = run_command(&child);
+			if (ret >= 0)   /* normal exit */
+				exit(ret);
+
+			die_errno(_("while expanding alias '%s': '%s'"),
+				  alias_command, alias_string + 1);
+		}
+		count = split_cmdline(alias_string, &new_argv);
+		if (count < 0)
+			die(_("bad alias.%s string: %s"), alias_command,
+			    _(split_cmdline_strerror(count)));
+		option_count = handle_options(&new_argv, &count, &envchanged);
+		if (envchanged)
+			die(_("alias '%s' changes environment variables.\n"
+			      "You can use '!git' in the alias to do this"),
+			    alias_command);
+		memmove(new_argv - option_count, new_argv,
+				count * sizeof(char *));
+		new_argv -= option_count;
+
+		if (count < 1)
+			die(_("empty alias for %s"), alias_command);
+
+		if (!strcmp(alias_command, new_argv[0]))
+			die(_("recursive alias: %s"), alias_command);
+
+		trace_argv_printf(new_argv,
+				  "trace: alias expansion: %s =>",
+				  alias_command);
+
+		REALLOC_ARRAY(new_argv, count + *argcp);
+		/* insert after command name */
+		memcpy(new_argv + count, *argv + 1, sizeof(char *) * *argcp);
+
+		trace2_cmd_alias(alias_command, new_argv);
+		trace2_cmd_list_config();
+
+		*argv = new_argv;
+		*argcp += count - 1;
+
+		ret = 1;
+	}
+
+	errno = saved_errno;
+
+	return ret;
+}
+
+static int run_builtin(struct cmd_struct *p, int argc, const char **argv)
+{
+	int status, help;
+	struct stat st;
+	const char *prefix;
+
+	prefix = NULL;
+	help = argc == 2 && !strcmp(argv[1], "-h");
+	if (!help) {
+		if (p->option & RUN_SETUP)
+			prefix = setup_git_directory();
+		else if (p->option & RUN_SETUP_GENTLY) {
+			int nongit_ok;
+			prefix = setup_git_directory_gently(&nongit_ok);
+		}
+
+		if (use_pager == -1 && p->option & (RUN_SETUP | RUN_SETUP_GENTLY) &&
+		    !(p->option & DELAY_PAGER_CONFIG))
+			use_pager = check_pager_config(p->cmd);
+		if (use_pager == -1 && p->option & USE_PAGER)
+			use_pager = 1;
+
+		if ((p->option & (RUN_SETUP | RUN_SETUP_GENTLY)) &&
+		    startup_info->have_repository) /* get_git_dir() may set up repo, avoid that */
+			trace_repo_setup(prefix);
+	}
+	commit_pager_choice();
+
+	if (!help && get_super_prefix()) {
+		if (!(p->option & SUPPORT_SUPER_PREFIX))
+			die(_("%s doesn't support --super-prefix"), p->cmd);
+	}
+
+	if (!help && p->option & NEED_WORK_TREE)
+		setup_work_tree();
+
+	trace_argv_printf(argv, "trace: built-in: git");
+	trace2_cmd_name(p->cmd);
+	trace2_cmd_list_config();
+
+	validate_cache_entries(the_repository->index);
+	status = p->fn(argc, argv, prefix);
+	validate_cache_entries(the_repository->index);
+
+	if (status)
+		return status;
+
+	/* Somebody closed stdout? */
+	if (fstat(fileno(stdout), &st))
+		return 0;
+	/* Ignore write errors for pipes and sockets.. */
+	if (S_ISFIFO(st.st_mode) || S_ISSOCK(st.st_mode))
+		return 0;
+
+	/* Check for ENOSPC and EIO errors.. */
+	if (fflush(stdout))
+		die_errno(_("write failure on standard output"));
+	if (ferror(stdout))
+		die(_("unknown write failure on standard output"));
+	if (fclose(stdout))
+		die_errno(_("close failed on standard output"));
+	return 0;
+}
+
+static struct cmd_struct commands[] = {
+	{ "add", cmd_add, RUN_SETUP | NEED_WORK_TREE },
+	{ "am", cmd_am, RUN_SETUP | NEED_WORK_TREE },
+	{ "annotate", cmd_annotate, RUN_SETUP | NO_PARSEOPT },
+	{ "apply", cmd_apply, RUN_SETUP_GENTLY },
+	{ "archive", cmd_archive, RUN_SETUP_GENTLY },
+	{ "bisect--helper", cmd_bisect__helper, RUN_SETUP },
+	{ "blame", cmd_blame, RUN_SETUP },
+	{ "branch", cmd_branch, RUN_SETUP | DELAY_PAGER_CONFIG },
+	{ "bundle", cmd_bundle, RUN_SETUP_GENTLY | NO_PARSEOPT },
+	{ "cat-file", cmd_cat_file, RUN_SETUP },
+	{ "check-attr", cmd_check_attr, RUN_SETUP },
+	{ "check-ignore", cmd_check_ignore, RUN_SETUP | NEED_WORK_TREE },
+	{ "check-mailmap", cmd_check_mailmap, RUN_SETUP },
+	{ "check-ref-format", cmd_check_ref_format, NO_PARSEOPT  },
+	{ "checkout", cmd_checkout, RUN_SETUP | NEED_WORK_TREE },
+	{ "checkout-index", cmd_checkout_index,
+		RUN_SETUP | NEED_WORK_TREE},
+	{ "cherry", cmd_cherry, RUN_SETUP },
+	{ "cherry-pick", cmd_cherry_pick, RUN_SETUP | NEED_WORK_TREE },
+	{ "clean", cmd_clean, RUN_SETUP | NEED_WORK_TREE },
+	{ "clone", cmd_clone },
+	{ "column", cmd_column, RUN_SETUP_GENTLY },
+	{ "commit", cmd_commit, RUN_SETUP | NEED_WORK_TREE },
+	{ "commit-graph", cmd_commit_graph, RUN_SETUP },
+	{ "commit-tree", cmd_commit_tree, RUN_SETUP | NO_PARSEOPT },
+	{ "config", cmd_config, RUN_SETUP_GENTLY | DELAY_PAGER_CONFIG },
+	{ "count-objects", cmd_count_objects, RUN_SETUP },
+	{ "credential", cmd_credential, RUN_SETUP_GENTLY | NO_PARSEOPT },
+	{ "describe", cmd_describe, RUN_SETUP },
+	{ "diff", cmd_diff, NO_PARSEOPT },
+	{ "diff-files", cmd_diff_files, RUN_SETUP | NEED_WORK_TREE | NO_PARSEOPT },
+	{ "diff-index", cmd_diff_index, RUN_SETUP | NO_PARSEOPT },
+	{ "diff-tree", cmd_diff_tree, RUN_SETUP | NO_PARSEOPT },
+	{ "difftool", cmd_difftool, RUN_SETUP_GENTLY },
+	{ "env--helper", cmd_env__helper },
+	{ "fast-export", cmd_fast_export, RUN_SETUP },
+	{ "fetch", cmd_fetch, RUN_SETUP },
+	{ "fetch-pack", cmd_fetch_pack, RUN_SETUP | NO_PARSEOPT },
+	{ "fmt-merge-msg", cmd_fmt_merge_msg, RUN_SETUP },
+	{ "for-each-ref", cmd_for_each_ref, RUN_SETUP },
+	{ "format-patch", cmd_format_patch, RUN_SETUP },
+	{ "fsck", cmd_fsck, RUN_SETUP },
+	{ "fsck-objects", cmd_fsck, RUN_SETUP },
+	{ "gc", cmd_gc, RUN_SETUP },
+	{ "get-tar-commit-id", cmd_get_tar_commit_id, NO_PARSEOPT },
+	{ "grep", cmd_grep, RUN_SETUP_GENTLY },
+	{ "hash-object", cmd_hash_object },
+	{ "help", cmd_help },
+	{ "index-pack", cmd_index_pack, RUN_SETUP_GENTLY | NO_PARSEOPT },
+	{ "init", cmd_init_db },
+	{ "init-db", cmd_init_db },
+	{ "interpret-trailers", cmd_interpret_trailers, RUN_SETUP_GENTLY },
+	{ "log", cmd_log, RUN_SETUP },
+	{ "ls-files", cmd_ls_files, RUN_SETUP },
+	{ "ls-remote", cmd_ls_remote, RUN_SETUP_GENTLY },
+	{ "ls-tree", cmd_ls_tree, RUN_SETUP },
+	{ "mailinfo", cmd_mailinfo, RUN_SETUP_GENTLY | NO_PARSEOPT },
+	{ "mailsplit", cmd_mailsplit, NO_PARSEOPT },
+	{ "merge", cmd_merge, RUN_SETUP | NEED_WORK_TREE },
+	{ "merge-base", cmd_merge_base, RUN_SETUP },
+	{ "merge-file", cmd_merge_file, RUN_SETUP_GENTLY },
+	{ "merge-index", cmd_merge_index, RUN_SETUP | NO_PARSEOPT },
+	{ "merge-ours", cmd_merge_ours, RUN_SETUP | NO_PARSEOPT },
+	{ "merge-recursive", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE | NO_PARSEOPT },
+	{ "merge-recursive-ours", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE | NO_PARSEOPT },
+	{ "merge-recursive-theirs", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE | NO_PARSEOPT },
+	{ "merge-subtree", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE | NO_PARSEOPT },
+	{ "merge-tree", cmd_merge_tree, RUN_SETUP | NO_PARSEOPT },
+	{ "mktag", cmd_mktag, RUN_SETUP | NO_PARSEOPT },
+	{ "mktree", cmd_mktree, RUN_SETUP },
+	{ "multi-pack-index", cmd_multi_pack_index, RUN_SETUP_GENTLY },
+	{ "mv", cmd_mv, RUN_SETUP | NEED_WORK_TREE },
+	{ "name-rev", cmd_name_rev, RUN_SETUP },
+	{ "notes", cmd_notes, RUN_SETUP },
+	{ "pack-objects", cmd_pack_objects, RUN_SETUP },
+	{ "pack-redundant", cmd_pack_redundant, RUN_SETUP | NO_PARSEOPT },
+	{ "pack-refs", cmd_pack_refs, RUN_SETUP },
+	{ "patch-id", cmd_patch_id, RUN_SETUP_GENTLY | NO_PARSEOPT },
+	{ "pickaxe", cmd_blame, RUN_SETUP },
+	{ "prune", cmd_prune, RUN_SETUP },
+	{ "prune-packed", cmd_prune_packed, RUN_SETUP },
+	{ "pull", cmd_pull, RUN_SETUP | NEED_WORK_TREE },
+	{ "push", cmd_push, RUN_SETUP },
+	{ "range-diff", cmd_range_diff, RUN_SETUP | USE_PAGER },
+	{ "read-tree", cmd_read_tree, RUN_SETUP | SUPPORT_SUPER_PREFIX},
+	{ "rebase", cmd_rebase, RUN_SETUP | NEED_WORK_TREE },
+	{ "rebase--interactive", cmd_rebase__interactive, RUN_SETUP | NEED_WORK_TREE },
+	{ "receive-pack", cmd_receive_pack },
+	{ "reflog", cmd_reflog, RUN_SETUP },
+	{ "remote", cmd_remote, RUN_SETUP },
+	{ "remote-ext", cmd_remote_ext, NO_PARSEOPT },
+	{ "remote-fd", cmd_remote_fd, NO_PARSEOPT },
+	{ "repack", cmd_repack, RUN_SETUP },
+	{ "replace", cmd_replace, RUN_SETUP },
+	{ "rerere", cmd_rerere, RUN_SETUP },
+	{ "reset", cmd_reset, RUN_SETUP },
+	{ "restore", cmd_restore, RUN_SETUP | NEED_WORK_TREE },
+	{ "rev-list", cmd_rev_list, RUN_SETUP | NO_PARSEOPT },
+	{ "rev-parse", cmd_rev_parse, NO_PARSEOPT },
+	{ "revert", cmd_revert, RUN_SETUP | NEED_WORK_TREE },
+	{ "rm", cmd_rm, RUN_SETUP },
+	{ "send-pack", cmd_send_pack, RUN_SETUP },
+	{ "shortlog", cmd_shortlog, RUN_SETUP_GENTLY | USE_PAGER },
+	{ "show", cmd_show, RUN_SETUP },
+	{ "show-branch", cmd_show_branch, RUN_SETUP },
+	{ "show-index", cmd_show_index },
+	{ "show-ref", cmd_show_ref, RUN_SETUP },
+	{ "stage", cmd_add, RUN_SETUP | NEED_WORK_TREE },
+	/*
+	 * NEEDSWORK: Until the builtin stash is thoroughly robust and no
+	 * longer needs redirection to the stash shell script this is kept as
+	 * is, then should be changed to RUN_SETUP | NEED_WORK_TREE
+	 */
+	{ "stash", cmd_stash },
+	{ "status", cmd_status, RUN_SETUP | NEED_WORK_TREE },
+	{ "stripspace", cmd_stripspace },
+	{ "submodule--helper", cmd_submodule__helper, RUN_SETUP | SUPPORT_SUPER_PREFIX | NO_PARSEOPT },
+	{ "switch", cmd_switch, RUN_SETUP | NEED_WORK_TREE },
+	{ "symbolic-ref", cmd_symbolic_ref, RUN_SETUP },
+	{ "tag", cmd_tag, RUN_SETUP | DELAY_PAGER_CONFIG },
+	{ "unpack-file", cmd_unpack_file, RUN_SETUP | NO_PARSEOPT },
+	{ "unpack-objects", cmd_unpack_objects, RUN_SETUP | NO_PARSEOPT },
+	{ "update-index", cmd_update_index, RUN_SETUP },
+	{ "update-ref", cmd_update_ref, RUN_SETUP },
+	{ "update-server-info", cmd_update_server_info, RUN_SETUP },
+	{ "upload-archive", cmd_upload_archive, NO_PARSEOPT },
+	{ "upload-archive--writer", cmd_upload_archive_writer, NO_PARSEOPT },
+	{ "upload-pack", cmd_upload_pack },
+	{ "var", cmd_var, RUN_SETUP_GENTLY | NO_PARSEOPT },
+	{ "verify-commit", cmd_verify_commit, RUN_SETUP },
+	{ "verify-pack", cmd_verify_pack },
+	{ "verify-tag", cmd_verify_tag, RUN_SETUP },
+	{ "version", cmd_version },
+	{ "whatchanged", cmd_whatchanged, RUN_SETUP },
+	{ "worktree", cmd_worktree, RUN_SETUP | NO_PARSEOPT },
+	{ "write-tree", cmd_write_tree, RUN_SETUP },
+};
+
+static struct cmd_struct *get_builtin(const char *s)
+{
+	int i;
+	for (i = 0; i < ARRAY_SIZE(commands); i++) {
+		struct cmd_struct *p = commands + i;
+		if (!strcmp(s, p->cmd))
+			return p;
+	}
+	return NULL;
+}
+
+int is_builtin(const char *s)
+{
+	return !!get_builtin(s);
+}
+
+static void list_builtins(struct string_list *out, unsigned int exclude_option)
+{
+	int i;
+	for (i = 0; i < ARRAY_SIZE(commands); i++) {
+		if (exclude_option &&
+		    (commands[i].option & exclude_option))
+			continue;
+		string_list_append(out, commands[i].cmd);
+	}
+}
+
+#ifdef STRIP_EXTENSION
+static void strip_extension(const char **argv)
+{
+	size_t len;
+
+	if (strip_suffix(argv[0], STRIP_EXTENSION, &len))
+		argv[0] = xmemdupz(argv[0], len);
+}
+#else
+#define strip_extension(cmd)
+#endif
+
+static void handle_builtin(int argc, const char **argv)
+{
+	struct argv_array args = ARGV_ARRAY_INIT;
+	const char *cmd;
+	struct cmd_struct *builtin;
+
+	strip_extension(argv);
+	cmd = argv[0];
+
+	/* Turn "git cmd --help" into "git help --exclude-guides cmd" */
+	if (argc > 1 && !strcmp(argv[1], "--help")) {
+		int i;
+
+		argv[1] = argv[0];
+		argv[0] = cmd = "help";
+
+		for (i = 0; i < argc; i++) {
+			argv_array_push(&args, argv[i]);
+			if (!i)
+				argv_array_push(&args, "--exclude-guides");
+		}
+
+		argc++;
+		argv = args.argv;
+	}
+
+	builtin = get_builtin(cmd);
+	if (builtin)
+		exit(run_builtin(builtin, argc, argv));
+	argv_array_clear(&args);
+}
+
+static void execv_dashed_external(const char **argv)
+{
+	struct child_process cmd = CHILD_PROCESS_INIT;
+	int status;
+
+	if (get_super_prefix())
+		die(_("%s doesn't support --super-prefix"), argv[0]);
+
+	if (use_pager == -1 && !is_builtin(argv[0]))
+		use_pager = check_pager_config(argv[0]);
+	commit_pager_choice();
+
+	argv_array_pushf(&cmd.args, "git-%s", argv[0]);
+	argv_array_pushv(&cmd.args, argv + 1);
+	cmd.clean_on_exit = 1;
+	cmd.wait_after_clean = 1;
+	cmd.silent_exec_failure = 1;
+	cmd.trace2_child_class = "dashed";
+
+	trace2_cmd_name("_run_dashed_");
+
+	/*
+	 * The code in run_command() logs trace2 child_start/child_exit
+	 * events, so we do not need to report exec/exec_result events here.
+	 */
+	trace_argv_printf(cmd.args.argv, "trace: exec:");
+
+	/*
+	 * If we fail because the command is not found, it is
+	 * OK to return. Otherwise, we just pass along the status code,
+	 * or our usual generic code if we were not even able to exec
+	 * the program.
+	 */
+	status = run_command(&cmd);
+
+	/*
+	 * If the child process ran and we are now going to exit, emit a
+	 * generic string as our trace2 command verb to indicate that we
+	 * launched a dashed command.
+	 */
+	if (status >= 0)
+		exit(status);
+	else if (errno != ENOENT)
+		exit(128);
+}
+
+static int run_argv(int *argcp, const char ***argv)
+{
+	int done_alias = 0;
+	struct string_list cmd_list = STRING_LIST_INIT_NODUP;
+	struct string_list_item *seen;
+
+	while (1) {
+		/*
+		 * If we tried alias and futzed with our environment,
+		 * it no longer is safe to invoke builtins directly in
+		 * general.  We have to spawn them as dashed externals.
+		 *
+		 * NEEDSWORK: if we can figure out cases
+		 * where it is safe to do, we can avoid spawning a new
+		 * process.
+		 */
+		if (!done_alias)
+			handle_builtin(*argcp, *argv);
+		else if (get_builtin(**argv)) {
+			struct argv_array args = ARGV_ARRAY_INIT;
+			int i;
+
+			/*
+			 * The current process is committed to launching a
+			 * child process to run the command named in (**argv)
+			 * and exiting.  Log a generic string as the trace2
+			 * command verb to indicate this.  Note that the child
+			 * process will log the actual verb when it runs.
+			 */
+			trace2_cmd_name("_run_git_alias_");
+
+			if (get_super_prefix())
+				die("%s doesn't support --super-prefix", **argv);
+
+			commit_pager_choice();
+
+			argv_array_push(&args, "git");
+			for (i = 0; i < *argcp; i++)
+				argv_array_push(&args, (*argv)[i]);
+
+			trace_argv_printf(args.argv, "trace: exec:");
+
+			/*
+			 * if we fail because the command is not found, it is
+			 * OK to return. Otherwise, we just pass along the status code.
+			 */
+			i = run_command_v_opt_tr2(args.argv, RUN_SILENT_EXEC_FAILURE |
+						  RUN_CLEAN_ON_EXIT, "git_alias");
+			if (i >= 0 || errno != ENOENT)
+				exit(i);
+			die("could not execute builtin %s", **argv);
+		}
+
+		/* .. then try the external ones */
+		execv_dashed_external(*argv);
+
+		seen = unsorted_string_list_lookup(&cmd_list, *argv[0]);
+		if (seen) {
+			int i;
+			struct strbuf sb = STRBUF_INIT;
+			for (i = 0; i < cmd_list.nr; i++) {
+				struct string_list_item *item = &cmd_list.items[i];
+
+				strbuf_addf(&sb, "\n  %s", item->string);
+				if (item == seen)
+					strbuf_addstr(&sb, " <==");
+				else if (i == cmd_list.nr - 1)
+					strbuf_addstr(&sb, " ==>");
+			}
+			die(_("alias loop detected: expansion of '%s' does"
+			      " not terminate:%s"), cmd_list.items[0].string, sb.buf);
+		}
+
+		string_list_append(&cmd_list, *argv[0]);
+
+		/*
+		 * It could be an alias -- this works around the insanity
+		 * of overriding "git log" with "git show" by having
+		 * alias.log = show
+		 */
+		if (!handle_alias(argcp, argv))
+			break;
+		done_alias = 1;
+	}
+
+	string_list_clear(&cmd_list, 0);
+
+	return done_alias;
+}
+
+int cmd_main(int argc, const char **argv)
+{
+	const char *cmd;
+	int done_help = 0;
+
+	cmd = argv[0];
+	if (!cmd)
+		cmd = "git-help";
+	else {
+		const char *slash = find_last_dir_sep(cmd);
+		if (slash)
+			cmd = slash + 1;
+	}
+
+	trace_command_performance(argv);
+
+	/*
+	 * "git-xxxx" is the same as "git xxxx", but we obviously:
+	 *
+	 *  - cannot take flags in between the "git" and the "xxxx".
+	 *  - cannot execute it externally (since it would just do
+	 *    the same thing over again)
+	 *
+	 * So we just directly call the builtin handler, and die if
+	 * that one cannot handle it.
+	 */
+	if (skip_prefix(cmd, "git-", &cmd)) {
+		argv[0] = cmd;
+		handle_builtin(argc, argv);
+		die(_("cannot handle %s as a builtin"), cmd);
+	}
+
+	/* Look for flags.. */
+	argv++;
+	argc--;
+	handle_options(&argv, &argc, NULL);
+	if (argc > 0) {
+		/* translate --help and --version into commands */
+		skip_prefix(argv[0], "--", &argv[0]);
+	} else {
+		/* The user didn't specify a command; give them help */
+		commit_pager_choice();
+		printf(_("usage: %s\n\n"), git_usage_string);
+		list_common_cmds_help();
+		printf("\n%s\n", _(git_more_info_string));
+		exit(1);
+	}
+	cmd = argv[0];
+
+	/*
+	 * We use PATH to find git commands, but we prepend some higher
+	 * precedence paths: the "--exec-path" option, the GIT_EXEC_PATH
+	 * environment, and the $(gitexecdir) from the Makefile at build
+	 * time.
+	 */
+	setup_path();
+
+	while (1) {
+		int was_alias = run_argv(&argc, &argv);
+		if (errno != ENOENT)
+			break;
+		if (was_alias) {
+			fprintf(stderr, _("expansion of alias '%s' failed; "
+					  "'%s' is not a git command\n"),
+				cmd, argv[0]);
+			exit(1);
+		}
+		if (!done_help) {
+			cmd = argv[0] = help_unknown_cmd(cmd);
+			done_help = 1;
+		} else
+			break;
+	}
+
+	fprintf(stderr, _("failed to run command '%s': %s\n"),
+		cmd, strerror(errno));
+
+	return 1;
+}