merge(3p/git): Merge git subtree at v2.29.2 r/1890

This also bumps the stable nixpkgs to 20.09 as of 2020-11-21, because
there is some breakage in the git build related to the netrc
credentials helper which someone has taken care of in nixpkgs.

The stable channel is not used for anything other than git, so this
should be fine.

Change-Id: I3575a19dab09e1e9556cf8231d717de9890484fb

1 files changed, 369 insertions, 102 deletions

diff --git a/third_party/git/builtin/bisect--helper.c b/third_party/git/builtin/bisect--helper.c
index 1fbe156e67a4..7512b880f0d6 100644
--- a/third_party/git/builtin/bisect--helper.c
+++ b/third_party/git/builtin/bisect--helper.c
@@ -4,22 +4,23 @@
 #include "bisect.h"
 #include "refs.h"
 #include "dir.h"
-#include "argv-array.h"
+#include "strvec.h"
 #include "run-command.h"
 #include "prompt.h"
 #include "quote.h"
+#include "revision.h"
 
 static GIT_PATH_FUNC(git_path_bisect_terms, "BISECT_TERMS")
 static GIT_PATH_FUNC(git_path_bisect_expected_rev, "BISECT_EXPECTED_REV")
 static GIT_PATH_FUNC(git_path_bisect_ancestors_ok, "BISECT_ANCESTORS_OK")
 static GIT_PATH_FUNC(git_path_bisect_start, "BISECT_START")
-static GIT_PATH_FUNC(git_path_bisect_head, "BISECT_HEAD")
 static GIT_PATH_FUNC(git_path_bisect_log, "BISECT_LOG")
 static GIT_PATH_FUNC(git_path_head_name, "head-name")
 static GIT_PATH_FUNC(git_path_bisect_names, "BISECT_NAMES")
+static GIT_PATH_FUNC(git_path_bisect_first_parent, "BISECT_FIRST_PARENT")
 
 static const char * const git_bisect_helper_usage[] = {
-	N_("git bisect--helper --next-all [--no-checkout]"),
+	N_("git bisect--helper --next-all"),
 	N_("git bisect--helper --write-terms <bad_term> <good_term>"),
 	N_("git bisect--helper --bisect-clean-state"),
 	N_("git bisect--helper --bisect-reset [<commit>]"),
@@ -27,11 +28,19 @@ static const char * const git_bisect_helper_usage[] = {
 	N_("git bisect--helper --bisect-check-and-set-terms <command> <good_term> <bad_term>"),
 	N_("git bisect--helper --bisect-next-check <good_term> <bad_term> [<term>]"),
 	N_("git bisect--helper --bisect-terms [--term-good | --term-old | --term-bad | --term-new]"),
-	N_("git bisect--helper --bisect-start [--term-{old,good}=<term> --term-{new,bad}=<term>]"
-					     "[--no-checkout] [<bad> [<good>...]] [--] [<paths>...]"),
+	N_("git bisect--helper --bisect-start [--term-{new,bad}=<term> --term-{old,good}=<term>]"
+					    " [--no-checkout] [--first-parent] [<bad> [<good>...]] [--] [<paths>...]"),
+	N_("git bisect--helper --bisect-next"),
+	N_("git bisect--helper --bisect-auto-next"),
+	N_("git bisect--helper --bisect-autostart"),
 	NULL
 };
 
+struct add_bisect_ref_data {
+	struct rev_info *revs;
+	unsigned int object_flags;
+};
+
 struct bisect_terms {
 	char *term_good;
 	char *term_bad;
@@ -52,8 +61,10 @@ static void set_terms(struct bisect_terms *terms, const char *bad,
 	terms->term_bad = xstrdup(bad);
 }
 
-static const char *vocab_bad = "bad|new";
-static const char *vocab_good = "good|old";
+static const char vocab_bad[] = "bad|new";
+static const char vocab_good[] = "good|old";
+
+static int bisect_autostart(struct bisect_terms *terms);
 
 /*
  * Check whether the string `term` belongs to the set of strings
@@ -74,6 +85,52 @@ static int one_of(const char *term, ...)
 	return res;
 }
 
+static int write_in_file(const char *path, const char *mode, const char *format, va_list args)
+{
+	FILE *fp = NULL;
+	int res = 0;
+
+	if (strcmp(mode, "w") && strcmp(mode, "a"))
+		BUG("write-in-file does not support '%s' mode", mode);
+	fp = fopen(path, mode);
+	if (!fp)
+		return error_errno(_("cannot open file '%s' in mode '%s'"), path, mode);
+	res = vfprintf(fp, format, args);
+
+	if (res < 0) {
+		int saved_errno = errno;
+		fclose(fp);
+		errno = saved_errno;
+		return error_errno(_("could not write to file '%s'"), path);
+	}
+
+	return fclose(fp);
+}
+
+static int write_to_file(const char *path, const char *format, ...)
+{
+	int res;
+	va_list args;
+
+	va_start(args, format);
+	res = write_in_file(path, "w", format, args);
+	va_end(args);
+
+	return res;
+}
+
+static int append_to_file(const char *path, const char *format, ...)
+{
+	int res;
+	va_list args;
+
+	va_start(args, format);
+	res = write_in_file(path, "a", format, args);
+	va_end(args);
+
+	return res;
+}
+
 static int check_term_format(const char *term, const char *orig_term)
 {
 	int res;
@@ -104,7 +161,6 @@ static int check_term_format(const char *term, const char *orig_term)
 
 static int write_terms(const char *bad, const char *good)
 {
-	FILE *fp = NULL;
 	int res;
 
 	if (!strcmp(bad, good))
@@ -113,13 +169,9 @@ static int write_terms(const char *bad, const char *good)
 	if (check_term_format(bad, "bad") || check_term_format(good, "good"))
 		return -1;
 
-	fp = fopen(git_path_bisect_terms(), "w");
-	if (!fp)
-		return error_errno(_("could not open the file BISECT_TERMS"));
+	res = write_to_file(git_path_bisect_terms(), "%s\n%s\n", bad, good);
 
-	res = fprintf(fp, "%s\n%s\n", bad, good);
-	res |= fclose(fp);
-	return (res < 0) ? -1 : 0;
+	return res;
 }
 
 static int is_expected_rev(const char *expected_hex)
@@ -164,18 +216,19 @@ static int bisect_reset(const char *commit)
 		strbuf_addstr(&branch, commit);
 	}
 
-	if (!file_exists(git_path_bisect_head())) {
-		struct argv_array argv = ARGV_ARRAY_INIT;
+	if (!ref_exists("BISECT_HEAD")) {
+		struct strvec argv = STRVEC_INIT;
 
-		argv_array_pushl(&argv, "checkout", branch.buf, "--", NULL);
-		if (run_command_v_opt(argv.argv, RUN_GIT_CMD)) {
+		strvec_pushl(&argv, "checkout", branch.buf, "--", NULL);
+		if (run_command_v_opt(argv.v, RUN_GIT_CMD)) {
+			error(_("could not check out original"
+				" HEAD '%s'. Try 'git bisect"
+				" reset <commit>'."), branch.buf);
 			strbuf_release(&branch);
-			argv_array_clear(&argv);
-			return error(_("could not check out original"
-				       " HEAD '%s'. Try 'git bisect"
-				       " reset <commit>'."), branch.buf);
+			strvec_clear(&argv);
+			return -1;
 		}
-		argv_array_clear(&argv);
+		strvec_clear(&argv);
 	}
 
 	strbuf_release(&branch);
@@ -205,31 +258,31 @@ static int bisect_write(const char *state, const char *rev,
 	struct object_id oid;
 	struct commit *commit;
 	FILE *fp = NULL;
-	int retval = 0;
+	int res = 0;
 
 	if (!strcmp(state, terms->term_bad)) {
 		strbuf_addf(&tag, "refs/bisect/%s", state);
 	} else if (one_of(state, terms->term_good, "skip", NULL)) {
 		strbuf_addf(&tag, "refs/bisect/%s-%s", state, rev);
 	} else {
-		retval = error(_("Bad bisect_write argument: %s"), state);
+		res = error(_("Bad bisect_write argument: %s"), state);
 		goto finish;
 	}
 
 	if (get_oid(rev, &oid)) {
-		retval = error(_("couldn't get the oid of the rev '%s'"), rev);
+		res = error(_("couldn't get the oid of the rev '%s'"), rev);
 		goto finish;
 	}
 
 	if (update_ref(NULL, tag.buf, &oid, NULL, 0,
 		       UPDATE_REFS_MSG_ON_ERR)) {
-		retval = -1;
+		res = -1;
 		goto finish;
 	}
 
 	fp = fopen(git_path_bisect_log(), "a");
 	if (!fp) {
-		retval = error_errno(_("couldn't open the file '%s'"), git_path_bisect_log());
+		res = error_errno(_("couldn't open the file '%s'"), git_path_bisect_log());
 		goto finish;
 	}
 
@@ -243,7 +296,7 @@ finish:
 	if (fp)
 		fclose(fp);
 	strbuf_release(&tag);
-	return retval;
+	return res;
 }
 
 static int check_and_set_terms(struct bisect_terms *terms, const char *cmd)
@@ -281,35 +334,23 @@ static int mark_good(const char *refname, const struct object_id *oid,
 	return 1;
 }
 
-static const char *need_bad_and_good_revision_warning =
+static const char need_bad_and_good_revision_warning[] =
 	N_("You need to give me at least one %s and %s revision.\n"
 	   "You can use \"git bisect %s\" and \"git bisect %s\" for that.");
 
-static const char *need_bisect_start_warning =
+static const char need_bisect_start_warning[] =
 	N_("You need to start by \"git bisect start\".\n"
 	   "You then need to give me at least one %s and %s revision.\n"
 	   "You can use \"git bisect %s\" and \"git bisect %s\" for that.");
 
-static int bisect_next_check(const struct bisect_terms *terms,
-			     const char *current_term)
+static int decide_next(const struct bisect_terms *terms,
+		       const char *current_term, int missing_good,
+		       int missing_bad)
 {
-	int missing_good = 1, missing_bad = 1, retval = 0;
-	const char *bad_ref = xstrfmt("refs/bisect/%s", terms->term_bad);
-	const char *good_glob = xstrfmt("%s-*", terms->term_good);
-
-	if (ref_exists(bad_ref))
-		missing_bad = 0;
-
-	for_each_glob_ref_in(mark_good, good_glob, "refs/bisect/",
-			     (void *) &missing_good);
-
 	if (!missing_good && !missing_bad)
-		goto finish;
-
-	if (!current_term) {
-		retval = -1;
-		goto finish;
-	}
+		return 0;
+	if (!current_term)
+		return -1;
 
 	if (missing_good && !missing_bad &&
 	    !strcmp(current_term, terms->term_good)) {
@@ -320,7 +361,7 @@ static int bisect_next_check(const struct bisect_terms *terms,
 		 */
 		warning(_("bisecting only with a %s commit"), terms->term_bad);
 		if (!isatty(0))
-			goto finish;
+			return 0;
 		/*
 		 * TRANSLATORS: Make sure to include [Y] and [n] in your
 		 * translation. The program will only accept English input
@@ -328,21 +369,35 @@ static int bisect_next_check(const struct bisect_terms *terms,
 		 */
 		yesno = git_prompt(_("Are you sure [Y/n]? "), PROMPT_ECHO);
 		if (starts_with(yesno, "N") || starts_with(yesno, "n"))
-			retval = -1;
-		goto finish;
-	}
-	if (!is_empty_or_missing_file(git_path_bisect_start())) {
-		retval = error(_(need_bad_and_good_revision_warning),
-			       vocab_bad, vocab_good, vocab_bad, vocab_good);
-	} else {
-		retval = error(_(need_bisect_start_warning),
-			       vocab_good, vocab_bad, vocab_good, vocab_bad);
+			return -1;
+		return 0;
 	}
 
-finish:
-	free((void *) good_glob);
-	free((void *) bad_ref);
-	return retval;
+	if (!is_empty_or_missing_file(git_path_bisect_start()))
+		return error(_(need_bad_and_good_revision_warning),
+			     vocab_bad, vocab_good, vocab_bad, vocab_good);
+	else
+		return error(_(need_bisect_start_warning),
+			     vocab_good, vocab_bad, vocab_good, vocab_bad);
+}
+
+static int bisect_next_check(const struct bisect_terms *terms,
+			     const char *current_term)
+{
+	int missing_good = 1, missing_bad = 1;
+	char *bad_ref = xstrfmt("refs/bisect/%s", terms->term_bad);
+	char *good_glob = xstrfmt("%s-*", terms->term_good);
+
+	if (ref_exists(bad_ref))
+		missing_bad = 0;
+
+	for_each_glob_ref_in(mark_good, good_glob, "refs/bisect/",
+			     (void *) &missing_good);
+
+	free(good_glob);
+	free(bad_ref);
+
+	return decide_next(terms, current_term, missing_good, missing_bad);
 }
 
 static int get_terms(struct bisect_terms *terms)
@@ -396,7 +451,7 @@ static int bisect_terms(struct bisect_terms *terms, const char *option)
 
 static int bisect_append_log_quoted(const char **argv)
 {
-	int retval = 0;
+	int res = 0;
 	FILE *fp = fopen(git_path_bisect_log(), "a");
 	struct strbuf orig_args = STRBUF_INIT;
 
@@ -404,25 +459,162 @@ static int bisect_append_log_quoted(const char **argv)
 		return -1;
 
 	if (fprintf(fp, "git bisect start") < 1) {
-		retval = -1;
+		res = -1;
 		goto finish;
 	}
 
 	sq_quote_argv(&orig_args, argv);
 	if (fprintf(fp, "%s\n", orig_args.buf) < 1)
-		retval = -1;
+		res = -1;
 
 finish:
 	fclose(fp);
 	strbuf_release(&orig_args);
-	return retval;
+	return res;
+}
+
+static int add_bisect_ref(const char *refname, const struct object_id *oid,
+			  int flags, void *cb)
+{
+	struct add_bisect_ref_data *data = cb;
+
+	add_pending_oid(data->revs, refname, oid, data->object_flags);
+
+	return 0;
+}
+
+static int prepare_revs(struct bisect_terms *terms, struct rev_info *revs)
+{
+	int res = 0;
+	struct add_bisect_ref_data cb = { revs };
+	char *good = xstrfmt("%s-*", terms->term_good);
+
+	/*
+	 * We cannot use terms->term_bad directly in
+	 * for_each_glob_ref_in() and we have to append a '*' to it,
+	 * otherwise for_each_glob_ref_in() will append '/' and '*'.
+	 */
+	char *bad = xstrfmt("%s*", terms->term_bad);
+
+	/*
+	 * It is important to reset the flags used by revision walks
+	 * as the previous call to bisect_next_all() in turn
+	 * sets up a revision walk.
+	 */
+	reset_revision_walk();
+	init_revisions(revs, NULL);
+	setup_revisions(0, NULL, revs, NULL);
+	for_each_glob_ref_in(add_bisect_ref, bad, "refs/bisect/", &cb);
+	cb.object_flags = UNINTERESTING;
+	for_each_glob_ref_in(add_bisect_ref, good, "refs/bisect/", &cb);
+	if (prepare_revision_walk(revs))
+		res = error(_("revision walk setup failed\n"));
+
+	free(good);
+	free(bad);
+	return res;
 }
 
-static int bisect_start(struct bisect_terms *terms, int no_checkout,
-			const char **argv, int argc)
+static int bisect_skipped_commits(struct bisect_terms *terms)
 {
+	int res;
+	FILE *fp = NULL;
+	struct rev_info revs;
+	struct commit *commit;
+	struct pretty_print_context pp = {0};
+	struct strbuf commit_name = STRBUF_INIT;
+
+	res = prepare_revs(terms, &revs);
+	if (res)
+		return res;
+
+	fp = fopen(git_path_bisect_log(), "a");
+	if (!fp)
+		return error_errno(_("could not open '%s' for appending"),
+				  git_path_bisect_log());
+
+	if (fprintf(fp, "# only skipped commits left to test\n") < 0)
+		return error_errno(_("failed to write to '%s'"), git_path_bisect_log());
+
+	while ((commit = get_revision(&revs)) != NULL) {
+		strbuf_reset(&commit_name);
+		format_commit_message(commit, "%s",
+				      &commit_name, &pp);
+		fprintf(fp, "# possible first %s commit: [%s] %s\n",
+			terms->term_bad, oid_to_hex(&commit->object.oid),
+			commit_name.buf);
+	}
+
+	/*
+	 * Reset the flags used by revision walks in case
+	 * there is another revision walk after this one.
+	 */
+	reset_revision_walk();
+
+	strbuf_release(&commit_name);
+	fclose(fp);
+	return 0;
+}
+
+static int bisect_successful(struct bisect_terms *terms)
+{
+	struct object_id oid;
+	struct commit *commit;
+	struct pretty_print_context pp = {0};
+	struct strbuf commit_name = STRBUF_INIT;
+	char *bad_ref = xstrfmt("refs/bisect/%s",terms->term_bad);
+	int res;
+
+	read_ref(bad_ref, &oid);
+	commit = lookup_commit_reference_by_name(bad_ref);
+	format_commit_message(commit, "%s", &commit_name, &pp);
+
+	res = append_to_file(git_path_bisect_log(), "# first %s commit: [%s] %s\n",
+			    terms->term_bad, oid_to_hex(&commit->object.oid),
+			    commit_name.buf);
+
+	strbuf_release(&commit_name);
+	free(bad_ref);
+	return res;
+}
+
+static enum bisect_error bisect_next(struct bisect_terms *terms, const char *prefix)
+{
+	enum bisect_error res;
+
+	if (bisect_autostart(terms))
+		return BISECT_FAILED;
+
+	if (bisect_next_check(terms, terms->term_good))
+		return BISECT_FAILED;
+
+	/* Perform all bisection computation */
+	res = bisect_next_all(the_repository, prefix);
+
+	if (res == BISECT_INTERNAL_SUCCESS_1ST_BAD_FOUND) {
+		res = bisect_successful(terms);
+		return res ? res : BISECT_INTERNAL_SUCCESS_1ST_BAD_FOUND;
+	} else if (res == BISECT_ONLY_SKIPPED_LEFT) {
+		res = bisect_skipped_commits(terms);
+		return res ? res : BISECT_ONLY_SKIPPED_LEFT;
+	}
+	return res;
+}
+
+static enum bisect_error bisect_auto_next(struct bisect_terms *terms, const char *prefix)
+{
+	if (bisect_next_check(terms, NULL))
+		return BISECT_OK;
+
+	return bisect_next(terms, prefix);
+}
+
+static int bisect_start(struct bisect_terms *terms, const char **argv, int argc)
+{
+	int no_checkout = 0;
+	int first_parent_only = 0;
 	int i, has_double_dash = 0, must_write_terms = 0, bad_seen = 0;
-	int flags, pathspec_pos, retval = 0;
+	int flags, pathspec_pos, res = 0;
 	struct string_list revs = STRING_LIST_INIT_DUP;
 	struct string_list states = STRING_LIST_INIT_DUP;
 	struct strbuf start_head = STRBUF_INIT;
@@ -450,11 +642,16 @@ static int bisect_start(struct bisect_terms *terms, int no_checkout,
 			break;
 		} else if (!strcmp(arg, "--no-checkout")) {
 			no_checkout = 1;
+		} else if (!strcmp(arg, "--first-parent")) {
+			first_parent_only = 1;
 		} else if (!strcmp(arg, "--term-good") ||
 			 !strcmp(arg, "--term-old")) {
+			i++;
+			if (argc <= i)
+				return error(_("'' is not a valid term"));
 			must_write_terms = 1;
 			free((void *) terms->term_good);
-			terms->term_good = xstrdup(argv[++i]);
+			terms->term_good = xstrdup(argv[i]);
 		} else if (skip_prefix(arg, "--term-good=", &arg) ||
 			   skip_prefix(arg, "--term-old=", &arg)) {
 			must_write_terms = 1;
@@ -462,25 +659,26 @@ static int bisect_start(struct bisect_terms *terms, int no_checkout,
 			terms->term_good = xstrdup(arg);
 		} else if (!strcmp(arg, "--term-bad") ||
 			 !strcmp(arg, "--term-new")) {
+			i++;
+			if (argc <= i)
+				return error(_("'' is not a valid term"));
 			must_write_terms = 1;
 			free((void *) terms->term_bad);
-			terms->term_bad = xstrdup(argv[++i]);
+			terms->term_bad = xstrdup(argv[i]);
 		} else if (skip_prefix(arg, "--term-bad=", &arg) ||
 			   skip_prefix(arg, "--term-new=", &arg)) {
 			must_write_terms = 1;
 			free((void *) terms->term_bad);
 			terms->term_bad = xstrdup(arg);
-		} else if (starts_with(arg, "--") &&
-			 !one_of(arg, "--term-good", "--term-bad", NULL)) {
+		} else if (starts_with(arg, "--")) {
 			return error(_("unrecognized option: '%s'"), arg);
-		} else {
-			char *commit_id = xstrfmt("%s^{commit}", arg);
-			if (get_oid(commit_id, &oid) && has_double_dash)
-				die(_("'%s' does not appear to be a valid "
-				      "revision"), arg);
-
+		} else if (!get_oidf(&oid, "%s^{commit}", arg)) {
 			string_list_append(&revs, oid_to_hex(&oid));
-			free(commit_id);
+		} else if (has_double_dash) {
+			die(_("'%s' does not appear to be a valid "
+			      "revision"), arg);
+		} else {
+			break;
 		}
 	}
 	pathspec_pos = i;
@@ -518,12 +716,12 @@ static int bisect_start(struct bisect_terms *terms, int no_checkout,
 		strbuf_read_file(&start_head, git_path_bisect_start(), 0);
 		strbuf_trim(&start_head);
 		if (!no_checkout) {
-			struct argv_array argv = ARGV_ARRAY_INIT;
+			struct strvec argv = STRVEC_INIT;
 
-			argv_array_pushl(&argv, "checkout", start_head.buf,
-					 "--", NULL);
-			if (run_command_v_opt(argv.argv, RUN_GIT_CMD)) {
-				retval = error(_("checking out '%s' failed."
+			strvec_pushl(&argv, "checkout", start_head.buf,
+				     "--", NULL);
+			if (run_command_v_opt(argv.v, RUN_GIT_CMD)) {
+				res = error(_("checking out '%s' failed."
 						 " Try 'git bisect start "
 						 "<valid-branch>'."),
 					       start_head.buf);
@@ -569,14 +767,17 @@ static int bisect_start(struct bisect_terms *terms, int no_checkout,
 	 */
 	write_file(git_path_bisect_start(), "%s\n", start_head.buf);
 
+	if (first_parent_only)
+		write_file(git_path_bisect_first_parent(), "\n");
+
 	if (no_checkout) {
 		if (get_oid(start_head.buf, &oid) < 0) {
-			retval = error(_("invalid ref: '%s'"), start_head.buf);
+			res = error(_("invalid ref: '%s'"), start_head.buf);
 			goto finish;
 		}
 		if (update_ref(NULL, "BISECT_HEAD", &oid, NULL, 0,
 			       UPDATE_REFS_MSG_ON_ERR)) {
-			retval = -1;
+			res = -1;
 			goto finish;
 		}
 	}
@@ -588,26 +789,58 @@ static int bisect_start(struct bisect_terms *terms, int no_checkout,
 	for (i = 0; i < states.nr; i++)
 		if (bisect_write(states.items[i].string,
 				 revs.items[i].string, terms, 1)) {
-			retval = -1;
+			res = -1;
 			goto finish;
 		}
 
 	if (must_write_terms && write_terms(terms->term_bad,
 					    terms->term_good)) {
-		retval = -1;
+		res = -1;
 		goto finish;
 	}
 
-	retval = bisect_append_log_quoted(argv);
-	if (retval)
-		retval = -1;
+	res = bisect_append_log_quoted(argv);
+	if (res)
+		res = -1;
 
 finish:
 	string_list_clear(&revs, 0);
 	string_list_clear(&states, 0);
 	strbuf_release(&start_head);
 	strbuf_release(&bisect_names);
-	return retval;
+	return res;
+}
+
+static inline int file_is_not_empty(const char *path)
+{
+	return !is_empty_or_missing_file(path);
+}
+
+static int bisect_autostart(struct bisect_terms *terms)
+{
+	int res;
+	const char *yesno;
+
+	if (file_is_not_empty(git_path_bisect_start()))
+		return 0;
+
+	fprintf_ln(stderr, _("You need to start by \"git bisect "
+			  "start\"\n"));
+
+	if (!isatty(STDIN_FILENO))
+		return -1;
+
+	/*
+	 * TRANSLATORS: Make sure to include [Y] and [n] in your
+	 * translation. The program will only accept English input
+	 * at this point.
+	 */
+	yesno = git_prompt(_("Do you want me to do it for you "
+			     "[Y/n]? "), PROMPT_ECHO);
+	res = tolower(*yesno) == 'n' ?
+		-1 : bisect_start(terms, empty_strvec, 0);
+
+	return res;
 }
 
 int cmd_bisect__helper(int argc, const char **argv, const char *prefix)
@@ -622,9 +855,12 @@ int cmd_bisect__helper(int argc, const char **argv, const char *prefix)
 		CHECK_AND_SET_TERMS,
 		BISECT_NEXT_CHECK,
 		BISECT_TERMS,
-		BISECT_START
+		BISECT_START,
+		BISECT_AUTOSTART,
+		BISECT_NEXT,
+		BISECT_AUTO_NEXT
 	} cmdmode = 0;
-	int no_checkout = 0, res = 0, nolog = 0;
+	int res = 0, nolog = 0;
 	struct option options[] = {
 		OPT_CMDMODE(0, "next-all", &cmdmode,
 			 N_("perform 'git bisect next'"), NEXT_ALL),
@@ -646,8 +882,12 @@ int cmd_bisect__helper(int argc, const char **argv, const char *prefix)
 			 N_("print out the bisect terms"), BISECT_TERMS),
 		OPT_CMDMODE(0, "bisect-start", &cmdmode,
 			 N_("start the bisect session"), BISECT_START),
-		OPT_BOOL(0, "no-checkout", &no_checkout,
-			 N_("update BISECT_HEAD instead of checking out the current commit")),
+		OPT_CMDMODE(0, "bisect-next", &cmdmode,
+			 N_("find the next bisection commit"), BISECT_NEXT),
+		OPT_CMDMODE(0, "bisect-auto-next", &cmdmode,
+			 N_("verify the next bisection state then checkout the next bisection commit"), BISECT_AUTO_NEXT),
+		OPT_CMDMODE(0, "bisect-autostart", &cmdmode,
+			 N_("start the bisection if it has not yet been started"), BISECT_AUTOSTART),
 		OPT_BOOL(0, "no-log", &nolog,
 			 N_("no log for BISECT_WRITE")),
 		OPT_END()
@@ -663,7 +903,8 @@ int cmd_bisect__helper(int argc, const char **argv, const char *prefix)
 
 	switch (cmdmode) {
 	case NEXT_ALL:
-		return bisect_next_all(the_repository, prefix, no_checkout);
+		res = bisect_next_all(the_repository, prefix);
+		break;
 	case WRITE_TERMS:
 		if (argc != 2)
 			return error(_("--write-terms requires two arguments"));
@@ -704,11 +945,37 @@ int cmd_bisect__helper(int argc, const char **argv, const char *prefix)
 		break;
 	case BISECT_START:
 		set_terms(&terms, "bad", "good");
-		res = bisect_start(&terms, no_checkout, argv, argc);
+		res = bisect_start(&terms, argv, argc);
+		break;
+	case BISECT_NEXT:
+		if (argc)
+			return error(_("--bisect-next requires 0 arguments"));
+		get_terms(&terms);
+		res = bisect_next(&terms, prefix);
+		break;
+	case BISECT_AUTO_NEXT:
+		if (argc)
+			return error(_("--bisect-auto-next requires 0 arguments"));
+		get_terms(&terms);
+		res = bisect_auto_next(&terms, prefix);
+		break;
+	case BISECT_AUTOSTART:
+		if (argc)
+			return error(_("--bisect-autostart does not accept arguments"));
+		set_terms(&terms, "bad", "good");
+		res = bisect_autostart(&terms);
 		break;
 	default:
-		return error("BUG: unknown subcommand '%d'", cmdmode);
+		BUG("unknown subcommand %d", cmdmode);
 	}
 	free_terms(&terms);
-	return !!res;
+
+	/*
+	 * Handle early success
+	 * From check_merge_bases > check_good_are_ancestors_of_bad > bisect_next_all
+	 */
+	if ((res == BISECT_INTERNAL_SUCCESS_MERGE_BASE) || (res == BISECT_INTERNAL_SUCCESS_1ST_BAD_FOUND))
+		res = BISECT_OK;
+
+	return -res;
 }