From 36b543b5c9686a65bd628fe1115476253e5e5e55 Mon Sep 17 00:00:00 2001
From: Miriam Rubio <mirucam@gmail.com>
Date: Thu, 23 Apr 2020 09:06:53 +0200
Subject: [PATCH 01/12] bisect--helper: fix `cmd_*()` function switch default
 return

In a `cmd_*()` function, return `error()` cannot be used
because that translates to `-1` and `cmd_*()` functions need
to return exit codes.

Let's fix switch default return.

Mentored-by: Christian Couder <chriscool@tuxfamily.org>
Mentored-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: Miriam Rubio <mirucam@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 builtin/bisect--helper.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/builtin/bisect--helper.c b/builtin/bisect--helper.c
index c1c40b516d..a81a2c76ff 100644
--- a/builtin/bisect--helper.c
+++ b/builtin/bisect--helper.c
@@ -711,7 +711,7 @@ int cmd_bisect__helper(int argc, const char **argv, const char *prefix)
 		res = bisect_start(&terms, no_checkout, argv, argc);
 		break;
 	default:
-		return error("BUG: unknown subcommand '%d'", cmdmode);
+		BUG("unknown subcommand %d", (int)cmdmode);
 	}
 	free_terms(&terms);
 

From ab664393dad3ad80d64549707b49c1e063473195 Mon Sep 17 00:00:00 2001
From: Miriam Rubio <mirucam@gmail.com>
Date: Thu, 23 Apr 2020 09:06:54 +0200
Subject: [PATCH 02/12] bisect--helper: use '-res' in 'cmd_bisect__helper'
 return

Following 'enum bisect_error' vocabulary, return variable 'res' is
always non-positive.
Let's use '-res' instead of 'abs(res)' to make the code clearer.

Mentored-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Miriam Rubio <mirucam@gmail.com>
Helped-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 builtin/bisect--helper.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/builtin/bisect--helper.c b/builtin/bisect--helper.c
index a81a2c76ff..0fbd924aac 100644
--- a/builtin/bisect--helper.c
+++ b/builtin/bisect--helper.c
@@ -722,5 +722,5 @@ int cmd_bisect__helper(int argc, const char **argv, const char *prefix)
 	if (res == BISECT_INTERNAL_SUCCESS_MERGE_BASE)
 		res = BISECT_OK;
 
-	return abs(res);
+	return -res;
 }

From 9aadf776e3c9b2d1c3742b50ce706cc5b086e4fe Mon Sep 17 00:00:00 2001
From: Miriam Rubio <mirucam@gmail.com>
Date: Thu, 23 Apr 2020 09:06:55 +0200
Subject: [PATCH 03/12] bisect--helper: introduce new `write_in_file()`
 function

Let's refactor code adding a new `write_in_file()` function
that opens a file for writing a message and closes it.

This helper will be used in later steps and makes the code
simpler and easier to understand.

Mentored-by: Christian Couder <chriscool@tuxfamily.org>
Mentored-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: Miriam Rubio <mirucam@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 builtin/bisect--helper.c | 29 +++++++++++++++++++++++------
 1 file changed, 23 insertions(+), 6 deletions(-)

diff --git a/builtin/bisect--helper.c b/builtin/bisect--helper.c
index 0fbd924aac..d3b2b33df0 100644
--- a/builtin/bisect--helper.c
+++ b/builtin/bisect--helper.c
@@ -74,6 +74,28 @@ static int one_of(const char *term, ...)
 	return res;
 }
 
+static int write_in_file(const char *path, const char *mode, const char *format,...)
+{
+	FILE *fp = NULL;
+	va_list args;
+	int res = 0;
+
+	if (!strcmp(mode, "a") && !strcmp(mode, "w"))
+		return error(_("wrong writing mode '%s'"), mode);
+	fp = fopen(path, mode);
+	if (!fp)
+		return error_errno(_("cannot open file '%s' in mode '%s'"), path, mode);
+	va_start(args, format);
+	res = vfprintf(fp, format, args);
+	va_end(args);
+	if (!res) {
+		fclose(fp);
+		return error_errno(_("could not write to file '%s'"), path);
+	}
+
+	return fclose(fp);
+}
+
 static int check_term_format(const char *term, const char *orig_term)
 {
 	int res;
@@ -104,7 +126,6 @@ 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))
@@ -113,12 +134,8 @@ 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_in_file(git_path_bisect_terms(), "w", "%s\n%s\n", bad, good);
 
-	res = fprintf(fp, "%s\n%s\n", bad, good);
-	res |= fclose(fp);
 	return (res < 0) ? -1 : 0;
 }
 

From 05a69202bb7a80897adad95324a9c2932fb5a5e0 Mon Sep 17 00:00:00 2001
From: Pranit Bauva <pranit.bauva@gmail.com>
Date: Thu, 23 Apr 2020 09:06:56 +0200
Subject: [PATCH 04/12] bisect--helper: reimplement `bisect_autostart` shell
 function in C

Reimplement the `bisect_autostart()` shell function in C and add the
C implementation from `bisect_next()` which was previously left
uncovered. Also add a subcommand `--bisect-autostart` to
`git bisect--helper` be called from `bisect_state()` from
git-bisect.sh .

Using `--bisect-autostart` subcommand is a temporary measure to port
shell function to C so as to use the existing test suite. As more
functions are ported, this subcommand will be retired and
bisect_autostart() will be called directly by `bisect_state()`.

Mentored-by: Lars Schneider <larsxschneider@gmail.com>
Mentored-by: Christian Couder <chriscool@tuxfamily.org>
Mentored-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Pranit Bauva <pranit.bauva@gmail.com>
Signed-off-by: Tanushree Tumane <tanushreetumane@gmail.com>
Signed-off-by: Miriam Rubio <mirucam@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 builtin/bisect--helper.c | 40 +++++++++++++++++++++++++++++++++++++++-
 git-bisect.sh            | 25 ++-----------------------
 2 files changed, 41 insertions(+), 24 deletions(-)

diff --git a/builtin/bisect--helper.c b/builtin/bisect--helper.c
index d3b2b33df0..9df69800e3 100644
--- a/builtin/bisect--helper.c
+++ b/builtin/bisect--helper.c
@@ -29,6 +29,7 @@ static const char * const git_bisect_helper_usage[] = {
 	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-autostart"),
 	NULL
 };
 
@@ -55,6 +56,8 @@ static void set_terms(struct bisect_terms *terms, const char *bad,
 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
  * included in the variable arguments.
@@ -630,6 +633,32 @@ finish:
 	return res;
 }
 
+static int bisect_autostart(struct bisect_terms *terms)
+{
+	const char *yesno;
+
+	if (!is_empty_or_missing_file(git_path_bisect_start()))
+		return 0;
+
+	fprintf(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);
+	if (starts_with(yesno, _("n")) || starts_with(yesno, _("N")))
+		return 1;
+
+	return bisect_start(terms, 0, NULL, 0);
+}
+
 int cmd_bisect__helper(int argc, const char **argv, const char *prefix)
 {
 	enum {
@@ -642,7 +671,8 @@ 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,
 	} cmdmode = 0;
 	int no_checkout = 0, res = 0, nolog = 0;
 	struct option options[] = {
@@ -666,6 +696,8 @@ 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_CMDMODE(0, "bisect-autostart", &cmdmode,
+			 N_("start the bisection if BISECT_START is empty or missing"), BISECT_AUTOSTART),
 		OPT_BOOL(0, "no-checkout", &no_checkout,
 			 N_("update BISECT_HEAD instead of checking out the current commit")),
 		OPT_BOOL(0, "no-log", &nolog,
@@ -727,6 +759,12 @@ int cmd_bisect__helper(int argc, const char **argv, const char *prefix)
 		set_terms(&terms, "bad", "good");
 		res = bisect_start(&terms, no_checkout, argv, argc);
 		break;
+	case BISECT_AUTOSTART:
+		if (argc)
+			return error(_("--bisect-autostart requires 0 arguments"));
+		set_terms(&terms, "bad", "good");
+		res = bisect_autostart(&terms);
+		break;
 	default:
 		BUG("unknown subcommand %d", (int)cmdmode);
 	}
diff --git a/git-bisect.sh b/git-bisect.sh
index efee12b8b1..426d443e7e 100755
--- a/git-bisect.sh
+++ b/git-bisect.sh
@@ -49,27 +49,6 @@ bisect_head()
 	fi
 }
 
-bisect_autostart() {
-	test -s "$GIT_DIR/BISECT_START" || {
-		gettextln "You need to start by \"git bisect start\"" >&2
-		if test -t 0
-		then
-			# TRANSLATORS: Make sure to include [Y] and [n] in your
-			# translation. The program will only accept English input
-			# at this point.
-			gettext "Do you want me to do it for you [Y/n]? " >&2
-			read yesno
-			case "$yesno" in
-			[Nn]*)
-				exit ;;
-			esac
-			bisect_start
-		else
-			exit 1
-		fi
-	}
-}
-
 bisect_start() {
 	git bisect--helper --bisect-start $@ || exit
 
@@ -108,7 +87,7 @@ bisect_skip() {
 }
 
 bisect_state() {
-	bisect_autostart
+	git bisect--helper --bisect-autostart
 	state=$1
 	git bisect--helper --check-and-set-terms $state $TERM_GOOD $TERM_BAD || exit
 	get_terms
@@ -149,7 +128,7 @@ bisect_auto_next() {
 
 bisect_next() {
 	case "$#" in 0) ;; *) usage ;; esac
-	bisect_autostart
+	git bisect--helper --bisect-autostart
 	git bisect--helper --bisect-next-check $TERM_GOOD $TERM_BAD $TERM_GOOD|| exit
 
 	# Perform all bisection computation, display and checkout

From 587c9facd3d1318981ac357963f30311dc899604 Mon Sep 17 00:00:00 2001
From: Pranit Bauva <pranit.bauva@gmail.com>
Date: Thu, 23 Apr 2020 09:06:57 +0200
Subject: [PATCH 05/12] bisect--helper: reimplement `bisect_next` and
 `bisect_auto_next` shell functions in C

Reimplement the `bisect_next()` and the `bisect_auto_next()` shell functions
in C and add the subcommands to `git bisect--helper` to call them from
git-bisect.sh .

bisect_auto_next() function returns an enum bisect_error type as whole
`git bisect` can exit with an error code when bisect_next() does.

Using `--bisect-next` and `--bisect-auto-next` subcommands is a
temporary measure to port shell function to C so as to use the existing
test suite. As more functions are ported, `--bisect-auto-next`
subcommand will be retired and will be called by some other methods.

Mentored-by: Lars Schneider <larsxschneider@gmail.com>
Mentored-by: Christian Couder <chriscool@tuxfamily.org>
Mentored-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: Pranit Bauva <pranit.bauva@gmail.com>
Signed-off-by: Tanushree Tumane <tanushreetumane@gmail.com>
Signed-off-by: Miriam Rubio <mirucam@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 bisect.c                 |   8 ++
 builtin/bisect--helper.c | 169 ++++++++++++++++++++++++++++++++++++++-
 git-bisect.sh            |  47 +----------
 3 files changed, 179 insertions(+), 45 deletions(-)

diff --git a/bisect.c b/bisect.c
index 9154f810f7..31cab3f0b0 100644
--- a/bisect.c
+++ b/bisect.c
@@ -980,6 +980,12 @@ void read_bisect_terms(const char **read_bad, const char **read_good)
  * the bisection process finished successfully.
  * In this case the calling function or command should not turn a
  * BISECT_INTERNAL_SUCCESS_1ST_BAD_FOUND return code into an error or a non zero exit code.
+ *
+ * Checking BISECT_INTERNAL_SUCCESS_1ST_BAD_FOUND
+ * in bisect_helper::bisect_next() and only transforming it to 0 at
+ * the end of bisect_helper::cmd_bisect__helper() helps bypassing
+ * all the code related to finding a commit to test.
+ *
  * If no_checkout is non-zero, the bisection process does not
  * checkout the trial commit but instead simply updates BISECT_HEAD.
  */
@@ -1064,6 +1070,8 @@ enum bisect_error bisect_next_all(struct repository *r, const char *prefix, int
 		  "Bisecting: %d revisions left to test after this %s\n",
 		  nr), nr, steps_msg);
 	free(steps_msg);
+	/* Clean up objects used, as they will be reused. */
+	clear_commit_marks_all(ALL_REV_FLAGS);
 
 	return bisect_checkout(bisect_rev, no_checkout);
 }
diff --git a/builtin/bisect--helper.c b/builtin/bisect--helper.c
index 9df69800e3..c6aaa8eb15 100644
--- a/builtin/bisect--helper.c
+++ b/builtin/bisect--helper.c
@@ -8,6 +8,7 @@
 #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")
@@ -29,6 +30,8 @@ static const char * const git_bisect_helper_usage[] = {
 	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-next"),
+	N_("git bisect--helper --bisect-auto-next"),
 	N_("git bisect--helper --bisect-autostart"),
 	NULL
 };
@@ -441,6 +444,150 @@ finish:
 	return res;
 }
 
+static int register_good_ref(const char *refname,
+			     const struct object_id *oid, int flags,
+			     void *cb_data)
+{
+	struct argv_array *rev_argv = cb_data;
+
+	argv_array_push(rev_argv, oid_to_hex(oid));
+	return 0;
+}
+
+static void prepare_rev_argv(struct bisect_terms *terms, struct argv_array *rev_argv)
+{
+	char *term_good = xstrfmt("%s-*", terms->term_good);
+
+	argv_array_pushl(rev_argv, "skipped_commits", "refs/bisect/bad", "--not", NULL);
+	for_each_glob_ref_in(register_good_ref, term_good, "refs/bisect/", rev_argv);
+
+	free(term_good);
+}
+
+static int prepare_revs(struct bisect_terms *terms, struct rev_info *revs)
+{
+	int res = 0;
+	struct argv_array rev_argv = ARGV_ARRAY_INIT;
+
+	prepare_rev_argv(terms, &rev_argv);
+
+	/*
+	 * 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);
+	rev_argv.argc = setup_revisions(rev_argv.argc, rev_argv.argv, revs, NULL);
+	if (prepare_revision_walk(revs))
+		res = error(_("revision walk setup failed\n"));
+
+	argv_array_clear(&rev_argv);
+	return res;
+}
+
+static int process_skipped_commits(FILE *fp, struct bisect_terms *terms, struct rev_info *revs)
+{
+	struct commit *commit;
+	struct pretty_print_context pp = {0};
+
+	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) {
+		struct strbuf commit_name = STRBUF_INIT;
+		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);
+		strbuf_release(&commit_name);
+	}
+
+	/*
+	 * Reset the flags used by revision walks in case
+	 * there is another revision walk after this one.
+	 */
+	reset_revision_walk();
+
+	return 0;
+}
+
+static int bisect_skipped_commits(struct bisect_terms *terms)
+{
+	int res = 0;
+	FILE *fp = NULL;
+	struct rev_info revs;
+
+	fp = fopen(git_path_bisect_log(), "a");
+	if (!fp)
+		return error_errno(_("could not open '%s' for appending"),
+				  git_path_bisect_log());
+
+	res = prepare_revs(terms, &revs);
+
+	if (!res)
+		res = process_skipped_commits(fp, terms, &revs);
+
+	fclose(fp);
+	return res;
+}
+
+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);
+	printf("%s\n", bad_ref);
+	commit = lookup_commit_reference(the_repository, &oid);
+	format_commit_message(commit, "%s", &commit_name, &pp);
+
+	res = write_in_file(git_path_bisect_log(), "a", "# first %s commit: [%s] %s\n",
+			    terms->term_bad, oid_to_hex(&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)
+{
+	int no_checkout;
+	enum bisect_error res;
+
+	bisect_autostart(terms);
+	if (bisect_next_check(terms, terms->term_good))
+		return BISECT_FAILED;
+
+	no_checkout = file_exists(git_path_bisect_head());
+
+	/* Perform all bisection computation, display and checkout */
+	res = bisect_next_all(the_repository, prefix, no_checkout);
+
+	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, int no_checkout,
 			const char **argv, int argc)
 {
@@ -672,7 +819,9 @@ int cmd_bisect__helper(int argc, const char **argv, const char *prefix)
 		BISECT_NEXT_CHECK,
 		BISECT_TERMS,
 		BISECT_START,
-		BISECT_AUTOSTART,
+		BISECT_NEXT,
+		BISECT_AUTO_NEXT,
+		BISECT_AUTOSTART
 	} cmdmode = 0;
 	int no_checkout = 0, res = 0, nolog = 0;
 	struct option options[] = {
@@ -696,6 +845,10 @@ 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_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 BISECT_START is empty or missing"), BISECT_AUTOSTART),
 		OPT_BOOL(0, "no-checkout", &no_checkout,
@@ -759,6 +912,18 @@ int cmd_bisect__helper(int argc, const char **argv, const char *prefix)
 		set_terms(&terms, "bad", "good");
 		res = bisect_start(&terms, no_checkout, 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 requires 0 arguments"));
@@ -774,7 +939,7 @@ int cmd_bisect__helper(int argc, const char **argv, const char *prefix)
 	 * Handle early success
 	 * From check_merge_bases > check_good_are_ancestors_of_bad > bisect_next_all
 	 */
-	if (res == BISECT_INTERNAL_SUCCESS_MERGE_BASE)
+	if ((res == BISECT_INTERNAL_SUCCESS_MERGE_BASE) || (res == BISECT_INTERNAL_SUCCESS_1ST_BAD_FOUND))
 		res = BISECT_OK;
 
 	return -res;
diff --git a/git-bisect.sh b/git-bisect.sh
index 426d443e7e..897825b675 100755
--- a/git-bisect.sh
+++ b/git-bisect.sh
@@ -65,8 +65,7 @@ bisect_start() {
 	#
 	# Check if we can proceed to the next bisect state.
 	#
-	get_terms
-	bisect_auto_next
+	git bisect--helper --bisect-auto-next || exit
 
 	trap '-' 0
 }
@@ -119,45 +118,7 @@ bisect_state() {
 	*)
 		usage ;;
 	esac
-	bisect_auto_next
-}
-
-bisect_auto_next() {
-	git bisect--helper --bisect-next-check $TERM_GOOD $TERM_BAD && bisect_next || :
-}
-
-bisect_next() {
-	case "$#" in 0) ;; *) usage ;; esac
-	git bisect--helper --bisect-autostart
-	git bisect--helper --bisect-next-check $TERM_GOOD $TERM_BAD $TERM_GOOD|| exit
-
-	# Perform all bisection computation, display and checkout
-	git bisect--helper --next-all $(test -f "$GIT_DIR/BISECT_HEAD" && echo --no-checkout)
-	res=$?
-
-	# Check if we should exit because bisection is finished
-	if test $res -eq 10
-	then
-		bad_rev=$(git show-ref --hash --verify refs/bisect/$TERM_BAD)
-		bad_commit=$(git show-branch $bad_rev)
-		echo "# first $TERM_BAD commit: $bad_commit" >>"$GIT_DIR/BISECT_LOG"
-		exit 0
-	elif test $res -eq 2
-	then
-		echo "# only skipped commits left to test" >>"$GIT_DIR/BISECT_LOG"
-		good_revs=$(git for-each-ref --format="%(objectname)" "refs/bisect/$TERM_GOOD-*")
-		for skipped in $(git rev-list refs/bisect/$TERM_BAD --not $good_revs)
-		do
-			skipped_commit=$(git show-branch $skipped)
-			echo "# possible first $TERM_BAD commit: $skipped_commit" >>"$GIT_DIR/BISECT_LOG"
-		done
-		exit $res
-	fi
-
-	# Check for an error in the bisection process
-	test $res -ne 0 && exit $res
-
-	return 0
+	git bisect--helper --bisect-auto-next
 }
 
 bisect_visualize() {
@@ -211,7 +172,7 @@ bisect_replay () {
 			die "$(gettext "?? what are you talking about?")" ;;
 		esac
 	done <"$file"
-	bisect_auto_next
+	git bisect--helper --bisect-auto-next
 }
 
 bisect_run () {
@@ -308,7 +269,7 @@ case "$#" in
 		bisect_skip "$@" ;;
 	next)
 		# Not sure we want "next" at the UI level anymore.
-		bisect_next "$@" ;;
+		git bisect--helper --bisect-next "$@" || exit ;;
 	visualize|view)
 		bisect_visualize "$@" ;;
 	reset)

From f0bf9482998aad3a41c053168e96af078a65443b Mon Sep 17 00:00:00 2001
From: Pranit Bauva <pranit.bauva@gmail.com>
Date: Thu, 23 Apr 2020 09:06:58 +0200
Subject: [PATCH 06/12] bisect--helper: finish porting `bisect_start()` to C

Add the subcommand to `git bisect--helper` and call it from
git-bisect.sh.

With the conversion of `bisect_auto_next()` from shell to C in a
previous commit, `bisect_start()` can now be fully ported to C.

So let's complete the `--bisect-start` subcommand of
`git bisect--helper` so that it fully implements `bisect_start()`,
and let's use this subcommand in `git-bisect.sh` instead of
`bisect_start()`.

This removes the signal handling we had in `bisect_start()` as we
don't really need it. While at it, "trap" is changed to "handle".
As "trap" is a reference to the shell "trap" builtin, which isn't
used anymore.

Mentored-by: Christian Couder <chriscool@tuxfamily.org>
Mentored-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: Pranit Bauva <pranit.bauva@gmail.com>
Signed-off-by: Tanushree Tumane <tanushreetumane@gmail.com>
Signed-off-by: Miriam Rubio <mirucam@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 builtin/bisect--helper.c | 54 +++++++++++++++++++++++++++++++---------
 git-bisect.sh            | 26 ++-----------------
 2 files changed, 44 insertions(+), 36 deletions(-)

diff --git a/builtin/bisect--helper.c b/builtin/bisect--helper.c
index c6aaa8eb15..f2ec7f89e4 100644
--- a/builtin/bisect--helper.c
+++ b/builtin/bisect--helper.c
@@ -588,11 +588,12 @@ static enum bisect_error bisect_auto_next(struct bisect_terms *terms, const char
 	return bisect_next(terms, prefix);
 }
 
-static int bisect_start(struct bisect_terms *terms, int no_checkout,
+static enum bisect_error bisect_start(struct bisect_terms *terms, int no_checkout,
 			const char **argv, int argc)
 {
 	int i, has_double_dash = 0, must_write_terms = 0, bad_seen = 0;
-	int flags, pathspec_pos, res = 0;
+	int flags, pathspec_pos;
+	enum bisect_error res = BISECT_OK;
 	struct string_list revs = STRING_LIST_INIT_DUP;
 	struct string_list states = STRING_LIST_INIT_DUP;
 	struct strbuf start_head = STRBUF_INIT;
@@ -645,9 +646,12 @@ static int bisect_start(struct bisect_terms *terms, int no_checkout,
 			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);
+			if (get_oid(commit_id, &oid) && has_double_dash) {
+				error(_("'%s' does not appear to be a valid "
+					"revision"), arg);
+				free(commit_id);
+				return BISECT_FAILED;
+			}
 
 			string_list_append(&revs, oid_to_hex(&oid));
 			free(commit_id);
@@ -725,12 +729,12 @@ static int bisect_start(struct bisect_terms *terms, int no_checkout,
 	 * Get rid of any old bisect state.
 	 */
 	if (bisect_clean_state())
-		return -1;
+		return BISECT_FAILED;
 
 	/*
-	 * In case of mistaken revs or checkout error, or signals received,
+	 * In case of mistaken revs or checkout error,
 	 * "bisect_auto_next" below may exit or misbehave.
-	 * We have to trap this to be able to clean up using
+	 * We have to handle this to be able to clean up using
 	 * "bisect_clean_state".
 	 */
 
@@ -746,7 +750,7 @@ static int bisect_start(struct bisect_terms *terms, int no_checkout,
 		}
 		if (update_ref(NULL, "BISECT_HEAD", &oid, NULL, 0,
 			       UPDATE_REFS_MSG_ON_ERR)) {
-			res = -1;
+			res = BISECT_FAILED;
 			goto finish;
 		}
 	}
@@ -758,25 +762,51 @@ 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)) {
-			res = -1;
+			res = BISECT_FAILED;
 			goto finish;
 		}
 
 	if (must_write_terms && write_terms(terms->term_bad,
 					    terms->term_good)) {
-		res = -1;
+		res = BISECT_FAILED;
 		goto finish;
 	}
 
 	res = bisect_append_log_quoted(argv);
 	if (res)
-		res = -1;
+		res = BISECT_FAILED;
 
 finish:
 	string_list_clear(&revs, 0);
 	string_list_clear(&states, 0);
 	strbuf_release(&start_head);
 	strbuf_release(&bisect_names);
+	if (res)
+		return res;
+
+	res = bisect_auto_next(terms, NULL);
+	/*
+	 * In case of mistaken revs or checkout error, or signals received,
+	 * "bisect_auto_next" below may exit or misbehave.
+	 * We have to handle this to be able to clean up using
+	 * "bisect_clean_state".
+	 * return code BISECT_INTERNAL_SUCCESS_MERGE_BASE is special code
+	 * that indicates special success.
+	 *	-> bisect_start()
+	 *	   . res = bisect_auto_next()
+	 *	    -> bisect_auto_next()
+	 *	       . return bisect_next()
+	 *	       -> bisect_next()
+	 *		  . res = bisect_next_all()
+	 *		  -> bisect_next_all()
+	 *		     . res = check_good_are_ancestors_of_bad()
+	 *		     -> check_good_are_ancestors_of_bad()
+	 *			. res = check_merge_bases()
+	 *			-> check_merge_bases()
+	 *			   . res = BISECT_INTERNAL_SUCCESS_MERGE_BASE
+	 */
+	if (res && res != BISECT_INTERNAL_SUCCESS_MERGE_BASE)
+		bisect_clean_state();
 	return res;
 }
 
diff --git a/git-bisect.sh b/git-bisect.sh
index 897825b675..049ffacdff 100755
--- a/git-bisect.sh
+++ b/git-bisect.sh
@@ -49,27 +49,6 @@ bisect_head()
 	fi
 }
 
-bisect_start() {
-	git bisect--helper --bisect-start $@ || exit
-
-	#
-	# Change state.
-	# In case of mistaken revs or checkout error, or signals received,
-	# "bisect_auto_next" below may exit or misbehave.
-	# We have to trap this to be able to clean up using
-	# "bisect_clean_state".
-	#
-	trap 'git bisect--helper --bisect-clean-state' 0
-	trap 'exit 255' 1 2 3 15
-
-	#
-	# Check if we can proceed to the next bisect state.
-	#
-	git bisect--helper --bisect-auto-next || exit
-
-	trap '-' 0
-}
-
 bisect_skip() {
 	all=''
 	for arg in "$@"
@@ -162,8 +141,7 @@ bisect_replay () {
 		get_terms
 		case "$command" in
 		start)
-			cmd="bisect_start $rev"
-			eval "$cmd" ;;
+			eval "git bisect--helper --bisect-start $rev" ;;
 		"$TERM_GOOD"|"$TERM_BAD"|skip)
 			git bisect--helper --bisect-write "$command" "$rev" "$TERM_GOOD" "$TERM_BAD" || exit;;
 		terms)
@@ -262,7 +240,7 @@ case "$#" in
 	help)
 		git bisect -h ;;
 	start)
-		bisect_start "$@" ;;
+		git bisect--helper --bisect-start "$@" ;;
 	bad|good|new|old|"$TERM_BAD"|"$TERM_GOOD")
 		bisect_state "$cmd" "$@" ;;
 	skip)

From 0fd0dc136d9e5b6ce3cf71dd6c2b656a513a997a Mon Sep 17 00:00:00 2001
From: Pranit Bauva <pranit.bauva@gmail.com>
Date: Thu, 23 Apr 2020 09:06:59 +0200
Subject: [PATCH 07/12] bisect--helper: retire `--bisect-clean-state`
 subcommand

The `--bisect-clean-state` subcommand is no longer used from the
git-bisect.sh shell script. Instead the function
`bisect_clean_state()` is directly called from the C
implementation.

Mentored-by: Lars Schneider <larsxschneider@gmail.com>
Mentored-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Pranit Bauva <pranit.bauva@gmail.com>
Signed-off-by: Tanushree Tumane <tanushreetumane@gmail.com>
Signed-off-by: Miriam Rubio <mirucam@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 builtin/bisect--helper.c | 8 --------
 1 file changed, 8 deletions(-)

diff --git a/builtin/bisect--helper.c b/builtin/bisect--helper.c
index f2ec7f89e4..1b4d0a0f87 100644
--- a/builtin/bisect--helper.c
+++ b/builtin/bisect--helper.c
@@ -22,7 +22,6 @@ static GIT_PATH_FUNC(git_path_bisect_names, "BISECT_NAMES")
 static const char * const git_bisect_helper_usage[] = {
 	N_("git bisect--helper --next-all [--no-checkout]"),
 	N_("git bisect--helper --write-terms <bad_term> <good_term>"),
-	N_("git bisect--helper --bisect-clean-state"),
 	N_("git bisect--helper --bisect-reset [<commit>]"),
 	N_("git bisect--helper --bisect-write [--no-log] <state> <revision> <good_term> <bad_term>"),
 	N_("git bisect--helper --bisect-check-and-set-terms <command> <good_term> <bad_term>"),
@@ -841,7 +840,6 @@ int cmd_bisect__helper(int argc, const char **argv, const char *prefix)
 	enum {
 		NEXT_ALL = 1,
 		WRITE_TERMS,
-		BISECT_CLEAN_STATE,
 		CHECK_EXPECTED_REVS,
 		BISECT_RESET,
 		BISECT_WRITE,
@@ -859,8 +857,6 @@ int cmd_bisect__helper(int argc, const char **argv, const char *prefix)
 			 N_("perform 'git bisect next'"), NEXT_ALL),
 		OPT_CMDMODE(0, "write-terms", &cmdmode,
 			 N_("write the terms to .git/BISECT_TERMS"), WRITE_TERMS),
-		OPT_CMDMODE(0, "bisect-clean-state", &cmdmode,
-			 N_("cleanup the bisection state"), BISECT_CLEAN_STATE),
 		OPT_CMDMODE(0, "check-expected-revs", &cmdmode,
 			 N_("check for expected revs"), CHECK_EXPECTED_REVS),
 		OPT_CMDMODE(0, "bisect-reset", &cmdmode,
@@ -904,10 +900,6 @@ int cmd_bisect__helper(int argc, const char **argv, const char *prefix)
 		if (argc != 2)
 			return error(_("--write-terms requires two arguments"));
 		return write_terms(argv[0], argv[1]);
-	case BISECT_CLEAN_STATE:
-		if (argc != 0)
-			return error(_("--bisect-clean-state requires no arguments"));
-		return bisect_clean_state();
 	case CHECK_EXPECTED_REVS:
 		check_expected_revs(argv, argc);
 		return 0;

From 043dc35d7199b9fa1ac5c38b91164a32ba8cfe16 Mon Sep 17 00:00:00 2001
From: Pranit Bauva <pranit.bauva@gmail.com>
Date: Thu, 23 Apr 2020 09:07:00 +0200
Subject: [PATCH 08/12] bisect--helper: retire `--next-all` subcommand

The `--next-all` subcommand is no longer used from the git-bisect.sh
shell script. Instead the function `bisect_next_all()` is called from
the C implementation of `bisect_next()`.

Mentored-by: Lars Schneider <larsxschneider@gmail.com>
Mentored-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Pranit Bauva <pranit.bauva@gmail.com>
Signed-off-by: Tanushree Tumane <tanushreetumane@gmail.com>
Signed-off-by: Miriam Rubio <mirucam@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 builtin/bisect--helper.c | 9 +--------
 1 file changed, 1 insertion(+), 8 deletions(-)

diff --git a/builtin/bisect--helper.c b/builtin/bisect--helper.c
index 1b4d0a0f87..2d8660c79f 100644
--- a/builtin/bisect--helper.c
+++ b/builtin/bisect--helper.c
@@ -20,7 +20,6 @@ static GIT_PATH_FUNC(git_path_head_name, "head-name")
 static GIT_PATH_FUNC(git_path_bisect_names, "BISECT_NAMES")
 
 static const char * const git_bisect_helper_usage[] = {
-	N_("git bisect--helper --next-all [--no-checkout]"),
 	N_("git bisect--helper --write-terms <bad_term> <good_term>"),
 	N_("git bisect--helper --bisect-reset [<commit>]"),
 	N_("git bisect--helper --bisect-write [--no-log] <state> <revision> <good_term> <bad_term>"),
@@ -838,8 +837,7 @@ static int bisect_autostart(struct bisect_terms *terms)
 int cmd_bisect__helper(int argc, const char **argv, const char *prefix)
 {
 	enum {
-		NEXT_ALL = 1,
-		WRITE_TERMS,
+		WRITE_TERMS = 1,
 		CHECK_EXPECTED_REVS,
 		BISECT_RESET,
 		BISECT_WRITE,
@@ -853,8 +851,6 @@ int cmd_bisect__helper(int argc, const char **argv, const char *prefix)
 	} cmdmode = 0;
 	int no_checkout = 0, res = 0, nolog = 0;
 	struct option options[] = {
-		OPT_CMDMODE(0, "next-all", &cmdmode,
-			 N_("perform 'git bisect next'"), NEXT_ALL),
 		OPT_CMDMODE(0, "write-terms", &cmdmode,
 			 N_("write the terms to .git/BISECT_TERMS"), WRITE_TERMS),
 		OPT_CMDMODE(0, "check-expected-revs", &cmdmode,
@@ -893,9 +889,6 @@ int cmd_bisect__helper(int argc, const char **argv, const char *prefix)
 		usage_with_options(git_bisect_helper_usage, options);
 
 	switch (cmdmode) {
-	case NEXT_ALL:
-		res = bisect_next_all(the_repository, prefix, no_checkout);
-		break;
 	case WRITE_TERMS:
 		if (argc != 2)
 			return error(_("--write-terms requires two arguments"));

From 10520dbf01d8f3244dc8708102a683073303a347 Mon Sep 17 00:00:00 2001
From: Pranit Bauva <pranit.bauva@gmail.com>
Date: Thu, 23 Apr 2020 09:07:01 +0200
Subject: [PATCH 09/12] bisect--helper: reimplement `bisect_state` &
 `bisect_head` shell functions in C

Reimplement the `bisect_state()` shell functions in C and also add a
subcommand `--bisect-state` to `git-bisect--helper` to call them from
git-bisect.sh .

Using `--bisect-state` subcommand is a temporary measure to port shell
function to C so as to use the existing test suite. As more functions
are ported, this subcommand will be retired and will be called by some
other methods.

`bisect_head()` is only called from `bisect_state()`, thus it is not
required to introduce another subcommand.

Mentored-by: Lars Schneider <larsxschneider@gmail.com>
Mentored-by: Christian Couder <chriscool@tuxfamily.org>
Mentored-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: Pranit Bauva <pranit.bauva@gmail.com>
Signed-off-by: Tanushree Tumane <tanushreetumane@gmail.com>
Signed-off-by: Miriam Rubio <mirucam@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 builtin/bisect--helper.c | 70 +++++++++++++++++++++++++++++++++++++++-
 git-bisect.sh            | 55 +++----------------------------
 2 files changed, 73 insertions(+), 52 deletions(-)

diff --git a/builtin/bisect--helper.c b/builtin/bisect--helper.c
index 2d8660c79f..9db72f5891 100644
--- a/builtin/bisect--helper.c
+++ b/builtin/bisect--helper.c
@@ -31,6 +31,8 @@ static const char * const git_bisect_helper_usage[] = {
 	N_("git bisect--helper --bisect-next"),
 	N_("git bisect--helper --bisect-auto-next"),
 	N_("git bisect--helper --bisect-autostart"),
+	N_("git bisect--helper --bisect-state (bad|new) [<rev>]"),
+	N_("git bisect--helper --bisect-state (good|old) [<rev>...]"),
 	NULL
 };
 
@@ -834,6 +836,64 @@ static int bisect_autostart(struct bisect_terms *terms)
 	return bisect_start(terms, 0, NULL, 0);
 }
 
+static int bisect_head(struct object_id *oid)
+{
+	if (!file_exists(git_path_bisect_head()))
+		return get_oid("HEAD", oid);
+
+	return get_oid("BISECT_HEAD", oid);
+}
+
+static enum bisect_error bisect_state(struct bisect_terms *terms, const char **argv,
+			int argc)
+{
+	const char *state;
+	const char *hex;
+	int i;
+	struct oid_array revs = OID_ARRAY_INIT;
+	struct object_id oid;
+
+	if (!argc)
+		return error(_("Please call `--bisect-state` with at least one argument"));
+	state = argv[0];
+	if (check_and_set_terms(terms, state) ||
+	    !one_of(state, terms->term_good,terms->term_bad, "skip", NULL))
+		return BISECT_FAILED;
+	argv++;
+	argc--;
+	if (!strcmp(state, terms->term_bad) && (argc > 1))
+		return error(_("'git bisect %s' can take only one argument."),terms->term_bad);
+	if (argc == 0) {
+		if (bisect_head(&oid))
+			return error(_("Bad bisect_head rev input"));
+		hex = oid_to_hex(&oid);
+		if (bisect_write(state, hex, terms, 0))
+			return BISECT_FAILED;
+		check_expected_revs(&hex, 1);
+		return bisect_auto_next(terms, NULL);
+	}
+
+	/* Here argc > 0 */
+	for (; argc; argc--, argv++) {
+		struct object_id oid;
+		if (get_oid(*argv, &oid))
+			return error(_("Bad rev input: %s"), *argv);
+		oid_array_append(&revs, &oid);
+	}
+
+	for (i = 0; i < revs.nr; i++) {
+		hex = oid_to_hex(&revs.oid[i]);
+		if (bisect_write(state, hex, terms, 0)) {
+			oid_array_clear(&revs);
+			return BISECT_FAILED;
+		}
+		check_expected_revs(&hex, 1);
+	}
+
+	oid_array_clear(&revs);
+	return bisect_auto_next(terms, NULL);
+}
+
 int cmd_bisect__helper(int argc, const char **argv, const char *prefix)
 {
 	enum {
@@ -847,7 +907,8 @@ int cmd_bisect__helper(int argc, const char **argv, const char *prefix)
 		BISECT_START,
 		BISECT_NEXT,
 		BISECT_AUTO_NEXT,
-		BISECT_AUTOSTART
+		BISECT_AUTOSTART,
+		BISECT_STATE
 	} cmdmode = 0;
 	int no_checkout = 0, res = 0, nolog = 0;
 	struct option options[] = {
@@ -873,6 +934,8 @@ int cmd_bisect__helper(int argc, const char **argv, const char *prefix)
 			 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 BISECT_START is empty or missing"), BISECT_AUTOSTART),
+		OPT_CMDMODE(0, "bisect-state", &cmdmode,
+			 N_("mark the state of ref (or refs)"), BISECT_STATE),
 		OPT_BOOL(0, "no-checkout", &no_checkout,
 			 N_("update BISECT_HEAD instead of checking out the current commit")),
 		OPT_BOOL(0, "no-log", &nolog,
@@ -945,6 +1008,11 @@ int cmd_bisect__helper(int argc, const char **argv, const char *prefix)
 		set_terms(&terms, "bad", "good");
 		res = bisect_autostart(&terms);
 		break;
+	case BISECT_STATE:
+		set_terms(&terms, "bad", "good");
+		get_terms(&terms);
+		res = bisect_state(&terms, argv, argc);
+		break;
 	default:
 		BUG("unknown subcommand %d", (int)cmdmode);
 	}
diff --git a/git-bisect.sh b/git-bisect.sh
index 049ffacdff..2da0810b1a 100755
--- a/git-bisect.sh
+++ b/git-bisect.sh
@@ -39,16 +39,6 @@ _x40="$_x40$_x40$_x40$_x40$_x40$_x40$_x40$_x40"
 TERM_BAD=bad
 TERM_GOOD=good
 
-bisect_head()
-{
-	if test -f "$GIT_DIR/BISECT_HEAD"
-	then
-		echo BISECT_HEAD
-	else
-		echo HEAD
-	fi
-}
-
 bisect_skip() {
 	all=''
 	for arg in "$@"
@@ -61,43 +51,7 @@ bisect_skip() {
 		esac
 		all="$all $revs"
 	done
-	eval bisect_state 'skip' $all
-}
-
-bisect_state() {
-	git bisect--helper --bisect-autostart
-	state=$1
-	git bisect--helper --check-and-set-terms $state $TERM_GOOD $TERM_BAD || exit
-	get_terms
-	case "$#,$state" in
-	0,*)
-		die "Please call 'bisect_state' with at least one argument." ;;
-	1,"$TERM_BAD"|1,"$TERM_GOOD"|1,skip)
-		bisected_head=$(bisect_head)
-		rev=$(git rev-parse --verify "$bisected_head") ||
-			die "$(eval_gettext "Bad rev input: \$bisected_head")"
-		git bisect--helper --bisect-write "$state" "$rev" "$TERM_GOOD" "$TERM_BAD" || exit
-		git bisect--helper --check-expected-revs "$rev" ;;
-	2,"$TERM_BAD"|*,"$TERM_GOOD"|*,skip)
-		shift
-		hash_list=''
-		for rev in "$@"
-		do
-			sha=$(git rev-parse --verify "$rev^{commit}") ||
-				die "$(eval_gettext "Bad rev input: \$rev")"
-			hash_list="$hash_list $sha"
-		done
-		for rev in $hash_list
-		do
-			git bisect--helper --bisect-write "$state" "$rev" "$TERM_GOOD" "$TERM_BAD" || exit
-		done
-		git bisect--helper --check-expected-revs $hash_list ;;
-	*,"$TERM_BAD")
-		die "$(eval_gettext "'git bisect \$TERM_BAD' can take only one argument.")" ;;
-	*)
-		usage ;;
-	esac
-	git bisect--helper --bisect-auto-next
+	eval git bisect--helper --bisect-state 'skip' $all
 }
 
 bisect_visualize() {
@@ -185,8 +139,7 @@ exit code \$res from '\$command' is < 0 or >= 128" >&2
 			state="$TERM_GOOD"
 		fi
 
-		# We have to use a subshell because "bisect_state" can exit.
-		( bisect_state $state >"$GIT_DIR/BISECT_RUN" )
+		git bisect--helper --bisect-state $state >"$GIT_DIR/BISECT_RUN"
 		res=$?
 
 		cat "$GIT_DIR/BISECT_RUN"
@@ -201,7 +154,7 @@ exit code \$res from '\$command' is < 0 or >= 128" >&2
 		if [ $res -ne 0 ]
 		then
 			eval_gettextln "bisect run failed:
-'bisect_state \$state' exited with error code \$res" >&2
+'git bisect--helper --bisect-state \$state' exited with error code \$res" >&2
 			exit $res
 		fi
 
@@ -242,7 +195,7 @@ case "$#" in
 	start)
 		git bisect--helper --bisect-start "$@" ;;
 	bad|good|new|old|"$TERM_BAD"|"$TERM_GOOD")
-		bisect_state "$cmd" "$@" ;;
+		git bisect--helper --bisect-state "$cmd" "$@" ;;
 	skip)
 		bisect_skip "$@" ;;
 	next)

From 6b503aad29509c9829504fea2537d00d43afeb16 Mon Sep 17 00:00:00 2001
From: Pranit Bauva <pranit.bauva@gmail.com>
Date: Thu, 23 Apr 2020 09:07:02 +0200
Subject: [PATCH 10/12] bisect--helper: retire `--check-expected-revs`
 subcommand

The `--check-expected-revs` subcommand is no longer used from the
git-bisect.sh shell script. Instead the function
`check_expected_revs()` is called from the C implementation of
`bisect-next()`.

Mentored-by: Lars Schneider <larsxschneider@gmail.com>
Mentored-by: Christian Couder <chriscool@tuxfamily.org>
Mentored-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: Pranit Bauva <pranit.bauva@gmail.com>
Signed-off-by: Tanushree Tumane <tanushreetumane@gmail.com>
Signed-off-by: Miriam Rubio <mirucam@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 builtin/bisect--helper.c | 6 ------
 1 file changed, 6 deletions(-)

diff --git a/builtin/bisect--helper.c b/builtin/bisect--helper.c
index 9db72f5891..7db58ada6f 100644
--- a/builtin/bisect--helper.c
+++ b/builtin/bisect--helper.c
@@ -898,7 +898,6 @@ int cmd_bisect__helper(int argc, const char **argv, const char *prefix)
 {
 	enum {
 		WRITE_TERMS = 1,
-		CHECK_EXPECTED_REVS,
 		BISECT_RESET,
 		BISECT_WRITE,
 		CHECK_AND_SET_TERMS,
@@ -914,8 +913,6 @@ int cmd_bisect__helper(int argc, const char **argv, const char *prefix)
 	struct option options[] = {
 		OPT_CMDMODE(0, "write-terms", &cmdmode,
 			 N_("write the terms to .git/BISECT_TERMS"), WRITE_TERMS),
-		OPT_CMDMODE(0, "check-expected-revs", &cmdmode,
-			 N_("check for expected revs"), CHECK_EXPECTED_REVS),
 		OPT_CMDMODE(0, "bisect-reset", &cmdmode,
 			 N_("reset the bisection state"), BISECT_RESET),
 		OPT_CMDMODE(0, "bisect-write", &cmdmode,
@@ -956,9 +953,6 @@ int cmd_bisect__helper(int argc, const char **argv, const char *prefix)
 		if (argc != 2)
 			return error(_("--write-terms requires two arguments"));
 		return write_terms(argv[0], argv[1]);
-	case CHECK_EXPECTED_REVS:
-		check_expected_revs(argv, argc);
-		return 0;
 	case BISECT_RESET:
 		if (argc > 1)
 			return error(_("--bisect-reset requires either no argument or a commit"));

From 30c978d6b3adf27b3e6841a736df6e7573ecdad2 Mon Sep 17 00:00:00 2001
From: Pranit Bauva <pranit.bauva@gmail.com>
Date: Thu, 23 Apr 2020 09:07:03 +0200
Subject: [PATCH 11/12] bisect--helper: retire `--write-terms` subcommand

The `--write-terms` subcommand is no longer used from the
git-bisect.sh shell script. Instead the function `write_terms()`
is called from the C implementation of `set_terms()` and
`bisect_start()`.

Mentored-by: Lars Schneider <larsxschneider@gmail.com>
Mentored-by: Christian Couder <chriscool@tuxfamily.org>
Mentored-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: Pranit Bauva <pranit.bauva@gmail.com>
Signed-off-by: Tanushree Tumane <tanushreetumane@gmail.com>
Signed-off-by: Miriam Rubio <mirucam@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 builtin/bisect--helper.c | 10 +---------
 1 file changed, 1 insertion(+), 9 deletions(-)

diff --git a/builtin/bisect--helper.c b/builtin/bisect--helper.c
index 7db58ada6f..e7467dc1c7 100644
--- a/builtin/bisect--helper.c
+++ b/builtin/bisect--helper.c
@@ -20,7 +20,6 @@ static GIT_PATH_FUNC(git_path_head_name, "head-name")
 static GIT_PATH_FUNC(git_path_bisect_names, "BISECT_NAMES")
 
 static const char * const git_bisect_helper_usage[] = {
-	N_("git bisect--helper --write-terms <bad_term> <good_term>"),
 	N_("git bisect--helper --bisect-reset [<commit>]"),
 	N_("git bisect--helper --bisect-write [--no-log] <state> <revision> <good_term> <bad_term>"),
 	N_("git bisect--helper --bisect-check-and-set-terms <command> <good_term> <bad_term>"),
@@ -897,8 +896,7 @@ static enum bisect_error bisect_state(struct bisect_terms *terms, const char **a
 int cmd_bisect__helper(int argc, const char **argv, const char *prefix)
 {
 	enum {
-		WRITE_TERMS = 1,
-		BISECT_RESET,
+		BISECT_RESET = 1,
 		BISECT_WRITE,
 		CHECK_AND_SET_TERMS,
 		BISECT_NEXT_CHECK,
@@ -911,8 +909,6 @@ int cmd_bisect__helper(int argc, const char **argv, const char *prefix)
 	} cmdmode = 0;
 	int no_checkout = 0, res = 0, nolog = 0;
 	struct option options[] = {
-		OPT_CMDMODE(0, "write-terms", &cmdmode,
-			 N_("write the terms to .git/BISECT_TERMS"), WRITE_TERMS),
 		OPT_CMDMODE(0, "bisect-reset", &cmdmode,
 			 N_("reset the bisection state"), BISECT_RESET),
 		OPT_CMDMODE(0, "bisect-write", &cmdmode,
@@ -949,10 +945,6 @@ int cmd_bisect__helper(int argc, const char **argv, const char *prefix)
 		usage_with_options(git_bisect_helper_usage, options);
 
 	switch (cmdmode) {
-	case WRITE_TERMS:
-		if (argc != 2)
-			return error(_("--write-terms requires two arguments"));
-		return write_terms(argv[0], argv[1]);
 	case BISECT_RESET:
 		if (argc > 1)
 			return error(_("--bisect-reset requires either no argument or a commit"));

From 011eca7cfdb7f13ee285c00dfe9ea576ec1166a7 Mon Sep 17 00:00:00 2001
From: Pranit Bauva <pranit.bauva@gmail.com>
Date: Thu, 23 Apr 2020 09:07:04 +0200
Subject: [PATCH 12/12] bisect--helper: retire `--bisect-autostart` subcommand

The `--bisect-autostart` subcommand is no longer used from the
git-bisect.sh shell script. Instead the function
`bisect_autostart()` is directly called from the C implementation.

Mentored-by: Lars Schneider <larsxschneider@gmail.com>
Mentored-by: Christian Couder <chriscool@tuxfamily.org>
Mentored-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: Pranit Bauva <pranit.bauva@gmail.com>
Signed-off-by: Tanushree Tumane <tanushreetumane@gmail.com>
Signed-off-by: Miriam Rubio <mirucam@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 builtin/bisect--helper.c | 10 ----------
 1 file changed, 10 deletions(-)

diff --git a/builtin/bisect--helper.c b/builtin/bisect--helper.c
index e7467dc1c7..66f9b8eab6 100644
--- a/builtin/bisect--helper.c
+++ b/builtin/bisect--helper.c
@@ -29,7 +29,6 @@ static const char * const git_bisect_helper_usage[] = {
 					     "[--no-checkout] [<bad> [<good>...]] [--] [<paths>...]"),
 	N_("git bisect--helper --bisect-next"),
 	N_("git bisect--helper --bisect-auto-next"),
-	N_("git bisect--helper --bisect-autostart"),
 	N_("git bisect--helper --bisect-state (bad|new) [<rev>]"),
 	N_("git bisect--helper --bisect-state (good|old) [<rev>...]"),
 	NULL
@@ -904,7 +903,6 @@ int cmd_bisect__helper(int argc, const char **argv, const char *prefix)
 		BISECT_START,
 		BISECT_NEXT,
 		BISECT_AUTO_NEXT,
-		BISECT_AUTOSTART,
 		BISECT_STATE
 	} cmdmode = 0;
 	int no_checkout = 0, res = 0, nolog = 0;
@@ -925,8 +923,6 @@ int cmd_bisect__helper(int argc, const char **argv, const char *prefix)
 			 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 BISECT_START is empty or missing"), BISECT_AUTOSTART),
 		OPT_CMDMODE(0, "bisect-state", &cmdmode,
 			 N_("mark the state of ref (or refs)"), BISECT_STATE),
 		OPT_BOOL(0, "no-checkout", &no_checkout,
@@ -988,12 +984,6 @@ int cmd_bisect__helper(int argc, const char **argv, const char *prefix)
 		get_terms(&terms);
 		res = bisect_auto_next(&terms, prefix);
 		break;
-	case BISECT_AUTOSTART:
-		if (argc)
-			return error(_("--bisect-autostart requires 0 arguments"));
-		set_terms(&terms, "bad", "good");
-		res = bisect_autostart(&terms);
-		break;
 	case BISECT_STATE:
 		set_terms(&terms, "bad", "good");
 		get_terms(&terms);