[PATCH v10 0/7]Finish converting git bisect to C part 2 subset 2

[PATCH v10 0/7]Finish converting git bisect to C part 2 subset 2

[Miriam Rubio]

These patches correspond to a second part of patch series 
of Outreachy project "Finish converting `git bisect` from shell to C" 
started by Pranit Bauva and Tanushree Tumane
(https://public-inbox.org/git/pull.117.git.gitgitgadget@gmail.com) and
continued by me.

This patch series version is composed by the last seven patches of part2
set. 

These patch series emails were generated from:
https://gitlab.com/mirucam/git/commits/git-bisect-work-part2-v10-subset2.

I would like to thank Johannes Schindelin for reviewing this patch series
and to Christian Couder for his advice and help.


General information
-------------------

* Rebased on d4a392452e (Git 2.29-rc1, 2020-10-08) to build with latest
changes in bisect--helper.c file.

Specific changes
----------------

[1/7]bisect--helper: finish porting `bisect_start()` to C

* Add comment in commit message related with `eval` command.
* Remove code comment that does not apply anymore.

---

[4/7]bisect--helper: reimplement `bisect_state` & `bisect_head` shell
    functions in C
    
* Add comment in commit message related with `eval` command.
* Change some code to convert shell command more faithfully.
* Add call to bisect_autostart() in bisect_state().
* Amend error message.
    
---


Pranit Bauva (7):
  bisect--helper: finish porting `bisect_start()` to C
  bisect--helper: retire `--bisect-clean-state` subcommand
  bisect--helper: retire `--next-all` subcommand
  bisect--helper: reimplement `bisect_state` & `bisect_head` shell
    functions in C
  bisect--helper: retire `--check-expected-revs` subcommand
  bisect--helper: retire `--write-terms` subcommand
  bisect--helper: retire `--bisect-autostart` subcommand

 builtin/bisect--helper.c | 185 +++++++++++++++++++++++----------------
 git-bisect.sh            |  81 ++---------------
 2 files changed, 115 insertions(+), 151 deletions(-)

-- 
2.25.0

[PATCH v10 1/7] bisect--helper: finish porting `bisect_start()` to C

[Miriam Rubio]

From: Pranit Bauva <pranit.bauva@gmail.com>

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()`.

Note that the `eval` in the changed line of `git-bisect.sh` cannot be
dropped: it is necessary because the `rev` and the `tail`
variables may contain multiple, quoted arguments that need to be
passed to `bisect--helper` (without the quotes, naturally).

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>
---
 builtin/bisect--helper.c | 41 ++++++++++++++++++++++++++--------------
 git-bisect.sh            | 26 ++-----------------------
 2 files changed, 29 insertions(+), 38 deletions(-)

diff --git a/builtin/bisect--helper.c b/builtin/bisect--helper.c
index 7512b880f0..8adad68268 100644
--- a/builtin/bisect--helper.c
+++ b/builtin/bisect--helper.c
@@ -85,6 +85,19 @@ static int one_of(const char *term, ...)
 	return res;
 }
 
+/*
+ * return code BISECT_INTERNAL_SUCCESS_MERGE_BASE
+ * and BISECT_INTERNAL_SUCCESS_1ST_BAD_FOUND are codes
+ * that indicate special success.
+ */
+
+static int is_bisect_success(enum bisect_error res)
+{
+	return !res ||
+		res == BISECT_INTERNAL_SUCCESS_1ST_BAD_FOUND ||
+		res == BISECT_INTERNAL_SUCCESS_MERGE_BASE;
+}
+
 static int write_in_file(const char *path, const char *mode, const char *format, va_list args)
 {
 	FILE *fp = NULL;
@@ -609,12 +622,13 @@ 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, const char **argv, int argc)
+static enum bisect_error 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, 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;
@@ -753,14 +767,7 @@ static int bisect_start(struct bisect_terms *terms, const char **argv, int argc)
 	 * Get rid of any old bisect state.
 	 */
 	if (bisect_clean_state())
-		return -1;
-
-	/*
-	 * 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".
-	 */
+		return BISECT_FAILED;
 
 	/*
 	 * Write new start state
@@ -777,7 +784,7 @@ static int bisect_start(struct bisect_terms *terms, const char **argv, int argc)
 		}
 		if (update_ref(NULL, "BISECT_HEAD", &oid, NULL, 0,
 			       UPDATE_REFS_MSG_ON_ERR)) {
-			res = -1;
+			res = BISECT_FAILED;
 			goto finish;
 		}
 	}
@@ -789,25 +796,31 @@ static int bisect_start(struct bisect_terms *terms, const char **argv, int argc)
 	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);
+	if (!is_bisect_success(res))
+		bisect_clean_state();
 	return res;
 }
 
diff --git a/git-bisect.sh b/git-bisect.sh
index ea7e684ebb..dda386bc3a 100755
--- a/git-bisect.sh
+++ b/git-bisect.sh
@@ -49,27 +49,6 @@ bisect_head()
 	fi
 }
 
-bisect_start() {
-	git bisect--helper --bisect-start $@ || exit
-
-	#
-	# Change state.
-	# In case of mistaken revs or checkout error, or signals received,
-	# "bisect_auto_next" below may exit or misbehave.
-	# We have to trap this to be able to clean up using
-	# "bisect_clean_state".
-	#
-	trap 'git bisect--helper --bisect-clean-state' 0
-	trap 'exit 255' 1 2 3 15
-
-	#
-	# Check if we can proceed to the next bisect state.
-	#
-	git bisect--helper --bisect-auto-next || exit
-
-	trap '-' 0
-}
-
 bisect_skip() {
 	all=''
 	for arg in "$@"
@@ -163,8 +142,7 @@ bisect_replay () {
 		get_terms
 		case "$command" in
 		start)
-			cmd="bisect_start $rev $tail"
-			eval "$cmd" ;;
+			eval "git bisect--helper --bisect-start $rev $tail" ;;
 		"$TERM_GOOD"|"$TERM_BAD"|skip)
 			git bisect--helper --bisect-write "$command" "$rev" "$TERM_GOOD" "$TERM_BAD" || exit;;
 		terms)
@@ -264,7 +242,7 @@ case "$#" 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)
-- 
2.25.0

[PATCH v10 2/7] bisect--helper: retire `--bisect-clean-state` subcommand

[Miriam Rubio]

From: Pranit Bauva <pranit.bauva@gmail.com>

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>
---
 builtin/bisect--helper.c | 8 --------
 1 file changed, 8 deletions(-)

diff --git a/builtin/bisect--helper.c b/builtin/bisect--helper.c
index 8adad68268..fbb9046737 100644
--- a/builtin/bisect--helper.c
+++ b/builtin/bisect--helper.c
@@ -22,7 +22,6 @@ 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"),
 	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>"),
@@ -861,7 +860,6 @@ 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,
@@ -879,8 +877,6 @@ 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,
@@ -922,10 +918,6 @@ 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;
-- 
2.25.0

[PATCH v10 3/7] bisect--helper: retire `--next-all` subcommand

[Miriam Rubio]

From: Pranit Bauva <pranit.bauva@gmail.com>

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>
---
 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 fbb9046737..f1a7cfbfaf 100644
--- a/builtin/bisect--helper.c
+++ b/builtin/bisect--helper.c
@@ -20,7 +20,6 @@ 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"),
 	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>"),
@@ -858,8 +857,7 @@ 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,
@@ -873,8 +871,6 @@ int cmd_bisect__helper(int argc, const char **argv, const char *prefix)
 	} cmdmode = 0;
 	int 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,
@@ -911,9 +907,6 @@ 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);
-		break;
 	case WRITE_TERMS:
 		if (argc != 2)
 			return error(_("--write-terms requires two arguments"));
-- 
2.25.0

[PATCH v10 4/7] bisect--helper: reimplement `bisect_state` & `bisect_head` shell functions in C

[Miriam Rubio]

From: Pranit Bauva <pranit.bauva@gmail.com>

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.

Note that the `eval` in the changed line of `git-bisect.sh` cannot be
dropped: it is necessary because the `rev` and the `tail`
variables may contain multiple, quoted arguments that need to be
passed to `bisect--helper` (without the quotes, naturally).

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>
---
 builtin/bisect--helper.c | 84 +++++++++++++++++++++++++++++++++++++++-
 git-bisect.sh            | 55 ++------------------------
 2 files changed, 87 insertions(+), 52 deletions(-)

diff --git a/builtin/bisect--helper.c b/builtin/bisect--helper.c
index f1a7cfbfaf..66b5346e42 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
 };
 
@@ -854,6 +856,78 @@ static int bisect_autostart(struct bisect_terms *terms)
 	return res;
 }
 
+static enum bisect_error bisect_state(struct bisect_terms *terms, const char **argv,
+				      int argc)
+{
+	const char *state;
+	int i, verify_expected = 1;
+	struct object_id oid, expected;
+	struct strbuf buf = STRBUF_INIT;
+	struct oid_array revs = OID_ARRAY_INIT;
+
+	if (!argc)
+		return error(_("Please call `--bisect-state` with at least one argument"));
+
+	if (bisect_autostart(terms))
+		return BISECT_FAILED;
+
+	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 (argc > 1 && !strcmp(state, terms->term_bad))
+		return error(_("'git bisect %s' can take only one argument."), terms->term_bad);
+
+	if (argc == 0) {
+		const char *head = "BISECT_HEAD";
+		enum get_oid_result res_head = get_oid(head, &oid);
+
+		if (res_head == MISSING_OBJECT) {
+			head = "HEAD";
+			res_head = get_oid(head, &oid);
+		}
+
+		if (res_head)
+			error(_("Bad rev input: %s"), head);
+		oid_array_append(&revs, &oid);
+	}
+
+	/*
+	 * All input revs must be checked before executing bisect_write()
+	 * to discard junk revs.
+	 */
+
+	for (; argc; argc--, argv++) {
+		if (get_oid(*argv, &oid)){
+			error(_("Bad rev input: %s"), *argv);
+			return BISECT_FAILED;
+		}
+		oid_array_append(&revs, &oid);
+	}
+
+	if (strbuf_read_file(&buf, git_path_bisect_expected_rev(), 0) < the_hash_algo->hexsz ||
+	    get_oid_hex(buf.buf, &expected) < 0)
+		verify_expected = 0; /* Ignore invalid file contents */
+	strbuf_release(&buf);
+
+	for (i = 0; i < revs.nr; i++) {
+		if (bisect_write(state, oid_to_hex(&revs.oid[i]), terms, 0))
+			return BISECT_FAILED;
+
+		if (verify_expected && !oideq(&revs.oid[i], &expected)) {
+			unlink_or_warn(git_path_bisect_ancestors_ok());
+			unlink_or_warn(git_path_bisect_expected_rev());
+			verify_expected = 0;
+		}
+	}
+
+	oid_array_clear(&revs);
+	return bisect_auto_next(terms, NULL);
+}
+
 int cmd_bisect__helper(int argc, const char **argv, const char *prefix)
 {
 	enum {
@@ -867,7 +941,8 @@ int cmd_bisect__helper(int argc, const char **argv, const char *prefix)
 		BISECT_START,
 		BISECT_AUTOSTART,
 		BISECT_NEXT,
-		BISECT_AUTO_NEXT
+		BISECT_AUTO_NEXT,
+		BISECT_STATE
 	} cmdmode = 0;
 	int res = 0, nolog = 0;
 	struct option options[] = {
@@ -893,6 +968,8 @@ 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 it has not yet been started"), BISECT_AUTOSTART),
+		OPT_CMDMODE(0, "bisect-state", &cmdmode,
+			 N_("mark the state of ref (or refs)"), BISECT_STATE),
 		OPT_BOOL(0, "no-log", &nolog,
 			 N_("no log for BISECT_WRITE")),
 		OPT_END()
@@ -963,6 +1040,11 @@ 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", cmdmode);
 	}
diff --git a/git-bisect.sh b/git-bisect.sh
index dda386bc3a..1f3f6e9fc5 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 git rev-parse --verify -q BISECT_HEAD > /dev/null
-	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 || exit
-	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() {
@@ -187,8 +141,7 @@ 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"
@@ -203,7 +156,7 @@ 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
+'bisect-state \$state' exited with error code \$res" >&2
 			exit $res
 		fi
 
@@ -244,7 +197,7 @@ 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)
-- 
2.25.0

Re: [PATCH v10 4/7] bisect--helper: reimplement `bisect_state` & `bisect_head` shell functions in C

[Johannes Schindelin]

Hi Miriam,

I read through the entire patch series, and have only _tiny_ nitpicks
left. Well done!

On Sat, 10 Oct 2020, Miriam Rubio wrote:

> diff --git a/builtin/bisect--helper.c b/builtin/bisect--helper.c
> index f1a7cfbfaf..66b5346e42 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
>  };
>
> @@ -854,6 +856,78 @@ static int bisect_autostart(struct bisect_terms *terms)
>  	return res;
>  }
>
> +static enum bisect_error bisect_state(struct bisect_terms *terms, const char **argv,
> +				      int argc)
> +{
> +	const char *state;
> +	int i, verify_expected = 1;
> +	struct object_id oid, expected;
> +	struct strbuf buf = STRBUF_INIT;
> +	struct oid_array revs = OID_ARRAY_INIT;
> +
> +	if (!argc)
> +		return error(_("Please call `--bisect-state` with at least one argument"));
> +
> +	if (bisect_autostart(terms))
> +		return BISECT_FAILED;
> +
> +	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 (argc > 1 && !strcmp(state, terms->term_bad))
> +		return error(_("'git bisect %s' can take only one argument."), terms->term_bad);
> +
> +	if (argc == 0) {
> +		const char *head = "BISECT_HEAD";
> +		enum get_oid_result res_head = get_oid(head, &oid);
> +
> +		if (res_head == MISSING_OBJECT) {
> +			head = "HEAD";
> +			res_head = get_oid(head, &oid);
> +		}
> +
> +		if (res_head)
> +			error(_("Bad rev input: %s"), head);
> +		oid_array_append(&revs, &oid);
> +	}
> +
> +	/*
> +	 * All input revs must be checked before executing bisect_write()
> +	 * to discard junk revs.
> +	 */
> +
> +	for (; argc; argc--, argv++) {
> +		if (get_oid(*argv, &oid)){
> +			error(_("Bad rev input: %s"), *argv);

Here, we leak `revs`. Maybe

			oid_array_clear(&revs);

?

> +			return BISECT_FAILED;
> +		}
> +		oid_array_append(&revs, &oid);
> +	}
> +
> +	if (strbuf_read_file(&buf, git_path_bisect_expected_rev(), 0) < the_hash_algo->hexsz ||
> +	    get_oid_hex(buf.buf, &expected) < 0)
> +		verify_expected = 0; /* Ignore invalid file contents */
> +	strbuf_release(&buf);
> +
> +	for (i = 0; i < revs.nr; i++) {
> +		if (bisect_write(state, oid_to_hex(&revs.oid[i]), terms, 0))

Same here.

It is not exactly clear to me how problematic this leak would be, as we're
only calling this function from `cmd_*()` and return immediately
afterwards. It might be worth cleaning up memory, though, in case we want
to move this code into `libgit.a` and potentially call it from elsewhere
(where we would _not_ necessarily `exit()` immediately upon seeing a
failure).

Otherwise, the patch series looks good to me!

Thank you for your patient efforts,
Dscho

> +			return BISECT_FAILED;
> +
> +		if (verify_expected && !oideq(&revs.oid[i], &expected)) {
> +			unlink_or_warn(git_path_bisect_ancestors_ok());
> +			unlink_or_warn(git_path_bisect_expected_rev());
> +			verify_expected = 0;
> +		}
> +	}
> +
> +	oid_array_clear(&revs);
> +	return bisect_auto_next(terms, NULL);
> +}
> +
>  int cmd_bisect__helper(int argc, const char **argv, const char *prefix)
>  {
>  	enum {
> @@ -867,7 +941,8 @@ int cmd_bisect__helper(int argc, const char **argv, const char *prefix)
>  		BISECT_START,
>  		BISECT_AUTOSTART,
>  		BISECT_NEXT,
> -		BISECT_AUTO_NEXT
> +		BISECT_AUTO_NEXT,
> +		BISECT_STATE
>  	} cmdmode = 0;
>  	int res = 0, nolog = 0;
>  	struct option options[] = {
> @@ -893,6 +968,8 @@ 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 it has not yet been started"), BISECT_AUTOSTART),
> +		OPT_CMDMODE(0, "bisect-state", &cmdmode,
> +			 N_("mark the state of ref (or refs)"), BISECT_STATE),
>  		OPT_BOOL(0, "no-log", &nolog,
>  			 N_("no log for BISECT_WRITE")),
>  		OPT_END()
> @@ -963,6 +1040,11 @@ 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", cmdmode);
>  	}
> diff --git a/git-bisect.sh b/git-bisect.sh
> index dda386bc3a..1f3f6e9fc5 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 git rev-parse --verify -q BISECT_HEAD > /dev/null
> -	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 || exit
> -	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' $all
>  }
>
>  bisect_visualize() {
> @@ -187,8 +141,7 @@ exit code \$res from '\$command' is < 0 or >= 128" >&2
>  			state="$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"
> @@ -203,7 +156,7 @@ 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
> +'bisect-state \$state' exited with error code \$res" >&2
>  			exit $res
>  		fi
>
> @@ -244,7 +197,7 @@ case "$#" 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)
> --
> 2.25.0
>
>

[PATCH v10 5/7] bisect--helper: retire `--check-expected-revs` subcommand

[Miriam Rubio]

From: Pranit Bauva <pranit.bauva@gmail.com>

The `--check-expected-revs` subcommand is no longer used from the
git-bisect.sh shell script. Functions `check_expected_revs` and
`is_expected_revs` are also deleted.

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>
---
 builtin/bisect--helper.c | 30 ------------------------------
 1 file changed, 30 deletions(-)

diff --git a/builtin/bisect--helper.c b/builtin/bisect--helper.c
index 66b5346e42..14a8f2b9df 100644
--- a/builtin/bisect--helper.c
+++ b/builtin/bisect--helper.c
@@ -187,30 +187,6 @@ static int write_terms(const char *bad, const char *good)
 	return res;
 }
 
-static int is_expected_rev(const char *expected_hex)
-{
-	struct strbuf actual_hex = STRBUF_INIT;
-	int res = 0;
-	if (strbuf_read_file(&actual_hex, git_path_bisect_expected_rev(), 0) >= 40) {
-		strbuf_trim(&actual_hex);
-		res = !strcmp(actual_hex.buf, expected_hex);
-	}
-	strbuf_release(&actual_hex);
-	return res;
-}
-
-static void check_expected_revs(const char **revs, int rev_nr)
-{
-	int i;
-
-	for (i = 0; i < rev_nr; i++) {
-		if (!is_expected_rev(revs[i])) {
-			unlink_or_warn(git_path_bisect_ancestors_ok());
-			unlink_or_warn(git_path_bisect_expected_rev());
-		}
-	}
-}
-
 static int bisect_reset(const char *commit)
 {
 	struct strbuf branch = STRBUF_INIT;
@@ -932,7 +908,6 @@ 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,
@@ -948,8 +923,6 @@ 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,
@@ -988,9 +961,6 @@ 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"));
-- 
2.25.0

[PATCH v10 6/7] bisect--helper: retire `--write-terms` subcommand

[Miriam Rubio]

From: Pranit Bauva <pranit.bauva@gmail.com>

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>
---
 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 14a8f2b9df..f90b3efdd1 100644
--- a/builtin/bisect--helper.c
+++ b/builtin/bisect--helper.c
@@ -20,7 +20,6 @@ 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 --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>"),
@@ -907,8 +906,7 @@ 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,
@@ -921,8 +919,6 @@ int cmd_bisect__helper(int argc, const char **argv, const char *prefix)
 	} cmdmode = 0;
 	int 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,
@@ -957,10 +953,6 @@ 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"));
-- 
2.25.0

[PATCH v10 7/7] bisect--helper: retire `--bisect-autostart` subcommand

[Miriam Rubio]

From: Pranit Bauva <pranit.bauva@gmail.com>

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>
---
 builtin/bisect--helper.c | 9 ---------
 1 file changed, 9 deletions(-)

diff --git a/builtin/bisect--helper.c b/builtin/bisect--helper.c
index f90b3efdd1..ee65f97079 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] [--first-parent] [<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
@@ -935,8 +934,6 @@ 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 it has not yet been started"), BISECT_AUTOSTART),
 		OPT_CMDMODE(0, "bisect-state", &cmdmode,
 			 N_("mark the state of ref (or refs)"), BISECT_STATE),
 		OPT_BOOL(0, "no-log", &nolog,
@@ -996,12 +993,6 @@ 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 does not accept arguments"));
-		set_terms(&terms, "bad", "good");
-		res = bisect_autostart(&terms);
-		break;
 	case BISECT_STATE:
 		set_terms(&terms, "bad", "good");
 		get_terms(&terms);
-- 
2.25.0