[PATCH v2 1/7] bisect : correction of typo

[PATCH v2 1/7] bisect : correction of typo

[Antoine Delaite]

Signed-off-by: Antoine Delaite <antoine.delaite@ensimag.grenoble-inp.fr>
---
 bisect.c                    |    2 +-
 t/t6030-bisect-porcelain.sh |    2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/bisect.c b/bisect.c
index 10f5e57..de92953 100644
--- a/bisect.c
+++ b/bisect.c
@@ -743,7 +743,7 @@ static void handle_bad_merge_base(void)
 
 	fprintf(stderr, "Some good revs are not ancestor of the bad rev.\n"
 		"git bisect cannot work properly in this case.\n"
-		"Maybe you mistake good and bad revs?\n");
+		"Maybe you mistook good and bad revs?\n");
 	exit(1);
 }
 
diff --git a/t/t6030-bisect-porcelain.sh b/t/t6030-bisect-porcelain.sh
index 06b4868..9e2c203 100755
--- a/t/t6030-bisect-porcelain.sh
+++ b/t/t6030-bisect-porcelain.sh
@@ -362,7 +362,7 @@ test_expect_success 'bisect starting with a detached HEAD' '
 test_expect_success 'bisect errors out if bad and good are mistaken' '
 	git bisect reset &&
 	test_must_fail git bisect start $HASH2 $HASH4 2> rev_list_error &&
-	grep "mistake good and bad" rev_list_error &&
+	grep "mistook good and bad" rev_list_error &&
 	git bisect reset
 '
 
-- 
1.7.1

[PATCH v2 2/7] bisect: replace hardcoded "bad|good" by variables

[Antoine Delaite]

To add new tags like old/new and have keywords less confusing, the
first step is to avoid hardcoding the keywords.

The default mode is still bad/good.

Signed-off-by: Antoine Delaite <antoine.delaite@ensimag.grenoble-inp.fr>
Signed-off-by: Louis Stuber <stuberl@ensimag.grenoble-inp.fr>
Signed-off-by: Valentin Duperray <Valentin.Duperray@ensimag.imag.fr>
Signed-off-by: Franck Jonas <Franck.Jonas@ensimag.imag.fr>
Signed-off-by: Lucien Kong <Lucien.Kong@ensimag.imag.fr>
Signed-off-by: Thomas Nguy <Thomas.Nguy@ensimag.imag.fr>
Signed-off-by: Huynh Khoi Nguyen Nguyen <Huynh-Khoi-Nguyen.Nguyen@ensimag.imag.fr>
Signed-off-by: Matthieu Moy <Matthieu.Moy@grenoble-inp.fr>
---
 bisect.c      |   49 ++++++++++++++++++++++++++++++++-----------------
 git-bisect.sh |   57 +++++++++++++++++++++++++++++++--------------------------
 2 files changed, 63 insertions(+), 43 deletions(-)
 mode change 100755 => 100644 git-bisect.sh

diff --git a/bisect.c b/bisect.c
index de92953..eb2f555 100644
--- a/bisect.c
+++ b/bisect.c
@@ -21,6 +21,9 @@ static const char *argv_checkout[] = {"checkout", "-q", NULL, "--", NULL};
 static const char *argv_show_branch[] = {"show-branch", NULL, NULL};
 static const char *argv_update_ref[] = {"update-ref", "--no-deref", "BISECT_HEAD", NULL, NULL};
 
+static const char *name_bad;
+static const char *name_good;
+
 /* Remember to update object flag allocation in object.h */
 #define COUNTED		(1u<<16)
 
@@ -403,10 +406,14 @@ struct commit_list *find_bisection(struct commit_list *list,
 static int register_ref(const char *refname, const unsigned char *sha1,
 			int flags, void *cb_data)
 {
-	if (!strcmp(refname, "bad")) {
+	char good_prefix[256];
+	strcpy(good_prefix, name_good);
+	strcat(good_prefix, "-");
+
+	if (!strcmp(refname, name_bad)) {
 		current_bad_oid = xmalloc(sizeof(*current_bad_oid));
 		hashcpy(current_bad_oid->hash, sha1);
-	} else if (starts_with(refname, "good-")) {
+	} else if (starts_with(refname, good_prefix)) {
 		sha1_array_append(&good_revs, sha1);
 	} else if (starts_with(refname, "skip-")) {
 		sha1_array_append(&skipped_revs, sha1);
@@ -634,7 +641,7 @@ static void exit_if_skipped_commits(struct commit_list *tried,
 		return;
 
 	printf("There are only 'skip'ped commits left to test.\n"
-	       "The first bad commit could be any of:\n");
+	       "The first %s commit could be any of:\n", name_bad);
 	print_commit_list(tried, "%s\n", "%s\n");
 	if (bad)
 		printf("%s\n", oid_to_hex(bad));
@@ -732,18 +739,21 @@ static void handle_bad_merge_base(void)
 	if (is_expected_rev(current_bad_oid)) {
 		char *bad_hex = oid_to_hex(current_bad_oid);
 		char *good_hex = join_sha1_array_hex(&good_revs, ' ');
-
-		fprintf(stderr, "The merge base %s is bad.\n"
-			"This means the bug has been fixed "
-			"between %s and [%s].\n",
-			bad_hex, bad_hex, good_hex);
-
+		if (!strcmp(name_bad, "bad")) {
+			fprintf(stderr, "The merge base %s is bad.\n"
+				"This means the bug has been fixed "
+				"between %s and [%s].\n",
+				bad_hex, bad_hex, good_hex);
+		} else {
+			die("BUG: terms %s/%s not managed", name_bad, name_good);
+		}
 		exit(3);
 	}
 
-	fprintf(stderr, "Some good revs are not ancestor of the bad rev.\n"
+	fprintf(stderr, "Some %s revs are not ancestor of the %s rev.\n"
 		"git bisect cannot work properly in this case.\n"
-		"Maybe you mistook good and bad revs?\n");
+		"Maybe you mistook %s and %s revs?\n",
+		name_good, name_bad, name_good, name_bad);
 	exit(1);
 }
 
@@ -755,10 +765,10 @@ static void handle_skipped_merge_base(const unsigned char *mb)
 
 	warning("the merge base between %s and [%s] "
 		"must be skipped.\n"
-		"So we cannot be sure the first bad commit is "
+		"So we cannot be sure the first %s commit is "
 		"between %s and %s.\n"
 		"We continue anyway.",
-		bad_hex, good_hex, mb_hex, bad_hex);
+		bad_hex, good_hex, name_bad, mb_hex, bad_hex);
 	free(good_hex);
 }
 
@@ -839,7 +849,7 @@ static void check_good_are_ancestors_of_bad(const char *prefix, int no_checkout)
 	int fd;
 
 	if (!current_bad_oid)
-		die("a bad revision is needed");
+		die("a %s revision is needed", name_bad);
 
 	/* Check if file BISECT_ANCESTORS_OK exists. */
 	if (!stat(filename, &st) && S_ISREG(st.st_mode))
@@ -905,6 +915,8 @@ int bisect_next_all(const char *prefix, int no_checkout)
 	const unsigned char *bisect_rev;
 	char bisect_rev_hex[GIT_SHA1_HEXSZ + 1];
 
+	name_bad="bad";
+	name_good="good";
 	if (read_bisect_refs())
 		die("reading bisect refs failed");
 
@@ -926,8 +938,10 @@ int bisect_next_all(const char *prefix, int no_checkout)
 		 */
 		exit_if_skipped_commits(tried, NULL);
 
-		printf("%s was both good and bad\n",
-		       oid_to_hex(current_bad_oid));
+		printf("%s was both %s and %s\n",
+		       oid_to_hex(current_bad_oid),
+		       name_good,
+		       name_bad);
 		exit(1);
 	}
 
@@ -942,7 +956,8 @@ int bisect_next_all(const char *prefix, int no_checkout)
 
 	if (!hashcmp(bisect_rev, current_bad_oid->hash)) {
 		exit_if_skipped_commits(tried, current_bad_oid);
-		printf("%s is the first bad commit\n", bisect_rev_hex);
+		printf("%s is the first %s commit\n", bisect_rev_hex,
+			name_bad);
 		show_diff_tree(prefix, revs.commits->item);
 		/* This means the bisection process succeeded. */
 		exit(10);
diff --git a/git-bisect.sh b/git-bisect.sh
old mode 100755
new mode 100644
index ae3fec2..ce6412f
--- a/git-bisect.sh
+++ b/git-bisect.sh
@@ -32,6 +32,8 @@ OPTIONS_SPEC=
 
 _x40='[0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f]'
 _x40="$_x40$_x40$_x40$_x40$_x40$_x40$_x40$_x40"
+NAME_BAD=bad
+NAME_GOOD=good
 
 bisect_head()
 {
@@ -100,8 +102,8 @@ bisect_start() {
 				break
 			}
 			case $bad_seen in
-			0) state='bad' ; bad_seen=1 ;;
-			*) state='good' ;;
+			0) state=$NAME_BAD ; bad_seen=1 ;;
+			*) state=$NAME_GOOD ;;
 			esac
 			eval="$eval bisect_write '$state' '$rev' 'nolog' &&"
 			shift
@@ -184,9 +186,12 @@ bisect_write() {
 	rev="$2"
 	nolog="$3"
 	case "$state" in
-		bad)		tag="$state" ;;
-		good|skip)	tag="$state"-"$rev" ;;
-		*)		die "$(eval_gettext "Bad bisect_write argument: \$state")" ;;
+		"$NAME_BAD")
+			tag="$state" ;;
+		"$NAME_GOOD"|skip)
+			tag="$state"-"$rev" ;;
+		*)
+			die "$(eval_gettext "Bad bisect_write argument: \$state")" ;;
 	esac
 	git update-ref "refs/bisect/$tag" "$rev" || exit
 	echo "# $state: $(git show-branch $rev)" >>"$GIT_DIR/BISECT_LOG"
@@ -230,12 +235,12 @@ bisect_state() {
 	case "$#,$state" in
 	0,*)
 		die "$(gettext "Please call 'bisect_state' with at least one argument.")" ;;
-	1,bad|1,good|1,skip)
+	1,"$NAME_BAD"|1,"$NAME_GOOD"|1,skip)
 		rev=$(git rev-parse --verify $(bisect_head)) ||
 			die "$(gettext "Bad rev input: $(bisect_head)")"
 		bisect_write "$state" "$rev"
 		check_expected_revs "$rev" ;;
-	2,bad|*,good|*,skip)
+	2,"$NAME_BAD"|*,"$NAME_GOOD"|*,skip)
 		shift
 		hash_list=''
 		for rev in "$@"
@@ -249,8 +254,8 @@ bisect_state() {
 			bisect_write "$state" "$rev"
 		done
 		check_expected_revs $hash_list ;;
-	*,bad)
-		die "$(gettext "'git bisect bad' can take only one argument.")" ;;
+	*,"$NAME_BAD")
+		die "$(eval_gettext "'git bisect \$NAME_BAD' can take only one argument.")" ;;
 	*)
 		usage ;;
 	esac
@@ -259,21 +264,21 @@ bisect_state() {
 
 bisect_next_check() {
 	missing_good= missing_bad=
-	git show-ref -q --verify refs/bisect/bad || missing_bad=t
-	test -n "$(git for-each-ref "refs/bisect/good-*")" || missing_good=t
+	git show-ref -q --verify refs/bisect/$NAME_BAD || missing_bad=t
+	test -n "$(git for-each-ref "refs/bisect/$NAME_GOOD-*")" || missing_good=t
 
 	case "$missing_good,$missing_bad,$1" in
 	,,*)
-		: have both good and bad - ok
+		: have both $NAME_GOOD and $NAME_BAD - ok
 		;;
 	*,)
 		# do not have both but not asked to fail - just report.
 		false
 		;;
-	t,,good)
+	t,,"$NAME_GOOD")
 		# have bad but not good.  we could bisect although
 		# this is less optimum.
-		gettextln "Warning: bisecting only with a bad commit." >&2
+		eval_gettextln "Warning: bisecting only with a \$NAME_BAD commit." >&2
 		if test -t 0
 		then
 			# TRANSLATORS: Make sure to include [Y] and [n] in your
@@ -283,7 +288,7 @@ bisect_next_check() {
 			read yesno
 			case "$yesno" in [Nn]*) exit 1 ;; esac
 		fi
-		: bisect without good...
+		: bisect without $NAME_GOOD...
 		;;
 	*)
 
@@ -307,7 +312,7 @@ bisect_auto_next() {
 bisect_next() {
 	case "$#" in 0) ;; *) usage ;; esac
 	bisect_autostart
-	bisect_next_check good
+	bisect_next_check $NAME_GOOD
 
 	# Perform all bisection computation, display and checkout
 	git bisect--helper --next-all $(test -f "$GIT_DIR/BISECT_HEAD" && echo --no-checkout)
@@ -316,18 +321,18 @@ bisect_next() {
 	# Check if we should exit because bisection is finished
 	if test $res -eq 10
 	then
-		bad_rev=$(git show-ref --hash --verify refs/bisect/bad)
+		bad_rev=$(git show-ref --hash --verify refs/bisect/$NAME_BAD)
 		bad_commit=$(git show-branch $bad_rev)
-		echo "# first bad commit: $bad_commit" >>"$GIT_DIR/BISECT_LOG"
+		echo "# first $NAME_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/good-*")
-		for skipped in $(git rev-list refs/bisect/bad --not $good_revs)
+		good_revs=$(git for-each-ref --format="%(objectname)" "refs/bisect/$NAME_GOOD-*")
+		for skipped in $(git rev-list refs/bisect/$NAME_BAD --not $good_revs)
 		do
 			skipped_commit=$(git show-branch $skipped)
-			echo "# possible first bad commit: $skipped_commit" >>"$GIT_DIR/BISECT_LOG"
+			echo "# possible first $NAME_BAD commit: $skipped_commit" >>"$GIT_DIR/BISECT_LOG"
 		done
 		exit $res
 	fi
@@ -421,7 +426,7 @@ bisect_replay () {
 		start)
 			cmd="bisect_start $rev"
 			eval "$cmd" ;;
-		good|bad|skip)
+		$NAME_GOOD|$NAME_BAD|skip)
 			bisect_write "$command" "$rev" ;;
 		*)
 			die "$(gettext "?? what are you talking about?")" ;;
@@ -455,9 +460,9 @@ exit code \$res from '\$command' is < 0 or >= 128" >&2
 			state='skip'
 		elif [ $res -gt 0 ]
 		then
-			state='bad'
+			state="$NAME_BAD"
 		else
-			state='good'
+			state="$NAME_GOOD"
 		fi
 
 		# We have to use a subshell because "bisect_state" can exit.
@@ -466,7 +471,7 @@ exit code \$res from '\$command' is < 0 or >= 128" >&2
 
 		cat "$GIT_DIR/BISECT_RUN"
 
-		if sane_grep "first bad commit could be any of" "$GIT_DIR/BISECT_RUN" \
+		if sane_grep "first $NAME_BAD commit could be any of" "$GIT_DIR/BISECT_RUN" \
 			>/dev/null
 		then
 			gettextln "bisect run cannot continue any more" >&2
@@ -480,7 +485,7 @@ exit code \$res from '\$command' is < 0 or >= 128" >&2
 			exit $res
 		fi
 
-		if sane_grep "is the first bad commit" "$GIT_DIR/BISECT_RUN" >/dev/null
+		if sane_grep "is the first $NAME_BAD commit" "$GIT_DIR/BISECT_RUN" >/dev/null
 		then
 			gettextln "bisect run success"
 			exit 0;
-- 
1.7.1

[PATCH v2 3/7] bisect: simplify the addition of new bisect terms

[Antoine Delaite]

We create a file BISECT_TERMS in the repository .git to be read during a
bisection. The fonctions to be changed if we add new terms are quite
few.
In git-bisect.sh :
	check_and_set_terms
	bisect_voc
In bisect.c :
	handle_bad_merge_base

Signed-off-by: Antoine Delaite <antoine.delaite@ensimag.grenoble-inp.fr>
Signed-off-by: Louis Stuber <stuberl@ensimag.grenoble-inp.fr>
Signed-off-by: Valentin Duperray <Valentin.Duperray@ensimag.imag.fr>
Signed-off-by: Franck Jonas <Franck.Jonas@ensimag.imag.fr>
Signed-off-by: Lucien Kong <Lucien.Kong@ensimag.imag.fr>
Signed-off-by: Thomas Nguy <Thomas.Nguy@ensimag.imag.fr>
Signed-off-by: Huynh Khoi Nguyen Nguyen <Huynh-Khoi-Nguyen.Nguyen@ensimag.imag.fr>
Signed-off-by: Matthieu Moy <Matthieu.Moy@grenoble-inp.fr>
---
 bisect.c      |   33 +++++++++++++++++++++++++--
 git-bisect.sh |   66 +++++++++++++++++++++++++++++++++++++++++++++++++++-----
 2 files changed, 90 insertions(+), 9 deletions(-)

diff --git a/bisect.c b/bisect.c
index eb2f555..827d2f3 100644
--- a/bisect.c
+++ b/bisect.c
@@ -745,7 +745,10 @@ static void handle_bad_merge_base(void)
 				"between %s and [%s].\n",
 				bad_hex, bad_hex, good_hex);
 		} else {
-			die("BUG: terms %s/%s not managed", name_bad, name_good);
+			fprintf(stderr, "The merge base %s is %s.\n"
+				"This means the first commit marked %s is "
+				"between %s and [%s].\n",
+				bad_hex, name_bad, name_bad, bad_hex, good_hex);
 		}
 		exit(3);
 	}
@@ -900,6 +903,31 @@ static void show_diff_tree(const char *prefix, struct commit *commit)
 }
 
 /*
+ * The terms used for this bisect session are stored in
+ * BISECT_TERMS: it can be bad/good or new/old.
+ * We read them and store them to adapt the messages
+ * accordingly. Default is bad/good.
+ */
+void read_bisect_terms(void)
+{
+	struct strbuf str = STRBUF_INIT;
+	const char *filename = git_path("BISECT_TERMS");
+	FILE *fp = fopen(filename, "r");
+
+	if (!fp) {
+		die("could not read file '%s': %s", filename,
+			strerror(errno));
+	} else {
+		strbuf_getline(&str, fp, '\n');
+		name_bad = strbuf_detach(&str, NULL);
+		strbuf_getline(&str, fp, '\n');
+		name_good = strbuf_detach(&str, NULL);
+	}
+	strbuf_release(&str);
+	fclose(fp);
+}
+
+/*
  * We use the convention that exiting with an exit code 10 means that
  * the bisection process finished successfully.
  * In this case the calling shell script should exit 0.
@@ -915,8 +943,7 @@ int bisect_next_all(const char *prefix, int no_checkout)
 	const unsigned char *bisect_rev;
 	char bisect_rev_hex[GIT_SHA1_HEXSZ + 1];
 
-	name_bad="bad";
-	name_good="good";
+	read_bisect_terms();
 	if (read_bisect_refs())
 		die("reading bisect refs failed");
 
diff --git a/git-bisect.sh b/git-bisect.sh
index ce6412f..d63b4b0 100644
--- a/git-bisect.sh
+++ b/git-bisect.sh
@@ -77,6 +77,9 @@ bisect_start() {
 	orig_args=$(git rev-parse --sq-quote "$@")
 	bad_seen=0
 	eval=''
+	# start_bad_good is used to detect if we did a 
+	# 'git bisect start bad_rev good_rev'
+	start_bad_good=0
 	if test "z$(git rev-parse --is-bare-repository)" != zfalse
 	then
 		mode=--no-checkout
@@ -101,6 +104,9 @@ bisect_start() {
 				die "$(eval_gettext "'\$arg' does not appear to be a valid revision")"
 				break
 			}
+
+			start_bad_good=1
+
 			case $bad_seen in
 			0) state=$NAME_BAD ; bad_seen=1 ;;
 			*) state=$NAME_GOOD ;;
@@ -172,6 +178,11 @@ bisect_start() {
 	} &&
 	git rev-parse --sq-quote "$@" >"$GIT_DIR/BISECT_NAMES" &&
 	eval "$eval true" &&
+	if test $start_bad_good -eq 1 && test ! -s "$GIT_DIR/BISECT_TERMS"
+	then
+		echo "$NAME_BAD" >"$GIT_DIR/BISECT_TERMS" &&
+		echo "$NAME_GOOD" >>"$GIT_DIR/BISECT_TERMS"
+	fi &&
 	echo "git bisect start$orig_args" >>"$GIT_DIR/BISECT_LOG" || exit
 	#
 	# Check if we can proceed to the next bisect state.
@@ -232,6 +243,7 @@ bisect_skip() {
 bisect_state() {
 	bisect_autostart
 	state=$1
+	check_and_set_terms $state
 	case "$#,$state" in
 	0,*)
 		die "$(gettext "Please call 'bisect_state' with at least one argument.")" ;;
@@ -291,15 +303,17 @@ bisect_next_check() {
 		: bisect without $NAME_GOOD...
 		;;
 	*)
-
+		bad_syn=$(bisect_voc bad)
+		good_syn=$(bisect_voc good)
 		if test -s "$GIT_DIR/BISECT_START"
 		then
-			gettextln "You need to give me at least one good and one bad revision.
-(You can use \"git bisect bad\" and \"git bisect good\" for that.)" >&2
+
+			eval_gettextln "You need to give me at least one \$bad_syn and one \$good_syn revision.
+(You can use \"git bisect \$bad_syn\" and \"git bisect \$good_syn\" for that.)" >&2
 		else
-			gettextln "You need to start by \"git bisect start\".
-You then need to give me at least one good and one bad revision.
-(You can use \"git bisect bad\" and \"git bisect good\" for that.)" >&2
+			eval_gettextln "You need to start by \"git bisect start\".
+You then need to give me at least one \$good_syn and one \$bad_syn revision.
+(You can use \"git bisect \$bad_syn\" and \"git bisect \$good_syn\" for that.)" >&2
 		fi
 		exit 1 ;;
 	esac
@@ -402,6 +416,7 @@ bisect_clean_state() {
 	rm -f "$GIT_DIR/BISECT_LOG" &&
 	rm -f "$GIT_DIR/BISECT_NAMES" &&
 	rm -f "$GIT_DIR/BISECT_RUN" &&
+	rm -f "$GIT_DIR/BISECT_TERMS" &&
 	# Cleanup head-name if it got left by an old version of git-bisect
 	rm -f "$GIT_DIR/head-name" &&
 	git update-ref -d --no-deref BISECT_HEAD &&
@@ -422,6 +437,8 @@ bisect_replay () {
 			rev="$command"
 			command="$bisect"
 		fi
+		get_terms
+		check_and_set_terms "$command"
 		case "$command" in
 		start)
 			cmd="bisect_start $rev"
@@ -499,11 +516,48 @@ bisect_log () {
 	cat "$GIT_DIR/BISECT_LOG"
 }
 
+get_terms () {
+	if test -s "$GIT_DIR/BISECT_TERMS"
+	then
+		NAME_BAD="$(sed -n 1p "$GIT_DIR/BISECT_TERMS")"
+		NAME_GOOD="$(sed -n 2p "$GIT_DIR/BISECT_TERMS")"
+	fi
+}
+
+check_and_set_terms () {
+	cmd="$1"
+	case "$cmd" in
+	bad|good)
+		if test -s "$GIT_DIR/BISECT_TERMS" && test "$cmd" != "$NAME_BAD" && test "$cmd" != "$NAME_GOOD"
+		then
+			die "$(eval_gettext "Invalid command: you're currently in a \$NAME_BAD/\$NAME_GOOD bisect.")"
+		fi
+		case "$cmd" in
+		bad|good)
+			if ! test -s "$GIT_DIR/BISECT_TERMS"
+			then
+				echo "bad" >"$GIT_DIR/BISECT_TERMS" &&
+				echo "good" >>"$GIT_DIR/BISECT_TERMS"
+			fi
+			NAME_BAD="bad"
+			NAME_GOOD="good" ;;
+		esac ;;
+	esac
+}
+
+bisect_voc () {
+	case "$1" in
+	bad) echo "bad" ;;
+	good) echo "good" ;;
+	esac
+}
+
 case "$#" in
 0)
 	usage ;;
 *)
 	cmd="$1"
+	get_terms
 	shift
 	case "$cmd" in
 	help)
-- 
1.7.1

[PATCH v2 4/7] bisect: add the terms old/new

[Antoine Delaite]

When not looking for a regression during a bisect but for a fix or a
change in another given property, it can be confusing to use 'good'
and 'bad'.

This patch introduce `git bisect new` and `git bisect old` as an
alternative to 'bad' and good': the commits which have a certain
property must be marked as `new` and the ones which do not as `old`.

The output will be the first commit after the change in the property.
During a new/old bisect session you cannot use bad/good commands and
vice-versa.

`git bisect replay` works fine for old/new bisect sessions.

Some commands are still not available for old/new:

     * git bisect start [<new> [<old>...]] is not possible: the
       commits will be treated as bad and good.
     * git rev-list --bisect does not treat the revs/bisect/new and
       revs/bisect/old-SHA1 files.
     * git bisect visualize seem to work partially: the tags are
       displayed correctly but the tree is not limited to the bisect
       section.

Related discussions:

	- http://thread.gmane.org/gmane.comp.version-control.git/86063
		introduced bisect fix unfixed to find fix.
	- http://thread.gmane.org/gmane.comp.version-control.git/182398
		discussion around bisect yes/no or old/new.
	- http://thread.gmane.org/gmane.comp.version-control.git/199758
		last discussion and reviews

Signed-off-by: Antoine Delaite <antoine.delaite@ensimag.grenoble-inp.fr>
Signed-off-by: Louis Stuber <stuberl@ensimag.grenoble-inp.fr>
Signed-off-by: Valentin Duperray <Valentin.Duperray@ensimag.imag.fr>
Signed-off-by: Franck Jonas <Franck.Jonas@ensimag.imag.fr>
Signed-off-by: Lucien Kong <Lucien.Kong@ensimag.imag.fr>
Signed-off-by: Thomas Nguy <Thomas.Nguy@ensimag.imag.fr>
Signed-off-by: Huynh Khoi Nguyen Nguyen <Huynh-Khoi-Nguyen.Nguyen@ensimag.imag.fr>
Signed-off-by: Matthieu Moy <Matthieu.Moy@grenoble-inp.fr>
---
 Documentation/git-bisect.txt |   48 ++++++++++++++++++++++++++++++++++++++++-
 bisect.c                     |   11 +++++++--
 git-bisect.sh                |   30 +++++++++++++++++--------
 t/t6030-bisect-porcelain.sh  |   38 +++++++++++++++++++++++++++++++++
 4 files changed, 112 insertions(+), 15 deletions(-)

diff --git a/Documentation/git-bisect.txt b/Documentation/git-bisect.txt
index 4cb52a7..3c3021a 100644
--- a/Documentation/git-bisect.txt
+++ b/Documentation/git-bisect.txt
@@ -18,8 +18,8 @@ on the subcommand:
 
  git bisect help
  git bisect start [--no-checkout] [<bad> [<good>...]] [--] [<paths>...]
- git bisect bad [<rev>]
- git bisect good [<rev>...]
+ git bisect (bad|new) [<rev>]
+ git bisect (good|old) [<rev>...]
  git bisect skip [(<rev>|<range>)...]
  git bisect reset [<commit>]
  git bisect visualize
@@ -104,6 +104,35 @@ For example, `git bisect reset HEAD` will leave you on the current
 bisection commit and avoid switching commits at all, while `git bisect
 reset bisect/bad` will check out the first bad revision.
 
+
+Alternative terms: bisect new and bisect old
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+If you are not at ease with the terms "bad" and "good", perhaps
+because you are looking for the commit that introduced a fix, you can
+alternatively use "new" and "old" instead.
+But note that you cannot mix "bad" and good" with "new" and "old".
+
+------------------------------------------------
+git bisect new [<rev>]
+------------------------------------------------
+
+Marks the commit as new, e.g. "the bug is no longer there", if you are looking
+for a commit that fixed a bug, or "the feature that used to work is now broken
+at this point", if you are looking for a commit that introduced a bug.
+It is the equivalent of "git bisect bad [<rev>]".
+
+------------------------------------------------
+git bisect old [<rev>...]
+------------------------------------------------
+
+Marks the commit as old, as the opposite of 'git bisect new'.
+It is the equivalent of "git bisect good [<rev>...]".
+
+You must run `git bisect start` without commits as argument and run
+`git bisect new <rev>`/`git bisect old <rev>...` after to add the
+commits.
+
 Bisect visualize
 ~~~~~~~~~~~~~~~~
 
@@ -379,6 +408,21 @@ In this case, when 'git bisect run' finishes, bisect/bad will refer to a commit
 has at least one parent whose reachable graph is fully traversable in the sense
 required by 'git pack objects'.
 
+* Look for a fix instead of a regression in the code
++
+------------
+$ git bisect start
+$ git bisect new HEAD    # current commit is marked as new
+$ git bisect old HEAD~10 # the tenth commit from now is marked as old
+------------
++
+Let's consider the last commit has a given property, and that we are looking
+for the commit which introduced this property. For each commit the bisection
+guide us to, we will test if the property is present. If it is we will mark
+the commit as new with 'git bisect new', otherwise we will mark it as old.
+At the end of the bisect session, the result will be the first new commit (e.g
+the first one with the property).
+
 
 SEE ALSO
 --------
diff --git a/bisect.c b/bisect.c
index 827d2f3..eaa85b6 100644
--- a/bisect.c
+++ b/bisect.c
@@ -744,6 +744,11 @@ static void handle_bad_merge_base(void)
 				"This means the bug has been fixed "
 				"between %s and [%s].\n",
 				bad_hex, bad_hex, good_hex);
+		} else if (!strcmp(name_bad, "new")) {
+			fprintf(stderr, "The merge base %s is new.\n"
+				"The property has changed "
+				"between %s and [%s].\n",
+				bad_hex, bad_hex, good_hex);
 		} else {
 			fprintf(stderr, "The merge base %s is %s.\n"
 				"This means the first commit marked %s is "
@@ -776,11 +781,11 @@ static void handle_skipped_merge_base(const unsigned char *mb)
 }
 
 /*
- * "check_merge_bases" checks that merge bases are not "bad".
+ * "check_merge_bases" checks that merge bases are not "bad" (or "new").
  *
- * - If one is "bad", it means the user assumed something wrong
+ * - If one is "bad" (or "new"), it means the user assumed something wrong
  * and we must exit with a non 0 error code.
- * - If one is "good", that's good, we have nothing to do.
+ * - If one is "good" (or "old"), that's good, we have nothing to do.
  * - If one is "skipped", we can't know but we should warn.
  * - If we don't know, we should check it out and ask the user to test.
  */
diff --git a/git-bisect.sh b/git-bisect.sh
index d63b4b0..c012f5d 100644
--- a/git-bisect.sh
+++ b/git-bisect.sh
@@ -1,14 +1,16 @@
 #!/bin/sh
 
-USAGE='[help|start|bad|good|skip|next|reset|visualize|replay|log|run]'
+USAGE='[help|start|bad|good|new|old|skip|next|reset|visualize|replay|log|run]'
 LONG_USAGE='git bisect help
 	print this long help message.
 git bisect start [--no-checkout] [<bad> [<good>...]] [--] [<pathspec>...]
 	reset bisect state and start bisection.
-git bisect bad [<rev>]
-	mark <rev> a known-bad revision.
-git bisect good [<rev>...]
-	mark <rev>... known-good revisions.
+git bisect (bad|new) [<rev>]
+	mark <rev> a known-bad revision/
+		a revision after change in a given property.
+git bisect (good|old) [<rev>...]
+	mark <rev>... known-good revisions/
+		revisions before change in a given property.
 git bisect skip [(<rev>|<range>)...]
 	mark <rev>... untestable revisions.
 git bisect next
@@ -288,7 +290,7 @@ bisect_next_check() {
 		false
 		;;
 	t,,"$NAME_GOOD")
-		# have bad but not good.  we could bisect although
+		# have bad (or new) but not good (or old).  we could bisect although
 		# this is less optimum.
 		eval_gettextln "Warning: bisecting only with a \$NAME_BAD commit." >&2
 		if test -t 0
@@ -527,7 +529,7 @@ get_terms () {
 check_and_set_terms () {
 	cmd="$1"
 	case "$cmd" in
-	bad|good)
+	bad|good|new|old)
 		if test -s "$GIT_DIR/BISECT_TERMS" && test "$cmd" != "$NAME_BAD" && test "$cmd" != "$NAME_GOOD"
 		then
 			die "$(eval_gettext "Invalid command: you're currently in a \$NAME_BAD/\$NAME_GOOD bisect.")"
@@ -541,14 +543,22 @@ check_and_set_terms () {
 			fi
 			NAME_BAD="bad"
 			NAME_GOOD="good" ;;
+		new|old)
+			if ! test -s "$GIT_DIR/BISECT_TERMS"
+			then
+				echo "new" >"$GIT_DIR/BISECT_TERMS" &&
+				echo "old" >>"$GIT_DIR/BISECT_TERMS"
+			fi
+			NAME_BAD="new"
+			NAME_GOOD="old" ;;
 		esac ;;
 	esac
 }
 
 bisect_voc () {
 	case "$1" in
-	bad) echo "bad" ;;
-	good) echo "good" ;;
+	bad) echo "bad|old" ;;
+	good) echo "good|new" ;;
 	esac
 }
 
@@ -564,7 +574,7 @@ case "$#" in
 		git bisect -h ;;
 	start)
 		bisect_start "$@" ;;
-	bad|good)
+	bad|good|new|old)
 		bisect_state "$cmd" "$@" ;;
 	skip)
 		bisect_skip "$@" ;;
diff --git a/t/t6030-bisect-porcelain.sh b/t/t6030-bisect-porcelain.sh
index 9e2c203..2f2143b 100755
--- a/t/t6030-bisect-porcelain.sh
+++ b/t/t6030-bisect-porcelain.sh
@@ -759,4 +759,42 @@ test_expect_success '"git bisect bad HEAD" behaves as "git bisect bad"' '
 	git bisect reset
 '
 
+test_expect_success 'bisect starts with only one new' '
+	git bisect reset &&
+	git bisect start &&
+	git bisect new $HASH4 &&
+	git bisect next
+'
+
+test_expect_success 'bisect does not start with only one old' '
+	git bisect reset &&
+	git bisect start &&
+	git bisect old $HASH1 &&
+	test_must_fail git bisect next
+'
+
+test_expect_success 'bisect start with one new and old' '
+	git bisect reset &&
+	git bisect start &&
+	git bisect old $HASH1 &&
+	git bisect new $HASH4 &&
+	git bisect new &&
+	git bisect new >bisect_result &&
+	grep "$HASH2 is the first new commit" bisect_result &&
+	git bisect log > log_to_replay.txt &&
+	git bisect reset
+'
+
+test_expect_success 'bisect replay with old and new' '
+	git bisect replay log_to_replay.txt > bisect_result &&
+	grep "$HASH2 is the first new commit" bisect_result &&
+	git bisect reset
+'
+
+test_expect_success 'bisect cannot mix old/new and good/bad' '
+	git bisect start &&
+	git bisect bad $HASH4 &&
+	test_must_fail git bisect old $HASH1
+'
+
 test_done
-- 
1.7.1

Re: [PATCH v2 4/7] bisect: add the terms old/new

[Junio C Hamano]

Antoine Delaite <antoine.delaite@ensimag.grenoble-inp.fr> writes:

> Related discussions:
>
> 	- http://thread.gmane.org/gmane.comp.version-control.git/86063
> 		introduced bisect fix unfixed to find fix.
> 	- http://thread.gmane.org/gmane.comp.version-control.git/182398
> 		discussion around bisect yes/no or old/new.
> 	- http://thread.gmane.org/gmane.comp.version-control.git/199758
> 		last discussion and reviews

Hmph, recent reviews and discussions we had here do not count?

I do agree with Matthieu's review on the last round, which is still
not quite addressed in this round.  The current code only supports
good/bad and this series merely adds another hardcoded pair old/new,
which is disappointing, given that this is a very good opportunity
to place an infrastructure to allow other pairs like unfixed/fixed
building on top of the most generic old/new.

Re: [PATCH v2 2/7] bisect: replace hardcoded "bad|good" by variables

[Matthieu Moy]

Antoine Delaite <antoine.delaite@ensimag.grenoble-inp.fr> writes:

> -	if (!strcmp(refname, "bad")) {
> +	char good_prefix[256];
> +	strcpy(good_prefix, name_good);
> +	strcat(good_prefix, "-");

You are silently adding a restriction here: name_good must be small
enough to fit in a 256-bytes array. It's not a terrible restriction, but
what may happen if you break it is a real issue.

Either you have to enforce this restriction somewhere, or you should not
have the restriction at all. I'd vote for the second. strbuf is your
friend here.

> @@ -259,21 +264,21 @@ bisect_state() {
>  
>  bisect_next_check() {
>  	missing_good= missing_bad=
> -	git show-ref -q --verify refs/bisect/bad || missing_bad=t
> -	test -n "$(git for-each-ref "refs/bisect/good-*")" || missing_good=t
> +	git show-ref -q --verify refs/bisect/$NAME_BAD || missing_bad=t
> +	test -n "$(git for-each-ref "refs/bisect/$NAME_GOOD-*")" || missing_good=t

There are other restrictions here: $NAME_BAD must be an acceptable ref
name, and you're not quoting $NAME_BAD hence it must not contain shell
meta-characters (The requirements for ref names almost imply that, but
'foo/bar{a,b}' is accepted and will trigger some expansion if your
/bin/sh is bash for example).

Being an acceptable ref name is a constraint you have to check (Junio
already mentionned check-ref-format). I think quoting variables makes
sense too.

> @@ -421,7 +426,7 @@ bisect_replay () {
>  		start)
>  			cmd="bisect_start $rev"
>  			eval "$cmd" ;;
> -		good|bad|skip)
> +		$NAME_GOOD|$NAME_BAD|skip)

$NAME_GOOD and $NAME_BAD need quoting if you're not sure they don't
contain shell metacharacters.

-- 
Matthieu Moy
http://www-verimag.imag.fr/~moy/

Re: [PATCH v2 4/7] bisect: add the terms old/new

[Louis-Alexandre Stuber]

I agree this makes no sense hardcoding old/new once bisect terms is
considerred. It would have been a lot better if we had started
implementing bisect terms immediatly (but we thought old/new would
already be an appreciable step for most of users).

[PATCH v2 2/7] bisect: replace hardcoded "bad|good" by variables

[Antoine Delaite]

Matthieu Moy <Matthieu.Moy@grenoble-inp.fr> wrote: 

>Being an acceptable ref name is a constraint you have to check (Junio 
>already mentionned check-ref-format). I think quoting variables makes 
>sense too 

I don't get how 'git check-ref-format' works exactly. It says it needs 
at least one slash in the ref name. So it would not be good for bisect 
terms.
Then do we take the same format as branches ? 
( i.e 'git check-ref-format --branch' )

Thanks.

Re: [PATCH v2 2/7] bisect: replace hardcoded "bad|good" by variables

[Matthieu Moy]

Antoine Delaite <antoine.delaite@ensimag.grenoble-inp.fr> writes:

> Matthieu Moy <Matthieu.Moy@grenoble-inp.fr> wrote: 
>
>>Being an acceptable ref name is a constraint you have to check (Junio 
>>already mentionned check-ref-format). I think quoting variables makes 
>>sense too 
>
> I don't get how 'git check-ref-format' works exactly. It says it needs 
> at least one slash in the ref name. So it would not be good for bisect 
> terms.

At some point, refs/bisect/$good and refs/bisect/$bad-$sha1 will become
refs, so you should check refs/bisect/$good and refs/bisect/$bad with
check-ref-format (I think the -$sha1 suffix will be accepted by
construction).

-- 
Matthieu Moy
http://www-verimag.imag.fr/~moy/