bisect: simplify the addition of new bisect terms

We create a file BISECT_TERMS in the repository .git to be read during a
bisection. There's no user-interface yet, but "git bisect" works if terms
other than old/new or bad/good are set in .git/BISECT_TERMS. The
fonctions to be changed if we add new terms are quite few.

In git-bisect.sh:
	check_and_set_terms
	bisect_voc

Co-authored-by: Louis Stuber <stuberl@ensimag.grenoble-inp.fr>
Tweaked-by: Matthieu Moy <Matthieu.Moy@imag.fr>
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@imag.fr>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 71 insertions, 8 deletions

diff --git a/git-bisect.sh b/git-bisect.sh
index fcbed22..dcd7e59 100755
--- a/git-bisect.sh
+++ b/git-bisect.sh
@@ -77,6 +77,7 @@ bisect_start() {
 	orig_args=$(git rev-parse --sq-quote "$@")
 	bad_seen=0
 	eval=''
+	must_write_terms=0
 	if test "z$(git rev-parse --is-bare-repository)" != zfalse
 	then
 		mode=--no-checkout
@@ -101,6 +102,14 @@ bisect_start() {
 				die "$(eval_gettext "'\$arg' does not appear to be a valid revision")"
 				break
 			}
+
+			# The user ran "git bisect start <sha1>
+			# <sha1>", hence did not explicitly specify
+			# the terms, but we are already starting to
+			# set references named with the default terms,
+			# and won't be able to change afterwards.
+			must_write_terms=1
+
 			case $bad_seen in
 			0) state=$TERM_BAD ; bad_seen=1 ;;
 			*) state=$TERM_GOOD ;;
@@ -172,6 +181,10 @@ bisect_start() {
 	} &&
 	git rev-parse --sq-quote "$@" >"$GIT_DIR/BISECT_NAMES" &&
 	eval "$eval true" &&
+	if test $must_write_terms -eq 1
+	then
+		write_terms "$TERM_BAD" "$TERM_GOOD"
+	fi &&
 	echo "git bisect start$orig_args" >>"$GIT_DIR/BISECT_LOG" || exit
 	#
 	# Check if we can proceed to the next bisect state.
@@ -232,6 +245,7 @@ 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 +305,17 @@ bisect_next_check() {
 		: bisect without $TERM_GOOD...
 		;;
 	*)
-
+		bad_syn=$(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 +418,7 @@ 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 "$GIT_DIR/head-name" &&
 	git update-ref -d --no-deref BISECT_HEAD &&
@@ -422,11 +439,13 @@ bisect_replay () {
 			rev="$command"
 			command="$bisect"
 		fi
+		get_terms
+		check_and_set_terms "$command"
 		case "$command" in
 		start)
 			cmd="bisect_start $rev"
 			eval "$cmd" ;;
-		$TERM_GOOD|$TERM_BAD|skip)
+		"$TERM_GOOD"|"$TERM_BAD"|skip)
 			bisect_write "$command" "$rev" ;;
 		*)
 			die "$(gettext "?? what are you talking about?")" ;;
@@ -499,18 +518,62 @@ bisect_log () {
 	cat "$GIT_DIR/BISECT_LOG"
 }
 
+get_terms () {
+	if test -s "$GIT_DIR/BISECT_TERMS"
+	then
+		{
+		read TERM_BAD
+		read TERM_GOOD
+		} <"$GIT_DIR/BISECT_TERMS"
+	fi
+}
+
+write_terms () {
+	TERM_BAD=$1
+	TERM_GOOD=$2
+	printf '%s\n%s\n' "$TERM_BAD" "$TERM_GOOD" >"$GIT_DIR/BISECT_TERMS"
+}
+
+check_and_set_terms () {
+	cmd="$1"
+	case "$cmd" in
+	skip|start|terms) ;;
+	*)
+		if test -s "$GIT_DIR/BISECT_TERMS" && test "$cmd" != "$TERM_BAD" && test "$cmd" != "$TERM_GOOD"
+		then
+			die "$(eval_gettext "Invalid command: you're currently in a \$TERM_BAD/\$TERM_GOOD bisect.")"
+		fi
+		case "$cmd" in
+		bad|good)
+			if ! test -s "$GIT_DIR/BISECT_TERMS"
+			then
+				write_terms bad good
+			fi
+			;;
+		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)
 		git bisect -h ;;
 	start)
 		bisect_start "$@" ;;
-	bad|good)
+	bad|good|"$TERM_BAD"|"$TERM_GOOD")
 		bisect_state "$cmd" "$@" ;;
 	skip)
 		bisect_skip "$@" ;;