[PATCHv2] git bisect old/new

[Valentin Duperray <Valentin.Duperray@ensimag.imag.fr>]

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 the most
recent version of the property must be marked as `new` and the ones
with the older version 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.
     * thus, git bisect run <cmd> is not available for new/old.
     * 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.

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 |   43 ++++++++++++++-
 bisect.c                     |   84 +++++++++++++++++++++--------
 git-bisect.sh                |  121 ++++++++++++++++++++++++++++++++----------
 t/t6030-bisect-porcelain.sh  |   40 ++++++++++++++
 4 files changed, 236 insertions(+), 52 deletions(-)

diff --git a/Documentation/git-bisect.txt b/Documentation/git-bisect.txt
index e4f46bc..fc63894 100644
--- a/Documentation/git-bisect.txt
+++ b/Documentation/git-bisect.txt
@@ -18,8 +18,10 @@ 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 new [<rev>]
+ git bisect old [<rev>...]
  git bisect skip [(<rev>|<range>)...]
  git bisect reset [<commit>]
  git bisect visualize
@@ -104,6 +106,31 @@ 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>]
+------------------------------------------------
+
+Same as "git bisect bad [<rev>]".
+
+------------------------------------------------
+git bisect old [<rev>...]
+------------------------------------------------
+
+Same as "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
 ~~~~~~~~~~~~~~~~
 
@@ -374,6 +401,18 @@ 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		# Current version is fixed
+$ git bisect old bugged_version	# bugged_version was the last version
+				# known to be unfixed
+------------
++
+The "new" commits are the fixed ones and the "old" commits are the unfixed ones.
+At the end of the commit session, you will have the first fixed commit.
+
 
 SEE ALSO
 --------
diff --git a/bisect.c b/bisect.c
index 48acf73..38de2d5 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 *bisect_bad;
+static const char *bisect_good;
+
 /* bits #0-15 in revision.h */
 
 #define COUNTED		(1u<<16)
@@ -403,9 +406,10 @@ 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")) {
+	if (!strcmp(refname, bisect_bad)) {
 		current_bad_sha1 = sha1;
-	} else if (!prefixcmp(refname, "good-")) {
+	} else if (!prefixcmp(refname, "good-") ||
+			!prefixcmp(refname, "old-")) {
 		sha1_array_append(&good_revs, sha1);
 	} else if (!prefixcmp(refname, "skip-")) {
 		sha1_array_append(&skipped_revs, sha1);
@@ -633,7 +637,7 @@ 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", bisect_bad);
 	print_commit_list(tried, "%s\n", "%s\n");
 	if (bad)
 		printf("%s\n", sha1_to_hex(bad));
@@ -731,18 +735,25 @@ static void handle_bad_merge_base(void)
 	if (is_expected_rev(current_bad_sha1)) {
 		char *bad_hex = sha1_to_hex(current_bad_sha1);
 		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(bisect_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 {
+			fprintf(stderr, "The merge base %s is new.\n"
+				"The property has changed "
+				"between %s and [%s].\n",
+				bad_hex, bad_hex, good_hex);
+		}
 		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 mistake good and bad revs?\n");
+		"Maybe you mistake %s and %s revs?\n",
+		bisect_good, bisect_bad, bisect_good,
+		bisect_bad);
 	exit(1);
 }
 
@@ -754,19 +765,19 @@ 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, bisect_bad, mb_hex, bad_hex);
 	free(good_hex);
 }
 
 /*
- * "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.
  */
@@ -838,7 +849,7 @@ static void check_good_are_ancestors_of_bad(const char *prefix, int no_checkout)
 	int fd;
 
 	if (!current_bad_sha1)
-		die("a bad revision is needed");
+		die("a %s revision is needed", bisect_bad);
 
 	/* Check if file BISECT_ANCESTORS_OK exists. */
 	if (!stat(filename, &st) && S_ISREG(st.st_mode))
@@ -889,6 +900,31 @@ static void show_diff_tree(const char *prefix, struct commit *commit)
 }
 
 /*
+ * The terms used for this bisect session are stocked in
+ * BISECT_TERMS: it can be bad/good or new/old.
+ * We read them and stock 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) {
+		bisect_bad = "bad";
+		bisect_good = "good";
+	} else {
+	strbuf_getline(&str, fp, '\n');
+	bisect_bad = strbuf_detach(&str, NULL);
+	strbuf_getline(&str, fp, '\n');
+	bisect_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.
@@ -903,7 +939,7 @@ int bisect_next_all(const char *prefix, int no_checkout)
 	int reaches = 0, all = 0, nr, steps;
 	const unsigned char *bisect_rev;
 	char bisect_rev_hex[41];
-
+	read_bisect_terms();
 	if (read_bisect_refs())
 		die("reading bisect refs failed");
 
@@ -925,8 +961,9 @@ int bisect_next_all(const char *prefix, int no_checkout)
 		 */
 		exit_if_skipped_commits(tried, NULL);
 
-		printf("%s was both good and bad\n",
-		       sha1_to_hex(current_bad_sha1));
+		printf("%s was both %s and %s\n",
+		       sha1_to_hex(current_bad_sha1), bisect_good,
+		       bisect_bad);
 		exit(1);
 	}
 
@@ -941,7 +978,8 @@ int bisect_next_all(const char *prefix, int no_checkout)
 
 	if (!hashcmp(bisect_rev, current_bad_sha1)) {
 		exit_if_skipped_commits(tried, current_bad_sha1);
-		printf("%s is the first bad commit\n", bisect_rev_hex);
+		printf("%s is the first %s commit\n", bisect_rev_hex,
+			bisect_bad);
 		show_diff_tree(prefix, revs.commits->item);
 		/* This means the bisection process succeeded. */
 		exit(10);
@@ -953,6 +991,8 @@ int bisect_next_all(const char *prefix, int no_checkout)
 	       "(roughly %d step%s)\n", nr, (nr == 1 ? "" : "s"),
 	       steps, (steps == 1 ? "" : "s"));
 
+	free((char*)bisect_bad);
+	free((char*)bisect_good);
+
 	return bisect_checkout(bisect_rev_hex, no_checkout);
 }
-
diff --git a/git-bisect.sh b/git-bisect.sh
index 99efbe8..6ba87e5 100755
--- 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|skip|next|reset|visualize|replay|log|run|new|old]'
 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
@@ -32,6 +34,8 @@ 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"
+BISECT_BAD="bad"
+BISECT_GOOD="good"
 
 bisect_head()
 {
@@ -75,6 +79,7 @@ bisect_start() {
 	orig_args=$(git rev-parse --sq-quote "$@")
 	bad_seen=0
 	eval=''
+	start_bad_good=0
 	if test "z$(git rev-parse --is-bare-repository)" != zfalse
 	then
 		mode=--no-checkout
@@ -99,6 +104,16 @@ bisect_start() {
 				die "$(eval_gettext "'\$arg' does not appear to be a valid revision")"
 				break
 			}
+
+			if test -s "$GIT_DIR/BISECT_TERMS"
+			then
+				if $(sed -n 1p "$GIT_DIR/BISECT_TERMS") != 'bad'
+				then
+					die "$(gettext "you are already bisecting in old/new mode")"
+				fi
+			fi
+			start_bad_good=1
+
 			case $bad_seen in
 			0) state='bad' ; bad_seen=1 ;;
 			*) state='good' ;;
@@ -170,6 +185,11 @@ bisect_start() {
 	} &&
 	git rev-parse --sq-quote "$@" >"$GIT_DIR/BISECT_NAMES" &&
 	eval "$eval true" &&
+	if test $start_bad_good -eq 1 -a ! -s "$GIT_DIR/BISECT_TERMS"
+	then
+		echo "bad" >"$GIT_DIR/BISECT_TERMS" &&
+		echo "good" >>"$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.
@@ -184,9 +204,12 @@ 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")" ;;
+		"$BISECT_BAD")
+			tag="$state" ;;
+		"$BISECT_GOOD"|skip)
+			tag="$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 +253,12 @@ bisect_state() {
 	case "$#,$state" in
 	0,*)
 		die "$(gettext "Please call 'bisect_state' with at least one argument.")" ;;
-	1,bad|1,good|1,skip)
+	1,"$BISECT_BAD"|1,"$BISECT_GOOD"|1,skip)
 		rev=$(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,"$BISECT_BAD"|*,"$BISECT_GOOD"|*,skip)
 		shift
 		eval=''
 		for rev in "$@"
@@ -246,8 +269,8 @@ bisect_state() {
 		done
 		eval "$eval"
 		check_expected_revs "$@" ;;
-	*,bad)
-		die "$(gettext "'git bisect bad' can take only one argument.")" ;;
+	*,"$BISECT_BAD")
+		die "$(gettext "'git bisect $BISECT_BAD' can take only one argument.")" ;;
 	*)
 		usage ;;
 	esac
@@ -256,21 +279,21 @@ bisect_state() {
 
 bisect_next_check() {
 	missing_good= missing_bad=
-	git show-ref -q --verify refs/bisect/bad || missing_bad=t
-	test -n "$(git for-each-ref "refs/bisect/good-*")" || missing_good=t
+	git show-ref -q --verify refs/bisect/$BISECT_BAD || missing_bad=t
+	test -n "$(git for-each-ref "refs/bisect/$BISECT_GOOD-*")" || missing_good=t
 
 	case "$missing_good,$missing_bad,$1" in
 	,,*)
-		: have both good and bad - ok
+		: have both good and bad or old and new - ok
 		;;
 	*,)
 		# do not have both but not asked to fail - just report.
 		false
 		;;
-	t,,good)
-		# have bad but not good.  we could bisect although
+	t,,"$BISECT_GOOD")
+		# have bad (or new) but not good (or old).  we could bisect although
 		# this is less optimum.
-		gettextln "Warning: bisecting only with a bad commit." >&2
+		gettextln "Warning: bisecting only with a $BISECT_BAD commit." >&2
 		if test -t 0
 		then
 			# TRANSLATORS: Make sure to include [Y] and [n] in your
@@ -280,17 +303,17 @@ bisect_next_check() {
 			read yesno
 			case "$yesno" in [Nn]*) exit 1 ;; esac
 		fi
-		: bisect without good...
+		: bisect without $BISECT_GOOD...
 		;;
 	*)
 
 		if test -s "$GIT_DIR/BISECT_START"
 		then
-			gettextln "You need to give me at least one good and one bad revisions.
+			gettextln "You need to give me at least one good and one bad (or one old and one new) revisions.
 (You can use \"git bisect bad\" and \"git bisect good\" for that.)" >&2
 		else
 			gettextln "You need to start by \"git bisect start\".
-You then need to give me at least one good and one bad revisions.
+You then need to give me at least one good and one bad (or one old and one new) revisions.
 (You can use \"git bisect bad\" and \"git bisect good\" for that.)" >&2
 		fi
 		exit 1 ;;
@@ -304,7 +327,7 @@ bisect_auto_next() {
 bisect_next() {
 	case "$#" in 0) ;; *) usage ;; esac
 	bisect_autostart
-	bisect_next_check good
+	bisect_next_check $BISECT_GOOD
 
 	# Perform all bisection computation, display and checkout
 	git bisect--helper --next-all $(test -f "$GIT_DIR/BISECT_HEAD" && echo --no-checkout)
@@ -378,6 +401,7 @@ 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 "$GIT_DIR/head-name" &&
 	git update-ref -d --no-deref BISECT_HEAD &&
@@ -398,11 +422,13 @@ bisect_replay () {
 			rev="$command"
 			command="$bisect"
 		fi
+		get_terms
+		check_and_set_terms "$command"
 		case "$command" in
 		start)
 			cmd="bisect_start $rev"
 			eval "$cmd" ;;
-		good|bad|skip)
+		good|bad|skip|old|new)
 			bisect_write "$command" "$rev" ;;
 		*)
 			die "$(gettext "?? what are you talking about?")" ;;
@@ -436,9 +462,9 @@ exit code \$res from '\$command' is < 0 or >= 128" >&2
 			state='skip'
 		elif [ $res -gt 0 ]
 		then
-			state='bad'
+			state="$BISECT_BAD"
 		else
-			state='good'
+			state="$BISECT_GOOD"
 		fi
 
 		# We have to use a subshell because "bisect_state" can exit.
@@ -447,7 +473,7 @@ 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 $BISECT_BAD commit could be any of" "$GIT_DIR/BISECT_RUN" \
 			> /dev/null
 		then
 			gettextln "bisect run cannot continue any more" >&2
@@ -461,7 +487,7 @@ 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 $BISECT_BAD commit" "$GIT_DIR/BISECT_RUN" > /dev/null
 		then
 			gettextln "bisect run success"
 			exit 0;
@@ -475,18 +501,57 @@ bisect_log () {
 	cat "$GIT_DIR/BISECT_LOG"
 }
 
+get_terms () {
+	if test -s "$GIT_DIR/BISECT_TERMS"
+	then
+		BISECT_BAD="$(sed -n 1p "$GIT_DIR/BISECT_TERMS")"
+		BISECT_GOOD="$(sed -n 2p "$GIT_DIR/BISECT_TERMS")"
+	fi
+}
+
+check_and_set_terms () {
+	cmd="$1"
+	case "$cmd" in
+	bad|good|new|old)
+		if test -s "$GIT_DIR/BISECT_TERMS" -a "$cmd" != "$BISECT_BAD" -a "$cmd" != "$BISECT_GOOD"
+		then
+			die "$(eval_gettext "Invalid command : you're currently in a \$BISECT_BAD/\$BISECT_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
+			BISECT_BAD="bad"
+			BISECT_GOOD="good" ;;
+		new|old)
+			if test ! -s "$GIT_DIR/BISECT_TERMS"
+			then
+				echo "new" >"$GIT_DIR/BISECT_TERMS" &&
+				echo "old" >>"$GIT_DIR/BISECT_TERMS"
+			fi
+			BISECT_BAD="new"
+			BISECT_GOOD="old" ;;
+		esac ;;
+	esac
+}
+
 case "$#" in
 0)
 	usage ;;
 *)
 	cmd="$1"
+	get_terms
+	check_and_set_terms "$cmd"
 	shift
 	case "$cmd" in
 	help)
 		git bisect -h ;;
 	start)
 		bisect_start "$@" ;;
-	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 72e28ee..c4a5d6b 100755
--- a/t/t6030-bisect-porcelain.sh
+++ b/t/t6030-bisect-porcelain.sh
@@ -741,6 +741,46 @@ test_expect_success 'bisect: demonstrate identification of damage boundary' "
 		test \$rc = 0' &&
 	check_same BROKEN_HASH6 bisect/bad &&
 	git bisect reset
+	git checkout master
+
 "
 
+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 || return 1
+	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
-- 
1.7.8