From ee831f7ddfc40e9144208c93e24d20ff0ad69194 Mon Sep 17 00:00:00 2001
From: Gerrit Pape <pape@smarden.org>
Date: Mon, 5 May 2008 07:43:00 +0000
Subject: git-bisect.sh: don't accidentally override existing branch "bisect"

If a branch named "bisect" or "new-bisect" already was created in the
repo by other means than git bisect, doing a git bisect used to override
the branch without a warning.  Now if the branch "bisect" or
"new-bisect" already exists, and it was not created by git bisect itself,
git bisect start fails with an appropriate error message.  Additionally,
if checking out a new bisect state fails due to a merge problem, git
bisect cleans up the temporary branch "new-bisect".

The accidental override has been noticed by Andres Salomon, reported
through
 http://bugs.debian.org/478647

Signed-off-by: Gerrit Pape <pape@smarden.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 git-bisect.sh | 19 ++++++++++++-------
 1 file changed, 12 insertions(+), 7 deletions(-)

(limited to 'git-bisect.sh')

diff --git a/git-bisect.sh b/git-bisect.sh
index 8e57e9a75..54bfd71da 100755
--- a/git-bisect.sh
+++ b/git-bisect.sh
@@ -65,14 +65,19 @@ bisect_start() {
 	head=$(GIT_DIR="$GIT_DIR" git symbolic-ref -q HEAD) ||
 	head=$(GIT_DIR="$GIT_DIR" git rev-parse --verify HEAD) ||
 	die "Bad HEAD - I need a HEAD"
+	#
+	# Check that we either already have BISECT_START, or that the
+	# branches bisect, new-bisect don't exist, to not override them.
+	#
+	test -s "$GIT_DIR/BISECT_START" ||
+		if git show-ref --verify -q refs/heads/bisect ||
+		    git show-ref --verify -q refs/heads/new-bisect; then
+			die 'The branches "bisect" and "new-bisect" must not exist.'
+		fi
 	start_head=''
 	case "$head" in
 	refs/heads/bisect)
-		if [ -s "$GIT_DIR/BISECT_START" ]; then
-		    branch=`cat "$GIT_DIR/BISECT_START"`
-		else
-		    branch=master
-		fi
+		branch=`cat "$GIT_DIR/BISECT_START"`
 		git checkout $branch || exit
 		;;
 	refs/heads/*|$_x40)
@@ -324,8 +329,8 @@ bisect_next() {
 	exit_if_skipped_commits "$bisect_rev"
 
 	echo "Bisecting: $bisect_nr revisions left to test after this"
-	git branch -f new-bisect "$bisect_rev"
-	git checkout -q new-bisect || exit
+	git branch -D new-bisect 2> /dev/null
+	git checkout -q -b new-bisect "$bisect_rev" || exit
 	git branch -M new-bisect bisect
 	git show-branch "$bisect_rev"
 }
-- 
cgit v1.2.1


From 42ba5ee776c00369ca72b76537ae622611a7b545 Mon Sep 17 00:00:00 2001
From: Christian Couder <chriscool@tuxfamily.org>
Date: Wed, 7 May 2008 23:54:28 +0200
Subject: bisect: print an error message when "git rev-list --bisect-vars"
 fails

Before this patch no error was printed when "git rev-list --bisect-vars"
failed. This can happen when bad and good revs are mistaken.

This patch prints an error message on stderr that describe the likely
failure cause.

Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 git-bisect.sh | 19 +++++++++++++++++--
 1 file changed, 17 insertions(+), 2 deletions(-)

(limited to 'git-bisect.sh')

diff --git a/git-bisect.sh b/git-bisect.sh
index 54bfd71da..b1800edaf 100755
--- a/git-bisect.sh
+++ b/git-bisect.sh
@@ -220,18 +220,33 @@ bisect_auto_next() {
 	bisect_next_check && bisect_next || :
 }
 
+eval_rev_list() {
+	_eval="$1"
+
+	eval $_eval
+	res=$?
+
+	if [ $res -ne 0 ]; then
+		echo >&2 "'git rev-list --bisect-vars' failed:"
+		echo >&2 "maybe you mistake good and bad revs?"
+		exit $res
+	fi
+
+	return $res
+}
+
 filter_skipped() {
 	_eval="$1"
 	_skip="$2"
 
 	if [ -z "$_skip" ]; then
-		eval $_eval
+		eval_rev_list "$_eval"
 		return
 	fi
 
 	# Let's parse the output of:
 	# "git rev-list --bisect-vars --bisect-all ..."
-	eval $_eval | while read hash line
+	eval_rev_list "$_eval" | while read hash line
 	do
 		case "$VARS,$FOUND,$TRIED,$hash" in
 			# We display some vars.
-- 
cgit v1.2.1