git-bisect.sh: don't accidentally override existing branch "bisect"
[git/git.git] / git-bisect.sh
index 8e57e9a..54bfd71 100755 (executable)
@@ -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"
 }