add--interactive: handle initial commit better

diff --git a/git-bisect.sh b/git-bisect.sh
index 5385249890698632dedcaf8dda03d865f66abca9..393fa355849f88d6c5227f90cbf6cbb45b39631e 100755 (executable)
--- a/git-bisect.sh
+++ b/git-bisect.sh
@@ -26,6 +26,9 @@ OPTIONS_SPEC=
 . git-sh-setup
 require_work_tree
 
+_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"
+
 sq() {
        @@PERL@@ -e '
                for (@ARGV) {
@@ -60,7 +63,8 @@ bisect_start() {
        # top-of-line master first!
        #
        head=$(GIT_DIR="$GIT_DIR" git symbolic-ref HEAD) ||
-       die "Bad HEAD - I need a symbolic ref"
+       head=$(GIT_DIR="$GIT_DIR" git rev-parse --verify HEAD) ||
+       die "Bad HEAD - I need a HEAD"
        case "$head" in
        refs/heads/bisect)
                if [ -s "$GIT_DIR/head-name" ]; then
@@ -70,7 +74,7 @@ bisect_start() {
                fi
                git checkout $branch || exit
                ;;
-       refs/heads/*)
+       refs/heads/*|$_x40)
                [ -s "$GIT_DIR/head-name" ] && die "won't bisect on seeked tree"
                echo "${head#refs/heads/}" >"$GIT_DIR/head-name"
                ;;