bisect: use "$GIT_DIR/BISECT_START" to check if we are bisecting

It seems simpler and safer to use the BISECT_START file everywhere
to decide if we are bisecting or not, instead of using it in some
places and BISECT_NAMES in other places.

In commit 6459c7c6786aa9bda0c7a095c9db66c36da0e5f0 (Nov 18 2007,
Bisect: use "$GIT_DIR/BISECT_NAMES" to check if we are bisecting.),
we decided to use BISECT_NAMES but code changed a lot and we now
have to check BISECT_START first in the "bisect_start" function
anyway.

This patch also makes things a little bit safer by creating
the BISECT_START file first and deleting it last, and also by
adding checks in "bisect_clean_state".

Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/git-bisect.sh b/git-bisect.sh
index 4bcbaceb8bd6a5dc9021b2525f43ae5317a7d46a..991b2ef37e5121d89f40d1b10964bf5d5beed40b 100755 (executable)
--- a/git-bisect.sh
+++ b/git-bisect.sh
@@ -44,7 +44,7 @@ sq() {
 }
 
 bisect_autostart() {
-       test -f "$GIT_DIR/BISECT_NAMES" || {
+       test -s "$GIT_DIR/BISECT_START" || {
                echo >&2 'You need to start by "git bisect start"'
                if test -t 0
                then
@@ -98,7 +98,7 @@ bisect_start() {
        #
        # Get rid of any old bisect state.
        #
-       bisect_clean_state
+       bisect_clean_state || exit
 
        #
        # Check for one bad and then some good revisions.
@@ -146,8 +146,8 @@ bisect_start() {
        #
        # Write new start state.
        #
-       sq "$@" >"$GIT_DIR/BISECT_NAMES" &&
        echo "$start_head" >"$GIT_DIR/BISECT_START" &&
+       sq "$@" >"$GIT_DIR/BISECT_NAMES" &&
        eval "$eval" &&
        echo "git-bisect start$orig_args" >>"$GIT_DIR/BISECT_LOG" || exit
        #
@@ -226,7 +226,7 @@ bisect_next_check() {
                ;;
        *)
                THEN=''
-               test -f "$GIT_DIR/BISECT_NAMES" || {
+               test -s "$GIT_DIR/BISECT_START" || {
                        echo >&2 'You need to start by "git bisect start".'
                        THEN='then '
                }
@@ -392,16 +392,12 @@ bisect_visualize() {
 }
 
 bisect_reset() {
-       test -f "$GIT_DIR/BISECT_NAMES" || {
+       test -s "$GIT_DIR/BISECT_START" || {
                echo "We are not bisecting."
                return
        }
        case "$#" in
-       0) if [ -s "$GIT_DIR/BISECT_START" ]; then
-              branch=`cat "$GIT_DIR/BISECT_START"`
-          else
-              branch=master
-          fi ;;
+       0) branch=$(cat "$GIT_DIR/BISECT_START") ;;
        1) git show-ref --verify --quiet -- "refs/heads/$1" ||
               die "$1 does not seem to be a valid branch"
           branch="$1" ;;
@@ -416,14 +412,15 @@ bisect_clean_state() {
        git for-each-ref --format='%(refname) %(objectname)' refs/bisect/\* |
        while read ref hash
        do
-               git update-ref -d $ref $hash
+               git update-ref -d $ref $hash || exit
        done
-       rm -f "$GIT_DIR/BISECT_START"
-       rm -f "$GIT_DIR/BISECT_LOG"
-       rm -f "$GIT_DIR/BISECT_NAMES"
-       rm -f "$GIT_DIR/BISECT_RUN"
+       rm -f "$GIT_DIR/BISECT_LOG" &&
+       rm -f "$GIT_DIR/BISECT_NAMES" &&
+       rm -f "$GIT_DIR/BISECT_RUN" &&
        # Cleanup head-name if it got left by an old version of git-bisect
-       rm -f "$GIT_DIR/head-name"
+       rm -f "$GIT_DIR/head-name" &&
+
+       rm -f "$GIT_DIR/BISECT_START"
 }
 
 bisect_replay () {