Eliminate confusing "won't bisect on seeked tree" failure

This error message is very confusing---it doesn't tell the user
anything about how to fix the situation. And the actual fix
for the situation ("git bisect reset") does a checkout of a
potentially random branch, (compared to what the user wants to
be on for the bisect she is starting).

The simplest way to eliminate the confusion is to just make
"git bisect start" do the cleanup itself. There's no significant
loss of safety here since we already have a general safety in
the form of the reflog.

Note: We preserve the warning for any cogito users. We do this
by switching from .git/head-name to .git/BISECT_START for the
extra state, (which is a more descriptive name anyway).

Signed-off-by: Carl Worth <cworth@cworth.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/git-bisect.sh b/git-bisect.sh
index 74715edf0b197376250e5d111407a36a6c237678..2c32d0b9ebcdb9bf43124721e109cfac72149990 100755 (executable)
--- a/git-bisect.sh
+++ b/git-bisect.sh
@@ -67,16 +67,18 @@ bisect_start() {
        die "Bad HEAD - I need a HEAD"
        case "$head" in
        refs/heads/bisect)
-               if [ -s "$GIT_DIR/head-name" ]; then
-                   branch=`cat "$GIT_DIR/head-name"`
+               if [ -s "$GIT_DIR/BISECT_START" ]; then
+                   branch=`cat "$GIT_DIR/BISECT_START"`
                else
                    branch=master
                fi
                git checkout $branch || exit
                ;;
        refs/heads/*|$_x40)
+               # This error message should only be triggered by cogito usage,
+               # and cogito users should understand it relates to cg-seek.
                [ -s "$GIT_DIR/head-name" ] && die "won't bisect on seeked tree"
-               echo "${head#refs/heads/}" >"$GIT_DIR/head-name"
+               echo "${head#refs/heads/}" >"$GIT_DIR/BISECT_START"
                ;;
        *)
                die "Bad HEAD - strange symbolic ref"
@@ -353,8 +355,8 @@ bisect_reset() {
                return
        }
        case "$#" in
-       0) if [ -s "$GIT_DIR/head-name" ]; then
-              branch=`cat "$GIT_DIR/head-name"`
+       0) if [ -s "$GIT_DIR/BISECT_START" ]; then
+              branch=`cat "$GIT_DIR/BISECT_START"`
           else
               branch=master
           fi ;;
@@ -365,7 +367,9 @@ bisect_reset() {
            usage ;;
        esac
        if git checkout "$branch"; then
+               # Cleanup head-name if it got left by an old version of git-bisect
                rm -f "$GIT_DIR/head-name"
+               rm -f "$GIT_DIR/BISECT_START"
                bisect_clean_state
        fi
 }

diff --git a/t/t6030-bisect-porcelain.sh b/t/t6030-bisect-porcelain.sh
index ec71123f4be187c1399c90dc806dbae53cda5b7f..4908e878fee48069fbdc339f17ad6e865111ae00 100755 (executable)
--- a/t/t6030-bisect-porcelain.sh
+++ b/t/t6030-bisect-porcelain.sh
@@ -260,7 +260,7 @@ test_expect_success 'bisect starting with a detached HEAD' '
        git checkout master^ &&
        HEAD=$(git rev-parse --verify HEAD) &&
        git bisect start &&
-       test $HEAD = $(cat .git/head-name) &&
+       test $HEAD = $(cat .git/BISECT_START) &&
        git bisect reset &&
        test $HEAD = $(git rev-parse --verify HEAD)