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>

diff --git a/Documentation/git-bisect.txt b/Documentation/git-bisect.txt
index 96585ae8d9455654b63e83d61e7c34a7aeb94291..0855b98b281c95830850b01a3db59a1ceb8f6eb2 100644 (file)
--- a/Documentation/git-bisect.txt
+++ b/Documentation/git-bisect.txt
@@ -78,7 +78,7 @@ Oh, and then after you want to reset to the original head, do a
 $ git bisect reset
 ------------------------------------------------
 
 $ git bisect reset
 ------------------------------------------------
 

-to get back to the master branch, instead of being in one of the
+to get back to the original branch, instead of being in one of the

 bisection branches ("git bisect start" will do that for you too,
 actually: it will reset the bisection state, and before it does that
 it checks that you're not using some old bisection branch).
 bisection branches ("git bisect start" will do that for you too,
 actually: it will reset the bisection state, and before it does that
 it checks that you're not using some old bisection branch).

diff --git a/git-bisect.sh b/git-bisect.sh
index 8e57e9a75dd9916d2c5a59f224859d1a22854c7f..54bfd71dad0c2f587de68742945ca52909df0c95 100755 (executable)
--- 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"
        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 "$head" in
        refs/heads/bisect)
        start_head=''
        case "$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)
                git checkout $branch || exit
                ;;
        refs/heads/*|$_x40)


@@ -324,8 +329,8 @@ bisect_next() {
        exit_if_skipped_commits "$bisect_rev"
 
        echo "Bisecting: $bisect_nr revisions left to test after this"
        exit_if_skipped_commits "$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 "$bisect_rev"
 }
        git branch -M new-bisect bisect
        git show-branch "$bisect_rev"
 }

diff --git a/t/t6030-bisect-porcelain.sh b/t/t6030-bisect-porcelain.sh
index 5e3e5445c730140ad6c2fa9cc5bda4a7029e7fbf..05f1e15c34cab66743d48b365479a000d641b23b 100755 (executable)
--- a/t/t6030-bisect-porcelain.sh
+++ b/t/t6030-bisect-porcelain.sh
@@ -284,6 +284,24 @@ test_expect_success 'bisect starting with a detached HEAD' '
 
 '
 
 
 '
 

+test_expect_success 'bisect refuses to start if branch bisect exists' '
+       git bisect reset &&
+       git branch bisect &&
+       test_must_fail git bisect start &&
+       git branch -d bisect &&
+       git checkout -b bisect &&
+       test_must_fail git bisect start &&
+       git checkout master &&
+       git branch -d bisect
+'
+
+test_expect_success 'bisect refuses to start if branch new-bisect exists' '
+       git bisect reset &&
+       git branch new-bisect &&
+       test_must_fail git bisect start &&
+       git branch -d new-bisect
+'
+

 #
 #
 test_done
 #
 #
 test_done