t7003: ensure --prune-empty can prune root commit

New test to expose a bug in filter-branch whereby the root commit is
never pruned, even though its tree is empty and --prune-empty is given.

The setup isn't exactly pretty, but I couldn't think of a simpler way to
create a parallel commit graph sans the first commit.

Signed-off-by: Devin J. Pohly <djpohly@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/t/t7003-filter-branch.sh b/t/t7003-filter-branch.sh
index cb8fbd8e5e03a0ff5a176cc947419c357fd65d99..45372a1cba4460e61c3ba253f68a25951c24c4eb 100755 (executable)
--- a/t/t7003-filter-branch.sh
+++ b/t/t7003-filter-branch.sh
@@ -313,6 +313,27 @@ test_expect_success 'Tag name filtering allows slashes in tag names' '
        git cat-file tag X/2 > actual &&
        test_cmp expect actual
 '
        git cat-file tag X/2 > actual &&
        test_cmp expect actual
 '

+test_expect_success 'setup --prune-empty comparisons' '
+       git checkout --orphan master-no-a &&
+       git rm -rf . &&
+       unset test_tick &&
+       test_tick &&
+       GIT_COMMITTER_DATE="@0 +0000" GIT_AUTHOR_DATE="@0 +0000" &&
+       test_commit --notick B B.t B Bx &&
+       git checkout -b branch-no-a Bx &&
+       test_commit D D.t D Dx &&
+       mkdir dir &&
+       test_commit dir/D dir/D.t dir/D dir/Dx &&
+       test_commit E E.t E Ex &&
+       git checkout master-no-a &&
+       test_commit C C.t C Cx &&
+       git checkout branch-no-a &&
+       git merge Cx -m "Merge tag '\''C'\'' into branch" &&
+       git tag Fx &&
+       test_commit G G.t G Gx &&
+       test_commit H H.t H Hx &&
+       git checkout branch
+'

 
 test_expect_success 'Prune empty commits' '
        git rev-list HEAD > expect &&
 
 test_expect_success 'Prune empty commits' '
        git rev-list HEAD > expect &&


@@ -341,6 +362,15 @@ test_expect_success 'prune empty works even without index/tree filters' '
        test_cmp expect actual
 '
 
        test_cmp expect actual
 '
 

+test_expect_failure '--prune-empty is able to prune root commit' '
+       git rev-list branch-no-a >expect &&
+       git branch testing H &&
+       git filter-branch -f --prune-empty --index-filter "git update-index --remove A.t" testing &&
+       git rev-list testing >actual &&
+       git branch -D testing &&
+       test_cmp expect actual
+'
+

 test_expect_success '--remap-to-ancestor with filename filters' '
        git checkout master &&
        git reset --hard A &&
 test_expect_success '--remap-to-ancestor with filename filters' '
        git checkout master &&
        git reset --hard A &&