Merge branch 'dp/filter-branch-prune-empty'

"git filter-branch --prune-empty" drops a single-parent commit that
becomes a no-op, but did not drop a root commit whose tree is empty.

* dp/filter-branch-prune-empty:
p7000: add test for filter-branch with --prune-empty
filter-branch: fix --prune-empty on parentless commits
t7003: ensure --prune-empty removes entire branch when applicable
t7003: ensure --prune-empty can prune root commit

diff --git a/Documentation/git-filter-branch.txt b/Documentation/git-filter-branch.txt
index 0a09698c033fb2e1cdf68aa33eed4f109a034d5f..6e4bb022043faeddd363c899872e7de96c926c1c 100644 (file)
--- a/Documentation/git-filter-branch.txt
+++ b/Documentation/git-filter-branch.txt
@@ -167,14 +167,12 @@ to other tags will be rewritten to point to the underlying commit.
        project root. Implies <<Remap_to_ancestor>>.
 
 --prune-empty::
-       Some kind of filters will generate empty commits, that left the tree
-       untouched.  This switch allow git-filter-branch to ignore such
-       commits.  Though, this switch only applies for commits that have one
-       and only one parent, it will hence keep merges points. Also, this
-       option is not compatible with the use of `--commit-filter`. Though you
-       just need to use the function 'git_commit_non_empty_tree "$@"' instead
-       of the `git commit-tree "$@"` idiom in your commit filter to make that
-       happen.
+       Some filters will generate empty commits that leave the tree untouched.
+       This option instructs git-filter-branch to remove such commits if they
+       have exactly one or zero non-pruned parents; merge commits will
+       therefore remain intact.  This option cannot be used together with
+       `--commit-filter`, though the same effect can be achieved by using the
+       provided `git_commit_non_empty_tree` function in a commit filter.
 
 --original <namespace>::
        Use this option to set the namespace where the original commits

diff --git a/git-filter-branch.sh b/git-filter-branch.sh
index 86b2ff1e07614846465109dcb4b9afed11013839..2b8cdba157d9cd822acc88b7ec58cecda0149b85 100755 (executable)
--- a/git-filter-branch.sh
+++ b/git-filter-branch.sh
@@ -46,6 +46,8 @@ git_commit_non_empty_tree()
 {
        if test $# = 3 && test "$1" = $(git rev-parse "$3^{tree}"); then
                map "$3"
+       elif test $# = 1 && test "$1" = 4b825dc642cb6eb9a060e54bf8d69288fbee4904; then
+               :
        else
                git commit-tree "$@"
        fi

diff --git a/t/perf/p7000-filter-branch.sh b/t/perf/p7000-filter-branch.sh
index 15ee5d1d53391f38017cfd26bd23d94082a47365..b029586ccb2c8b3fd746a6c0bbdaca3966d42fa7 100755 (executable)
--- a/t/perf/p7000-filter-branch.sh
+++ b/t/perf/p7000-filter-branch.sh
@@ -16,4 +16,9 @@ test_perf 'noop filter' '
        git filter-branch -f base..HEAD
 '
 
+test_perf 'noop prune-empty' '
+       git checkout --detach tip &&
+       git filter-branch -f --prune-empty base..HEAD
+'
+
 test_done

diff --git a/t/t7003-filter-branch.sh b/t/t7003-filter-branch.sh
index cb8fbd8e5e03a0ff5a176cc947419c357fd65d99..7cb60799be1a109e2210350137c8754a5bc4bb7d 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
 '
+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 &&
@@ -341,6 +362,22 @@ test_expect_success 'prune empty works even without index/tree filters' '
        test_cmp expect actual
 '
 
+test_expect_success '--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 '--prune-empty is able to prune entire branch' '
+       git branch prune-entire B &&
+       git filter-branch -f --prune-empty --index-filter "git update-index --remove A.t B.t" prune-entire &&
+       test_path_is_missing .git/refs/heads/prune-entire &&
+       test_must_fail git reflog exists refs/heads/prune-entire
+'
+
 test_expect_success '--remap-to-ancestor with filename filters' '
        git checkout master &&
        git reset --hard A &&