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| author | Lidong Yan <502024330056@smail.nju.edu.cn> | 2025-06-09 08:18:44 +0000 |
|---|---|---|
| committer | Junio C Hamano <gitster@pobox.com> | 2025-06-09 09:04:47 -0700 |
| commit | 81cd1eef7dfc3edcdeaea1a2e8d5e31cc10e244a (patch) | |
| tree | 6c4fd32cd91e84e907316e5a1b4be72c8cfb2d4b | |
| parent | fcfe60668e05ffde2610bfef9045797618c145ac (diff) | |
pack-bitmap: remove checks before bitmap_free
In pack-bitmap.c:find_boundary_objects(), the roots_bitmap is only freed
if cascade_pseudo_merges_1() fails. However, cascade_pseudo_merges_1()
uses roots_bitmap as a mutable reference without taking ownership of it.
As a result, if cascade_pseudo_merges_1() succeeds, roots_bitmap is leaked.
And this leak currently lacks a dedicated test to detect it.
To fix this leak, remove if cascade_pseudo_merges_1() succeed check and
always calling bitmap_free(roots_bitmap);
To trigger this leak, we need roots_bitmap that contains at least one
pseudo merge. So that we can use pseudo merge bitmap when we compute roots
reachable bitmap. Here we create two commits: first A then B. Add A
to the pseudo-merge and perform a traversal over the range A..B.
In this scenario, the "haves" set will be {A}, and cascade_pseudo_merges_1
will succeed, thereby exposing the leak due to the missing roots_bitmap
cleanup.
Signed-off-by: Lidong Yan <502024330056@smail.nju.edu.cn>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
| -rw-r--r-- | pack-bitmap.c | 4 | ||||
| -rwxr-xr-x | t/t5333-pseudo-merge-bitmaps.sh | 17 |
2 files changed, 19 insertions, 2 deletions
diff --git a/pack-bitmap.c b/pack-bitmap.c index ac6d62b980..8727f316de 100644 --- a/pack-bitmap.c +++ b/pack-bitmap.c @@ -1363,8 +1363,8 @@ static struct bitmap *find_boundary_objects(struct bitmap_index *bitmap_git, bitmap_set(roots_bitmap, pos); } - if (!cascade_pseudo_merges_1(bitmap_git, cb.base, roots_bitmap)) - bitmap_free(roots_bitmap); + cascade_pseudo_merges_1(bitmap_git, cb.base, roots_bitmap); + bitmap_free(roots_bitmap); } /* diff --git a/t/t5333-pseudo-merge-bitmaps.sh b/t/t5333-pseudo-merge-bitmaps.sh index 56674db562..ba5ae6a00c 100755 --- a/t/t5333-pseudo-merge-bitmaps.sh +++ b/t/t5333-pseudo-merge-bitmaps.sh @@ -445,4 +445,21 @@ test_expect_success 'pseudo-merge closure' ' ) ' +test_expect_success 'use pseudo-merge in boundary traversal' ' + git init pseudo-merge-boundary-traversal && + ( + cd pseudo-merge-boundary-traversal && + + git config bitmapPseudoMerge.test.pattern refs/ && + git config pack.useBitmapBoundaryTraversal true && + + test_commit A && + git repack -adb && + test_commit B && + + nr=$(git rev-list --count --use-bitmap-index HEAD~1..HEAD) && + test 1 -eq "$nr" + ) +' + test_done |