@leroysheep / Socializer / commits / 8211462761

t5308: test reverse indexes with duplicate objects

A non-strict .idx has one entry for each object in the pack, even when multiple entries have the same object ID. Thus a pack ordered A, B, A, C has two .idx entries for A at distinct offsets. The corresponding per-pack reverse index must represent both entries and map them back to physical pack order. Existing reverse-index tests do not cover packs with duplicate objects. Add one and check that %(objectsize:disk) for B stops at the second A, rather than extending through it to C. Exercise both the on-disk and in-memory reverse-index implementations. As part of validating Git's handling of packs containing duplicate objects, cover their per-pack reverse indexes. Signed-off-by: Taylor Blau <ttaylorr@openai.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>

Taylor Blau committed Jul 24, 2026 at 16:05 UTC 82114627614c22b05c7c0919ad59ac8f225fe7d5
1 file changed +39
t/t5308-pack-detect-duplicates.sh
+39
index 0f84137867..4ff8f5b449 100755 --- a/t/t5308-pack-detect-duplicates.sh +++ b/t/t5308-pack-detect-duplicates.sh @@ -27,6 +27,11 @@ HI_SHA1=$EMPTY_BLOB # duplicate runs). MISSING_SHA1=$(test_oid missing_oid) +# Three distinct objects for tests where physical pack order matters. +A=$(test_oid packlib_7_0) +B=$LO_SHA1 +C=$HI_SHA1 + # git will never intentionally create packfiles with # duplicate objects, so we have to construct them by hand. # @@ -72,6 +77,40 @@ test_expect_success 'lookup in duplicated pack' ' test_cmp expect actual ' +test_expect_success 'duplicate entries remain in pack reverse index' ' + clear_packs && + { + pack_header 4 && + pack_obj $A && + pack_obj $B && + pack_obj $A && + pack_obj $C + } >physical-order.pack && + pack_trailer physical-order.pack && + + test_must_fail git index-pack --rev-index --stdin --strict \ + <physical-order.pack 2>err && + test_grep "appears twice in the pack" err && + + git index-pack --rev-index --stdin <physical-order.pack && + git show-index <"$(ls .git/objects/pack/pack-*.idx)" >offsets.raw && + + sort -n offsets.raw | grep -A1 "$B" | cut -d" " -f1 >adjacent && + echo $(($(tail -n1 adjacent) - $(head -n1 adjacent))) >expect && + echo "$B" >in && + + GIT_TEST_REV_INDEX_DIE_IN_MEMORY=1 \ + git cat-file --batch-check="%(objectsize:disk)" \ + <in >actual.disk && + GIT_TEST_REV_INDEX_DIE_ON_DISK=1 \ + git -c pack.readReverseIndex=false \ + cat-file --batch-check="%(objectsize:disk)" \ + <in >actual.mem && + + test_cmp expect actual.disk && + test_cmp expect actual.mem +' + test_expect_success 'index-pack can reject packs with duplicates' ' clear_packs && create_pack dups.pack 2 &&