t5326: test multi-pack bitmap behavior
This patch introduces a new test, t5326, which tests the basic functionality of multi-pack bitmaps. Some trivial behavior is tested, such as: - Whether bitmaps can be generated with more than one pack. - Whether clones can be served with all objects in the bitmap. - Whether follow-up fetches can be served with some objects outside of the server's bitmap These use lib-bitmap's tests (which in turn were pulled from t5310), and we cover cases where the MIDX represents both a single pack and multiple packs. In addition, some non-trivial and MIDX-specific behavior is tested, too, including: - Whether multi-pack bitmaps behave correctly with respect to the pack-reuse machinery when the base for some object is selected from a different pack than the delta. - Whether multi-pack bitmaps correctly respect the pack.preferBitmapTips configuration. Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Taylor Blau committed
Aug 31, 2021 at 16:52 UTC
c51f5a6437c62c5b231a4632896becd545c7e620
1 file changed
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t/t5326-multi-pack-bitmaps.sh
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+#!/bin/sh
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+
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+test_description='exercise basic multi-pack bitmap functionality'
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+. ./test-lib.sh
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+. "${TEST_DIRECTORY}/lib-bitmap.sh"
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+
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+# We'll be writing our own midx and bitmaps, so avoid getting confused by the
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+# automatic ones.
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+GIT_TEST_MULTI_PACK_INDEX=0
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+GIT_TEST_MULTI_PACK_INDEX_WRITE_BITMAP=0
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+
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+objdir=.git/objects
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+midx=$objdir/pack/multi-pack-index
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+
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+# midx_pack_source <obj>
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+midx_pack_source () {
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+ test-tool read-midx --show-objects .git/objects | grep "^$1 " | cut -f2
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+}
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+
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+setup_bitmap_history
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+
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+test_expect_success 'enable core.multiPackIndex' '
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+ git config core.multiPackIndex true
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+'
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+
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+test_expect_success 'create single-pack midx with bitmaps' '
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+ git repack -ad &&
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+ git multi-pack-index write --bitmap &&
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+ test_path_is_file $midx &&
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+ test_path_is_file $midx-$(midx_checksum $objdir).bitmap &&
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+ test_path_is_file $midx-$(midx_checksum $objdir).rev
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+'
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+
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+basic_bitmap_tests
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+
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+test_expect_success 'create new additional packs' '
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+ for i in $(test_seq 1 16)
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+ do
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+ test_commit "$i" &&
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+ git repack -d || return 1
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+ done &&
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+
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+ git checkout -b other2 HEAD~8 &&
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+ for i in $(test_seq 1 8)
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+ do
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+ test_commit "side-$i" &&
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+ git repack -d || return 1
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+ done &&
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+ git checkout second
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+'
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+
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+test_expect_success 'create multi-pack midx with bitmaps' '
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+ git multi-pack-index write --bitmap &&
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+
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+ ls $objdir/pack/pack-*.pack >packs &&
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+ test_line_count = 25 packs &&
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+
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+ test_path_is_file $midx &&
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+ test_path_is_file $midx-$(midx_checksum $objdir).bitmap &&
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+ test_path_is_file $midx-$(midx_checksum $objdir).rev
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+'
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+
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+basic_bitmap_tests
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+
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+test_expect_success '--no-bitmap is respected when bitmaps exist' '
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+ git multi-pack-index write --bitmap &&
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+
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+ test_commit respect--no-bitmap &&
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+ git repack -d &&
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+
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+ test_path_is_file $midx &&
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+ test_path_is_file $midx-$(midx_checksum $objdir).bitmap &&
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+ test_path_is_file $midx-$(midx_checksum $objdir).rev &&
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+
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+ git multi-pack-index write --no-bitmap &&
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+
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+ test_path_is_file $midx &&
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+ test_path_is_missing $midx-$(midx_checksum $objdir).bitmap &&
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+ test_path_is_missing $midx-$(midx_checksum $objdir).rev
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+'
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+
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+test_expect_success 'setup midx with base from later pack' '
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+ # Write a and b so that "a" is a delta on top of base "b", since Git
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+ # prefers to delete contents out of a base rather than add to a shorter
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+ # object.
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+ test_seq 1 128 >a &&
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+ test_seq 1 130 >b &&
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+
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+ git add a b &&
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+ git commit -m "initial commit" &&
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+
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+ a=$(git rev-parse HEAD:a) &&
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+ b=$(git rev-parse HEAD:b) &&
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+
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+ # In the first pack, "a" is stored as a delta to "b".
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+ p1=$(git pack-objects .git/objects/pack/pack <<-EOF
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+ $a
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+ $b
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+ EOF
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+ ) &&
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+
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+ # In the second pack, "a" is missing, and "b" is not a delta nor base to
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+ # any other object.
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+ p2=$(git pack-objects .git/objects/pack/pack <<-EOF
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+ $b
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+ $(git rev-parse HEAD)
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+ $(git rev-parse HEAD^{tree})
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+ EOF
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+ ) &&
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+
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+ git prune-packed &&
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+ # Use the second pack as the preferred source, so that "b" occurs
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+ # earlier in the MIDX object order, rendering "a" unusable for pack
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+ # reuse.
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+ git multi-pack-index write --bitmap --preferred-pack=pack-$p2.idx &&
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+
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+ have_delta $a $b &&
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+ test $(midx_pack_source $a) != $(midx_pack_source $b)
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+'
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+
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+rev_list_tests 'full bitmap with backwards delta'
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+
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+test_expect_success 'clone with bitmaps enabled' '
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+ git clone --no-local --bare . clone-reverse-delta.git &&
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+ test_when_finished "rm -fr clone-reverse-delta.git" &&
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+
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+ git rev-parse HEAD >expect &&
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+ git --git-dir=clone-reverse-delta.git rev-parse HEAD >actual &&
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+ test_cmp expect actual
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+'
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+
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+bitmap_reuse_tests() {
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+ from=$1
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+ to=$2
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+
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+ test_expect_success "setup pack reuse tests ($from -> $to)" '
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+ rm -fr repo &&
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+ git init repo &&
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+ (
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+ cd repo &&
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+ test_commit_bulk 16 &&
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+ git tag old-tip &&
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+
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+ git config core.multiPackIndex true &&
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+ if test "MIDX" = "$from"
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+ then
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+ git repack -Ad &&
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+ git multi-pack-index write --bitmap
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+ else
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+ git repack -Adb
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+ fi
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+ )
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+ '
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+
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+ test_expect_success "build bitmap from existing ($from -> $to)" '
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+ (
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+ cd repo &&
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+ test_commit_bulk --id=further 16 &&
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+ git tag new-tip &&
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+
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+ if test "MIDX" = "$to"
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+ then
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+ git repack -d &&
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+ git multi-pack-index write --bitmap
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+ else
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+ git repack -Adb
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+ fi
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+ )
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+ '
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+
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+ test_expect_success "verify resulting bitmaps ($from -> $to)" '
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+ (
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+ cd repo &&
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+ git for-each-ref &&
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+ git rev-list --test-bitmap refs/tags/old-tip &&
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+ git rev-list --test-bitmap refs/tags/new-tip
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+ )
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+ '
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+}
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+
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+bitmap_reuse_tests 'pack' 'MIDX'
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+bitmap_reuse_tests 'MIDX' 'pack'
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+bitmap_reuse_tests 'MIDX' 'MIDX'
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+
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+test_expect_success 'missing object closure fails gracefully' '
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+ rm -fr repo &&
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+ git init repo &&
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+ test_when_finished "rm -fr repo" &&
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+ (
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+ cd repo &&
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+
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+ test_commit loose &&
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+ test_commit packed &&
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+
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+ # Do not pass "--revs"; we want a pack without the "loose"
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+ # commit.
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+ git pack-objects $objdir/pack/pack <<-EOF &&
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+ $(git rev-parse packed)
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+ EOF
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+
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+ test_must_fail git multi-pack-index write --bitmap 2>err &&
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+ grep "doesn.t have full closure" err &&
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+ test_path_is_missing $midx
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+ )
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+'
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+
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+test_expect_success 'setup partial bitmaps' '
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+ test_commit packed &&
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+ git repack &&
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+ test_commit loose &&
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+ git multi-pack-index write --bitmap 2>err &&
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+ test_path_is_file $midx &&
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+ test_path_is_file $midx-$(midx_checksum $objdir).bitmap &&
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+ test_path_is_file $midx-$(midx_checksum $objdir).rev
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+'
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+
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+basic_bitmap_tests HEAD~
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+
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+test_expect_success 'removing a MIDX clears stale bitmaps' '
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+ rm -fr repo &&
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+ git init repo &&
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+ test_when_finished "rm -fr repo" &&
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+ (
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+ cd repo &&
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+ test_commit base &&
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+ git repack &&
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+ git multi-pack-index write --bitmap &&
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+
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+ # Write a MIDX and bitmap; remove the MIDX but leave the bitmap.
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+ stale_bitmap=$midx-$(midx_checksum $objdir).bitmap &&
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+ stale_rev=$midx-$(midx_checksum $objdir).rev &&
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+ rm $midx &&
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+
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+ # Then write a new MIDX.
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+ test_commit new &&
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+ git repack &&
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+ git multi-pack-index write --bitmap &&
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+
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+ test_path_is_file $midx &&
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+ test_path_is_file $midx-$(midx_checksum $objdir).bitmap &&
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+ test_path_is_file $midx-$(midx_checksum $objdir).rev &&
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+ test_path_is_missing $stale_bitmap &&
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+ test_path_is_missing $stale_rev
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+ )
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+'
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+
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+test_expect_success 'pack.preferBitmapTips' '
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+ git init repo &&
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+ test_when_finished "rm -fr repo" &&
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+ (
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+ cd repo &&
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+
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+ test_commit_bulk --message="%s" 103 &&
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+
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+ git log --format="%H" >commits.raw &&
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+ sort <commits.raw >commits &&
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+
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+ git log --format="create refs/tags/%s %H" HEAD >refs &&
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+ git update-ref --stdin <refs &&
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+
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+ git multi-pack-index write --bitmap &&
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+ test_path_is_file $midx &&
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+ test_path_is_file $midx-$(midx_checksum $objdir).bitmap &&
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+ test_path_is_file $midx-$(midx_checksum $objdir).rev &&
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+
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+ test-tool bitmap list-commits | sort >bitmaps &&
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+ comm -13 bitmaps commits >before &&
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+ test_line_count = 1 before &&
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+
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+ perl -ne "printf(\"create refs/tags/include/%d \", $.); print" \
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+ <before | git update-ref --stdin &&
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+
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+ rm -fr $midx-$(midx_checksum $objdir).bitmap &&
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+ rm -fr $midx-$(midx_checksum $objdir).rev &&
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+ rm -fr $midx &&
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+
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+ git -c pack.preferBitmapTips=refs/tags/include \
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+ multi-pack-index write --bitmap &&
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+ test-tool bitmap list-commits | sort >bitmaps &&
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+ comm -13 bitmaps commits >after &&
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+
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+ ! test_cmp before after
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+ )
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+'
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+
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+test_done