# Test this inner rbyd data-structure

# test with a number of different erase values
defines.ERASE_VALUE = [0xff, 0x00, 0x1b, -1]

[cases.test_rbyd_fetch]
in = 'lfs.c'
code = '''
    lfs_t lfs;
    lfs_init(&lfs, cfg) => 0;

    lfs_rbyd_t rbyd_init = {
        .block = 0,
        .trunk = 0,
        .noff = 0,
        .rev = 1,
        .crc = 0,
        .count = 0,
        .erased = true,
    };
    lfs_rbyd_t rbyd;

    // try an empty commit
    rbyd = rbyd_init;
    lfs_bd_erase(&lfs, rbyd.block) => 0;
    lfs_rbyd_commit(&lfs, &rbyd, NULL) => 0;
    lfs_rbyd_fetch(&lfs, &rbyd, rbyd.block, NULL) => 0;

    // commit with one attribute
    rbyd = rbyd_init;
    lfs_bd_erase(&lfs, rbyd.block) => 0;
    lfs_rbyd_commit(&lfs, &rbyd,
            LFS_MKRATTR(UATTR, 1, 0, &(uint32_t){0xaaaaaaaa}, 4, NULL)) => 0;
    lfs_rbyd_fetch(&lfs, &rbyd, rbyd.block, NULL) => 0;

    // commit with two attributes
    rbyd = rbyd_init;
    lfs_bd_erase(&lfs, rbyd.block) => 0;
    lfs_rbyd_commit(&lfs, &rbyd,
            LFS_MKRATTR(UATTR, 1, 0, &(uint32_t){0xaaaaaaaa}, 4,
            LFS_MKRATTR(UATTR, 2, 0, &(uint32_t){0xbbbbbbbb}, 4, NULL))) => 0;
    lfs_rbyd_fetch(&lfs, &rbyd, rbyd.block, NULL) => 0;
'''

[cases.test_rbyd_multi_fetch]
in = 'lfs.c'
code = '''
    lfs_t lfs;
    lfs_init(&lfs, cfg) => 0;

    lfs_rbyd_t rbyd_init = {
        .block = 0,
        .trunk = 0,
        .noff = 0,
        .rev = 1,
        .crc = 0,
        .count = 0,
        .erased = true,
    };
    lfs_rbyd_t rbyd;

    // try an empty commit
    rbyd = rbyd_init;
    lfs_bd_erase(&lfs, rbyd.block) => 0;
    lfs_rbyd_commit(&lfs, &rbyd, NULL) => 0;
    lfs_rbyd_fetch(&lfs, &rbyd, rbyd.block, NULL) => 0;

    // commit with one attribute
    rbyd = rbyd_init;
    lfs_bd_erase(&lfs, rbyd.block) => 0;
    lfs_rbyd_commit(&lfs, &rbyd, NULL) => 0;
    lfs_rbyd_commit(&lfs, &rbyd,
            LFS_MKRATTR(UATTR, 1, 0, &(uint32_t){0xaaaaaaaa}, 4, NULL)) => 0;
    lfs_rbyd_fetch(&lfs, &rbyd, rbyd.block, NULL) => 0;

    // commit with two attributes
    rbyd = rbyd_init;
    lfs_bd_erase(&lfs, rbyd.block) => 0;
    lfs_rbyd_commit(&lfs, &rbyd,
            LFS_MKRATTR(UATTR, 1, 0, &(uint32_t){0xaaaaaaaa}, 4, NULL)) => 0;
    lfs_rbyd_commit(&lfs, &rbyd,
            LFS_MKRATTR(UATTR, 2, 0, &(uint32_t){0xbbbbbbbb}, 4, NULL)) => 0;
    lfs_rbyd_fetch(&lfs, &rbyd, rbyd.block, NULL) => 0;
'''

# [cases.test_rbyd_fetchmatch]
# [cases.test_rbyd_multi_fetchmatch]

[cases.test_rbyd_lookup]
in = 'lfs.c'
code = '''
    lfs_t lfs;
    lfs_init(&lfs, cfg) => 0;

    lfs_rbyd_t rbyd_init = {
        .block = 0,
        .trunk = 0,
        .noff = 0,
        .rev = 1,
        .crc = 0,
        .count = 0,
        .erased = true,
    };
    lfs_rbyd_t rbyd;
    lfs_off_t off;
    lfs_size_t size;

    // try an empty commit
    rbyd = rbyd_init;
    lfs_bd_erase(&lfs, rbyd.block) => 0;
    lfs_rbyd_commit(&lfs, &rbyd, NULL) => 0;

    // TODO test in-between lookups for consistently finding the next >= tag?
    lfs_rbyd_lookup(&lfs, &rbyd, 0, &off, &size)
            => LFS_ERR_NOENT;
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 1, 0), &off, &size)
            => LFS_ERR_NOENT;

    lfs_rbyd_fetch(&lfs, &rbyd, rbyd.block, NULL) => 0;
    lfs_rbyd_lookup(&lfs, &rbyd, 0, &off, &size)
            => LFS_ERR_NOENT;
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 1, 0), &off, &size)
            => LFS_ERR_NOENT;

    // commit with one attribute
    rbyd = rbyd_init;
    lfs_bd_erase(&lfs, rbyd.block) => 0;
    lfs_rbyd_commit(&lfs, &rbyd,
            LFS_MKRATTR(UATTR, 1, 0, &(uint32_t){0xaaaaaaaa}, 4, NULL)) => 0;

    lfs_rbyd_lookup(&lfs, &rbyd, 0, &off, &size)
            => LFS_MKRTAG(UATTR, 1, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 1, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 1, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 2, 0), &off, &size)
            => LFS_ERR_NOENT;

    lfs_rbyd_fetch(&lfs, &rbyd, rbyd.block, NULL) => 0;
    lfs_rbyd_lookup(&lfs, &rbyd, 0, &off, &size)
            => LFS_MKRTAG(UATTR, 1, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 1, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 1, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 2, 0), &off, &size)
            => LFS_ERR_NOENT;

    // commit with two attributes
    rbyd = rbyd_init;
    lfs_bd_erase(&lfs, rbyd.block) => 0;
    lfs_rbyd_commit(&lfs, &rbyd,
            LFS_MKRATTR(UATTR, 1, 0, &(uint32_t){0xaaaaaaaa}, 4,
            LFS_MKRATTR(UATTR, 2, 0, &(uint32_t){0xbbbbbbbb}, 4, NULL))) => 0;

    lfs_rbyd_lookup(&lfs, &rbyd, 0, &off, &size)
            => LFS_MKRTAG(UATTR, 1, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 1, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 1, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 2, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 2, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 3, 0), &off, &size)
            => LFS_ERR_NOENT;

    lfs_rbyd_fetch(&lfs, &rbyd, rbyd.block, NULL) => 0;
    lfs_rbyd_lookup(&lfs, &rbyd, 0, &off, &size)
            => LFS_MKRTAG(UATTR, 1, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 1, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 1, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 2, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 2, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 3, 0), &off, &size)
            => LFS_ERR_NOENT;
'''

[cases.test_rbyd_multi_lookup]
in = 'lfs.c'
code = '''
    lfs_t lfs;
    lfs_init(&lfs, cfg) => 0;

    lfs_rbyd_t rbyd_init = {
        .block = 0,
        .trunk = 0,
        .noff = 0,
        .rev = 1,
        .crc = 0,
        .count = 0,
        .erased = true,
    };
    lfs_rbyd_t rbyd;
    lfs_off_t off;
    lfs_size_t size;

    // try an empty commit
    rbyd = rbyd_init;
    lfs_bd_erase(&lfs, rbyd.block) => 0;
    lfs_rbyd_commit(&lfs, &rbyd, NULL) => 0;

    lfs_rbyd_lookup(&lfs, &rbyd, 0, &off, &size)
            => LFS_ERR_NOENT;
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 1, 0), &off, &size)
            => LFS_ERR_NOENT;

    lfs_rbyd_fetch(&lfs, &rbyd, rbyd.block, NULL) => 0;
    // TODO move these extra checks (for 0, in-between, enoent) to other tests
    lfs_rbyd_lookup(&lfs, &rbyd, 0, &off, &size)
            => LFS_ERR_NOENT;
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 1, 0), &off, &size)
            => LFS_ERR_NOENT;

    // commit with one attribute
    rbyd = rbyd_init;
    lfs_bd_erase(&lfs, rbyd.block) => 0;
    lfs_rbyd_commit(&lfs, &rbyd,
            LFS_MKRATTR(UATTR, 1, 0, &(uint32_t){0xaaaaaaaa}, 4, NULL)) => 0;

    lfs_rbyd_lookup(&lfs, &rbyd, 0, &off, &size)
            => LFS_MKRTAG(UATTR, 1, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 1, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 1, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 2, 0), &off, &size)
            => LFS_ERR_NOENT;

    lfs_rbyd_fetch(&lfs, &rbyd, rbyd.block, NULL) => 0;
    lfs_rbyd_lookup(&lfs, &rbyd, 0, &off, &size)
            => LFS_MKRTAG(UATTR, 1, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 1, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 1, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 2, 0), &off, &size)
            => LFS_ERR_NOENT;

    // commit with two attributes
    rbyd = rbyd_init;
    lfs_bd_erase(&lfs, rbyd.block) => 0;
    lfs_rbyd_commit(&lfs, &rbyd,
            LFS_MKRATTR(UATTR, 1, 0, &(uint32_t){0xaaaaaaaa}, 4, NULL)) => 0;
    lfs_rbyd_commit(&lfs, &rbyd,
            LFS_MKRATTR(UATTR, 2, 0, &(uint32_t){0xbbbbbbbb}, 4, NULL)) => 0;

    lfs_rbyd_lookup(&lfs, &rbyd, 0, &off, &size)
            => LFS_MKRTAG(UATTR, 1, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 1, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 1, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 2, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 2, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 3, 0), &off, &size)
            => LFS_ERR_NOENT;

    lfs_rbyd_fetch(&lfs, &rbyd, rbyd.block, NULL) => 0;
    lfs_rbyd_lookup(&lfs, &rbyd, 0, &off, &size)
            => LFS_MKRTAG(UATTR, 1, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 1, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 1, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 2, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 2, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 3, 0), &off, &size)
            => LFS_ERR_NOENT;
'''

[cases.test_rbyd_traverse]
in = 'lfs.c'
code = '''
    lfs_t lfs;
    lfs_init(&lfs, cfg) => 0;

    lfs_rbyd_t rbyd_init = {
        .block = 0,
        .trunk = 0,
        .noff = 0,
        .rev = 1,
        .crc = 0,
        .count = 0,
        .erased = true,
    };
    lfs_rbyd_t rbyd;
    lfs_off_t off;
    lfs_size_t size;
    lfs_srtag_t tag;

    // traverse requires correct biasing of the weights in the rbyd tree
    // so that lookups return strictly the tag greater than or equal to
    // the tag requested
    rbyd = rbyd_init;
    rbyd = rbyd_init;
    lfs_bd_erase(&lfs, rbyd.block) => 0;
    lfs_rbyd_commit(&lfs, &rbyd,
            LFS_MKRATTR(UATTR, 1, 0, &(uint32_t){0xaaaaaaaa}, 4,
            LFS_MKRATTR(UATTR, 2, 0, &(uint32_t){0xbbbbbbbb}, 4, NULL))) => 0;

    tag = lfs_rbyd_lookup(&lfs, &rbyd, 0, &off, &size);
    assert(tag == LFS_MKRTAG(UATTR, 1, 0));
    tag = lfs_rbyd_lookup(&lfs, &rbyd, lfs_rtag_inc(tag), &off, &size);
    assert(tag == LFS_MKRTAG(UATTR, 2, 0));
    tag = lfs_rbyd_lookup(&lfs, &rbyd, lfs_rtag_inc(tag), &off, &size);
    assert(tag == LFS_ERR_NOENT);

    lfs_rbyd_fetch(&lfs, &rbyd, rbyd.block, NULL) => 0;
    tag = lfs_rbyd_lookup(&lfs, &rbyd, 0, &off, &size);
    assert(tag == LFS_MKRTAG(UATTR, 1, 0));
    tag = lfs_rbyd_lookup(&lfs, &rbyd, lfs_rtag_inc(tag), &off, &size);
    assert(tag == LFS_MKRTAG(UATTR, 2, 0));
    tag = lfs_rbyd_lookup(&lfs, &rbyd, lfs_rtag_inc(tag), &off, &size);
    assert(tag == LFS_ERR_NOENT);
'''

[cases.test_rbyd_multi_traverse]
in = 'lfs.c'
code = '''
    lfs_t lfs;
    lfs_init(&lfs, cfg) => 0;

    lfs_rbyd_t rbyd_init = {
        .block = 0,
        .trunk = 0,
        .noff = 0,
        .rev = 1,
        .crc = 0,
        .count = 0,
        .erased = true,
    };
    lfs_rbyd_t rbyd;
    lfs_off_t off;
    lfs_size_t size;
    lfs_srtag_t tag;

    // traverse requires correct biasing of the weights in the rbyd tree
    // so that lookups return strictly the tag greater than or equal to
    // the tag requested
    rbyd = rbyd_init;
    rbyd = rbyd_init;
    lfs_bd_erase(&lfs, rbyd.block) => 0;
    lfs_rbyd_commit(&lfs, &rbyd,
            LFS_MKRATTR(UATTR, 1, 0, &(uint32_t){0xaaaaaaaa}, 4, NULL)) => 0;
    lfs_rbyd_commit(&lfs, &rbyd,
            LFS_MKRATTR(UATTR, 2, 0, &(uint32_t){0xbbbbbbbb}, 4, NULL)) => 0;

    tag = lfs_rbyd_lookup(&lfs, &rbyd, 0, &off, &size);
    assert(tag == LFS_MKRTAG(UATTR, 1, 0));
    tag = lfs_rbyd_lookup(&lfs, &rbyd, lfs_rtag_inc(tag), &off, &size);
    assert(tag == LFS_MKRTAG(UATTR, 2, 0));
    tag = lfs_rbyd_lookup(&lfs, &rbyd, lfs_rtag_inc(tag), &off, &size);
    assert(tag == LFS_ERR_NOENT);

    lfs_rbyd_fetch(&lfs, &rbyd, rbyd.block, NULL) => 0;
    tag = lfs_rbyd_lookup(&lfs, &rbyd, 0, &off, &size);
    assert(tag == LFS_MKRTAG(UATTR, 1, 0));
    tag = lfs_rbyd_lookup(&lfs, &rbyd, lfs_rtag_inc(tag), &off, &size);
    assert(tag == LFS_MKRTAG(UATTR, 2, 0));
    tag = lfs_rbyd_lookup(&lfs, &rbyd, lfs_rtag_inc(tag), &off, &size);
    assert(tag == LFS_ERR_NOENT);
'''

[cases.test_rbyd_bifoliate]
in = 'lfs.c'
code = '''
    lfs_t lfs;
    lfs_init(&lfs, cfg) => 0;

    lfs_rbyd_t rbyd_init = {
        .block = 0,
        .trunk = 0,
        .noff = 0,
        .rev = 1,
        .crc = 0,
        .count = 0,
        .erased = true,
    };
    lfs_rbyd_t rbyd;
    lfs_off_t off;
    lfs_size_t size;

    // create a split in the leaves
    //          <b
    //    =>  .-'|
    // 1      1  2
    rbyd = rbyd_init;
    lfs_bd_erase(&lfs, rbyd.block) => 0;
    lfs_rbyd_commit(&lfs, &rbyd,
            LFS_MKRATTR(UATTR, 1, 0, &(uint32_t){0xaaaaaaaa}, 4,
            LFS_MKRATTR(UATTR, 2, 0, &(uint32_t){0xbbbbbbbb}, 4, NULL))) => 0;

    lfs_rbyd_fetch(&lfs, &rbyd, rbyd.block, NULL) => 0;
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 1, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 1, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 2, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 2, 0);

    // split the other direction
    //          >b
    //    =>  .-'|
    // 2      2  1
    rbyd = rbyd_init;
    lfs_bd_erase(&lfs, rbyd.block) => 0;
    lfs_rbyd_commit(&lfs, &rbyd,
            LFS_MKRATTR(UATTR, 2, 0, &(uint32_t){0xbbbbbbbb}, 4,
            LFS_MKRATTR(UATTR, 1, 0, &(uint32_t){0xaaaaaaaa}, 4, NULL))) => 0;

    lfs_rbyd_fetch(&lfs, &rbyd, rbyd.block, NULL) => 0;
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 1, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 1, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 2, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 2, 0);
'''

[cases.test_rbyd_bflips]
in = 'lfs.c'
code = '''
    lfs_t lfs;
    lfs_init(&lfs, cfg) => 0;

    lfs_rbyd_t rbyd_init = {
        .block = 0,
        .trunk = 0,
        .noff = 0,
        .rev = 1,
        .crc = 0,
        .count = 0,
        .erased = true,
    };
    lfs_rbyd_t rbyd;
    lfs_off_t off;
    lfs_size_t size;

    // ignore a black edge
    //   <b           <b
    // .-'|  =>  .----'|
    // 1  2      1  2  2
    rbyd = rbyd_init;
    lfs_bd_erase(&lfs, rbyd.block) => 0;
    lfs_rbyd_commit(&lfs, &rbyd,
            LFS_MKRATTR(UATTR, 1, 0, &(uint32_t){0xaaaaaaaa}, 4,
            LFS_MKRATTR(UATTR, 2, 0, &(uint32_t){0xbbbbbbbb}, 4,
            LFS_MKRATTR(UATTR, 2, 0, &(uint32_t){0xbbbbbbbb}, 4, NULL)))) => 0;

    lfs_rbyd_fetch(&lfs, &rbyd, rbyd.block, NULL) => 0;
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 1, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 1, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 2, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 2, 0);

    // flip a black edge
    //   <b           >b
    // .-'|  =>     .-'|
    // 1  2      1  2  1
    rbyd = rbyd_init;
    lfs_bd_erase(&lfs, rbyd.block) => 0;
    lfs_rbyd_commit(&lfs, &rbyd,
            LFS_MKRATTR(UATTR, 1, 0, &(uint32_t){0xaaaaaaaa}, 4,
            LFS_MKRATTR(UATTR, 2, 0, &(uint32_t){0xbbbbbbbb}, 4,
            LFS_MKRATTR(UATTR, 1, 0, &(uint32_t){0xaaaaaaaa}, 4, NULL)))) => 0;

    lfs_rbyd_fetch(&lfs, &rbyd, rbyd.block, NULL) => 0;
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 1, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 1, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 2, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 2, 0);
'''

[cases.test_rbyd_trifoliate]
in = 'lfs.c'
code = '''
    lfs_t lfs;
    lfs_init(&lfs, cfg) => 0;

    lfs_rbyd_t rbyd_init = {
        .block = 0,
        .trunk = 0,
        .noff = 0,
        .rev = 1,
        .crc = 0,
        .count = 0,
        .erased = true,
    };
    lfs_rbyd_t rbyd;
    lfs_off_t off;
    lfs_size_t size;

    // ignore a black edge
    //                <r
    //           .----'|
    //   <b  =>  |    <b
    // .-'|      |  .-'|
    // 1  2      1  2  3
    rbyd = rbyd_init;
    lfs_bd_erase(&lfs, rbyd.block) => 0;
    lfs_rbyd_commit(&lfs, &rbyd,
            LFS_MKRATTR(UATTR, 1, 0, &(uint32_t){0xaaaaaaaa}, 4,
            LFS_MKRATTR(UATTR, 2, 0, &(uint32_t){0xbbbbbbbb}, 4,
            LFS_MKRATTR(UATTR, 3, 0, &(uint32_t){0xcccccccc}, 4, NULL)))) => 0;

    lfs_rbyd_fetch(&lfs, &rbyd, rbyd.block, NULL) => 0;
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 1, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 1, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 2, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 2, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 3, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 3, 0);

    // flip a black edge
    //                >r
    //              .-'|
    //   <b  =>     | >b
    // .-'|      .--|-'|
    // 2  3      2  3  1
    rbyd = rbyd_init;
    lfs_bd_erase(&lfs, rbyd.block) => 0;
    lfs_rbyd_commit(&lfs, &rbyd,
            LFS_MKRATTR(UATTR, 2, 0, &(uint32_t){0xbbbbbbbb}, 4,
            LFS_MKRATTR(UATTR, 3, 0, &(uint32_t){0xcccccccc}, 4,
            LFS_MKRATTR(UATTR, 1, 0, &(uint32_t){0xaaaaaaaa}, 4, NULL)))) => 0;

    lfs_rbyd_fetch(&lfs, &rbyd, rbyd.block, NULL) => 0;
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 1, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 1, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 2, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 2, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 3, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 3, 0);
'''


[cases.test_rbyd_rflips]
in = 'lfs.c'
code = '''
    lfs_t lfs;
    lfs_init(&lfs, cfg) => 0;

    lfs_rbyd_t rbyd_init = {
        .block = 0,
        .trunk = 0,
        .noff = 0,
        .rev = 1,
        .crc = 0,
        .count = 0,
        .erased = true,
    };
    lfs_rbyd_t rbyd;
    lfs_off_t off;
    lfs_size_t size;

    // ignore a red edge and black edge
    //      <r              <r
    // .----'|      .-------'|
    // |    <b  =>  |       <b
    // |  .-'|      |  .----'|
    // 1  2  3      1  2  3  3
    rbyd = rbyd_init;
    lfs_bd_erase(&lfs, rbyd.block) => 0;
    lfs_rbyd_commit(&lfs, &rbyd,
            LFS_MKRATTR(UATTR, 1, 0, &(uint32_t){0xaaaaaaaa}, 4,
            LFS_MKRATTR(UATTR, 2, 0, &(uint32_t){0xbbbbbbbb}, 4,
            LFS_MKRATTR(UATTR, 3, 0, &(uint32_t){0xcccccccc}, 4,
            LFS_MKRATTR(UATTR, 3, 0, &(uint32_t){0xcccccccc}, 4, NULL))))) => 0;

    lfs_rbyd_fetch(&lfs, &rbyd, rbyd.block, NULL) => 0;
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 1, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 1, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 2, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 2, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 3, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 3, 0);

    // ignore a red edge, flip a black edge
    //      <r              <r
    // .----'|      .-------'|
    // |    <b  =>  |       >b
    // |  .-'|      |     .-'|
    // 1  2  3      1  2  3  2
    rbyd = rbyd_init;
    lfs_bd_erase(&lfs, rbyd.block) => 0;
    lfs_rbyd_commit(&lfs, &rbyd,
            LFS_MKRATTR(UATTR, 1, 0, &(uint32_t){0xaaaaaaaa}, 4,
            LFS_MKRATTR(UATTR, 2, 0, &(uint32_t){0xbbbbbbbb}, 4,
            LFS_MKRATTR(UATTR, 3, 0, &(uint32_t){0xcccccccc}, 4,
            LFS_MKRATTR(UATTR, 2, 0, &(uint32_t){0xbbbbbbbb}, 4, NULL))))) => 0;

    lfs_rbyd_fetch(&lfs, &rbyd, rbyd.block, NULL) => 0;
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 1, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 1, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 2, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 2, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 3, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 3, 0);

    // flip a red edge and black edge
    //      <r              >r
    // .----'|            .-'|
    // |    <b  =>        | >b
    // |  .-'|         .--|-'|
    // 1  2  3      1  2  3  1
    rbyd = rbyd_init;
    lfs_bd_erase(&lfs, rbyd.block) => 0;
    lfs_rbyd_commit(&lfs, &rbyd,
            LFS_MKRATTR(UATTR, 1, 0, &(uint32_t){0xaaaaaaaa}, 4,
            LFS_MKRATTR(UATTR, 2, 0, &(uint32_t){0xbbbbbbbb}, 4,
            LFS_MKRATTR(UATTR, 3, 0, &(uint32_t){0xcccccccc}, 4,
            LFS_MKRATTR(UATTR, 1, 0, &(uint32_t){0xaaaaaaaa}, 4, NULL))))) => 0;

    lfs_rbyd_fetch(&lfs, &rbyd, rbyd.block, NULL) => 0;
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 1, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 1, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 2, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 2, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 3, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 3, 0);

    // flip a red edge, ignore a black edge
    //      <r              >r
    //    .-'|      .-------'|
    //    | >b  =>  |       >b
    // .--|-'|      |     .-'|
    // 3  1  2      3  1  2  1
    rbyd = rbyd_init;
    lfs_bd_erase(&lfs, rbyd.block) => 0;
    lfs_rbyd_commit(&lfs, &rbyd,
            LFS_MKRATTR(UATTR, 3, 0, &(uint32_t){0xcccccccc}, 4,
            LFS_MKRATTR(UATTR, 1, 0, &(uint32_t){0xaaaaaaaa}, 4,
            LFS_MKRATTR(UATTR, 2, 0, &(uint32_t){0xbbbbbbbb}, 4,
            LFS_MKRATTR(UATTR, 1, 0, &(uint32_t){0xaaaaaaaa}, 4, NULL))))) => 0;

    lfs_rbyd_fetch(&lfs, &rbyd, rbyd.block, NULL) => 0;
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 1, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 1, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 2, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 2, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 3, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 3, 0);
'''

[cases.test_rbyd_quadrifoliate]
in = 'lfs.c'
code = '''
    lfs_t lfs;
    lfs_init(&lfs, cfg) => 0;

    lfs_rbyd_t rbyd_init = {
        .block = 0,
        .trunk = 0,
        .noff = 0,
        .rev = 1,
        .crc = 0,
        .count = 0,
        .erased = true,
    };
    lfs_rbyd_t rbyd;
    lfs_off_t off;
    lfs_size_t size;

    // ignore a red edge and black edge
    //                      <y
    //              .-------'|
    //      <r      |       <r
    // .----'|  =>  |  .----'|
    // |    <b      |  |    <b
    // |  .-'|      |  |  .-'|
    // 1  2  3      1  2  3  4
    rbyd = rbyd_init;
    lfs_bd_erase(&lfs, rbyd.block) => 0;
    lfs_rbyd_commit(&lfs, &rbyd,
            LFS_MKRATTR(UATTR, 1, 0, &(uint32_t){0xaaaaaaaa}, 4,
            LFS_MKRATTR(UATTR, 2, 0, &(uint32_t){0xbbbbbbbb}, 4,
            LFS_MKRATTR(UATTR, 3, 0, &(uint32_t){0xcccccccc}, 4,
            LFS_MKRATTR(UATTR, 4, 0, &(uint32_t){0xdddddddd}, 4, NULL))))) => 0;

    lfs_rbyd_fetch(&lfs, &rbyd, rbyd.block, NULL) => 0;
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 1, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 1, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 2, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 2, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 3, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 3, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 4, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 4, 0);

    // ignore a red edge, flip a black edge
    //                      <y              >y
    //              .-------'|            .-'|
    //      <r      |       >r            | >r
    // .----'|  =>  |     .-'|  =>     .--|-'|
    // |    <b      |     | >b         |  | <b
    // |  .-'|      |  .--|-'|      .--|--|-'|
    // 1  3  4      1  3  4  2      1  3  4  2
    rbyd = rbyd_init;
    lfs_bd_erase(&lfs, rbyd.block) => 0;
    lfs_rbyd_commit(&lfs, &rbyd,
            LFS_MKRATTR(UATTR, 1, 0, &(uint32_t){0xaaaaaaaa}, 4,
            LFS_MKRATTR(UATTR, 3, 0, &(uint32_t){0xcccccccc}, 4,
            LFS_MKRATTR(UATTR, 4, 0, &(uint32_t){0xdddddddd}, 4,
            LFS_MKRATTR(UATTR, 2, 0, &(uint32_t){0xbbbbbbbb}, 4, NULL))))) => 0;

    lfs_rbyd_fetch(&lfs, &rbyd, rbyd.block, NULL) => 0;
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 1, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 1, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 2, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 2, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 3, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 3, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 4, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 4, 0);

    // flip a red edge and black edge
    //                      >y
    //                    .-'|
    //      <r            | >b
    // .----'|  =>     .--|-'|
    // |    <b         |  | >b
    // |  .-'|      .--|--|-'|
    // 2  3  4      2  3  4  1
    rbyd = rbyd_init;
    lfs_bd_erase(&lfs, rbyd.block) => 0;
    lfs_rbyd_commit(&lfs, &rbyd,
            LFS_MKRATTR(UATTR, 2, 0, &(uint32_t){0xbbbbbbbb}, 4,
            LFS_MKRATTR(UATTR, 3, 0, &(uint32_t){0xcccccccc}, 4,
            LFS_MKRATTR(UATTR, 4, 0, &(uint32_t){0xdddddddd}, 4,
            LFS_MKRATTR(UATTR, 1, 0, &(uint32_t){0xaaaaaaaa}, 4, NULL))))) => 0;

    lfs_rbyd_fetch(&lfs, &rbyd, rbyd.block, NULL) => 0;
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 1, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 1, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 2, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 2, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 3, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 3, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 4, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 4, 0);

    // flip a red edge, ignore a black edge
    //                      >y
    //              .-------'|
    //      <r      |       >r
    //    .-'|  =>  |     .-'|
    //    | >b      |     | <b
    // .--|-'|      |  .--|-'|
    // 4  2  3      4  2  3  1
    rbyd = rbyd_init;
    lfs_bd_erase(&lfs, rbyd.block) => 0;
    lfs_rbyd_commit(&lfs, &rbyd,
            LFS_MKRATTR(UATTR, 4, 0, &(uint32_t){0xdddddddd}, 4,
            LFS_MKRATTR(UATTR, 2, 0, &(uint32_t){0xbbbbbbbb}, 4,
            LFS_MKRATTR(UATTR, 3, 0, &(uint32_t){0xcccccccc}, 4,
            LFS_MKRATTR(UATTR, 1, 0, &(uint32_t){0xaaaaaaaa}, 4, NULL))))) => 0;

    lfs_rbyd_fetch(&lfs, &rbyd, rbyd.block, NULL) => 0;
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 1, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 1, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 2, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 2, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 3, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 3, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 4, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 4, 0);
'''

[cases.test_rbyd_rotations]
in = 'lfs.c'
code = '''
    lfs_t lfs;
    lfs_init(&lfs, cfg) => 0;

    lfs_rbyd_t rbyd_init = {
        .block = 0,
        .trunk = 0,
        .noff = 0,
        .rev = 1,
        .crc = 0,
        .count = 0,
        .erased = true,
    };
    lfs_rbyd_t rbyd;
    lfs_off_t off;
    lfs_size_t size;

    // all three the same
    //                      <y
    //              .-------'|
    //      <r      |       <r
    // .----'|  =>  |  .----'|
    // |    <b      |  |    <b
    // |  .-'|      |  |  .-'|
    // 1  2  3      1  2  3  4
    rbyd = rbyd_init;
    lfs_bd_erase(&lfs, rbyd.block) => 0;
    lfs_rbyd_commit(&lfs, &rbyd,
            LFS_MKRATTR(UATTR, 1, 0, &(uint32_t){0xaaaaaaaa}, 4,
            LFS_MKRATTR(UATTR, 2, 0, &(uint32_t){0xbbbbbbbb}, 4,
            LFS_MKRATTR(UATTR, 3, 0, &(uint32_t){0xcccccccc}, 4,
            LFS_MKRATTR(UATTR, 4, 0, &(uint32_t){0xdddddddd}, 4, NULL))))) => 0;

    lfs_rbyd_fetch(&lfs, &rbyd, rbyd.block, NULL) => 0;
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 1, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 1, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 2, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 2, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 3, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 3, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 4, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 4, 0);

    // yellow and red alt the same
    //                      <y
    //              .-------'|
    //      <r      |       <r
    // .----'|  =>  |  .----'|
    // |    <b      |  |    >b
    // |  .-'|      |  |  .-'|
    // 1  2  4      1  2  4  3
    rbyd = rbyd_init;
    lfs_bd_erase(&lfs, rbyd.block) => 0;
    lfs_rbyd_commit(&lfs, &rbyd,
            LFS_MKRATTR(UATTR, 1, 0, &(uint32_t){0xaaaaaaaa}, 4,
            LFS_MKRATTR(UATTR, 2, 0, &(uint32_t){0xbbbbbbbb}, 4,
            LFS_MKRATTR(UATTR, 4, 0, &(uint32_t){0xdddddddd}, 4,
            LFS_MKRATTR(UATTR, 3, 0, &(uint32_t){0xcccccccc}, 4, NULL))))) => 0;

    lfs_rbyd_fetch(&lfs, &rbyd, rbyd.block, NULL) => 0;
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 1, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 1, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 2, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 2, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 3, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 3, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 4, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 4, 0);

    // yellow and black alt the same
    //                      <y              <y
    //              .-------'|      .-------'|
    //      <r      |       >r      |       <r
    // .----'|  =>  |  .----'|  =>  |     .-'|
    // |    >b      |  |    <b      |     | >b
    // |  .-'|      |  |  .-'|      |  .--|-'|
    // 1  4  2      1  4  2  3      1  4  2  3
    rbyd = rbyd_init;
    lfs_bd_erase(&lfs, rbyd.block) => 0;
    lfs_rbyd_commit(&lfs, &rbyd,
            LFS_MKRATTR(UATTR, 1, 0, &(uint32_t){0xaaaaaaaa}, 4,
            LFS_MKRATTR(UATTR, 4, 0, &(uint32_t){0xdddddddd}, 4,
            LFS_MKRATTR(UATTR, 2, 0, &(uint32_t){0xbbbbbbbb}, 4,
            LFS_MKRATTR(UATTR, 3, 0, &(uint32_t){0xcccccccc}, 4, NULL))))) => 0;

    lfs_rbyd_fetch(&lfs, &rbyd, rbyd.block, NULL) => 0;
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 1, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 1, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 2, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 2, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 3, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 3, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 4, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 4, 0);

    // red and black alt the same
    //                      >y              <y
    //              .-------'|         .----'|
    //      >r      |       <r         |    <r
    // .----'|  =>  |  .----'|  =>     |  .-'|
    // |    <b      |  |    <b         |  | >b
    // |  .-'|      |  |  .-'|      .--|--|-'|
    // 4  1  2      4  1  2  3      4  1  2  3
    rbyd = rbyd_init;
    lfs_bd_erase(&lfs, rbyd.block) => 0;
    lfs_rbyd_commit(&lfs, &rbyd,
            LFS_MKRATTR(UATTR, 1, 0, &(uint32_t){0xaaaaaaaa}, 4,
            LFS_MKRATTR(UATTR, 4, 0, &(uint32_t){0xdddddddd}, 4,
            LFS_MKRATTR(UATTR, 2, 0, &(uint32_t){0xbbbbbbbb}, 4,
            LFS_MKRATTR(UATTR, 3, 0, &(uint32_t){0xcccccccc}, 4, NULL))))) => 0;

    lfs_rbyd_fetch(&lfs, &rbyd, rbyd.block, NULL) => 0;
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 1, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 1, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 2, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 2, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 3, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 3, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 4, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 4, 0);
'''

[cases.test_rbyd_ysplits]
in = 'lfs.c'
code = '''
    lfs_t lfs;
    lfs_init(&lfs, cfg) => 0;

    lfs_rbyd_t rbyd_init = {
        .block = 0,
        .trunk = 0,
        .noff = 0,
        .rev = 1,
        .crc = 0,
        .count = 0,
        .erased = true,
    };
    lfs_rbyd_t rbyd;
    lfs_off_t off;
    lfs_size_t size;

    // split a yellow triple, not taking any alt
    //                            <b
    //                          .-'|
    //         <y              <y  |
    // .-------'|      .-------'|  |
    // |       <r  =>  |       <r  |
    // |  .----'|      |  .----'   |
    // |  |    <b      |  |       <b
    // |  |  .-'|      |  |  .----'|
    // 1  2  3  4      1  2  3  4  4
    rbyd = rbyd_init;
    lfs_bd_erase(&lfs, rbyd.block) => 0;
    lfs_rbyd_commit(&lfs, &rbyd,
            LFS_MKRATTR(UATTR, 1, 0, &(uint32_t){0xaaaaaaaa}, 4,
            LFS_MKRATTR(UATTR, 2, 0, &(uint32_t){0xbbbbbbbb}, 4,
            LFS_MKRATTR(UATTR, 3, 0, &(uint32_t){0xcccccccc}, 4,
            LFS_MKRATTR(UATTR, 4, 0, &(uint32_t){0xdddddddd}, 4,
            LFS_MKRATTR(UATTR, 4, 0, &(uint32_t){0xdddddddd}, 4, NULL)))))) => 0;

    lfs_rbyd_fetch(&lfs, &rbyd, rbyd.block, NULL) => 0;
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 1, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 1, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 2, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 2, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 3, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 3, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 4, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 4, 0);

    // split a yellow triple, taking the black alt
    //                            <b
    //                          .-'|
    //         <y              <y  |
    // .-------'|      .-------'|  |
    // |       <r  =>  |       <r  |
    // |  .----'|      |  .----'   |
    // |  |    <b      |  |       >b
    // |  |  .-'|      |  |     .-'|
    // 1  2  3  4      1  2  3  4  3
    rbyd = rbyd_init;
    lfs_bd_erase(&lfs, rbyd.block) => 0;
    lfs_rbyd_commit(&lfs, &rbyd,
            LFS_MKRATTR(UATTR, 1, 0, &(uint32_t){0xaaaaaaaa}, 4,
            LFS_MKRATTR(UATTR, 2, 0, &(uint32_t){0xbbbbbbbb}, 4,
            LFS_MKRATTR(UATTR, 3, 0, &(uint32_t){0xcccccccc}, 4,
            LFS_MKRATTR(UATTR, 4, 0, &(uint32_t){0xdddddddd}, 4,
            LFS_MKRATTR(UATTR, 3, 0, &(uint32_t){0xcccccccc}, 4, NULL)))))) => 0;

    lfs_rbyd_fetch(&lfs, &rbyd, rbyd.block, NULL) => 0;
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 1, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 1, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 2, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 2, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 3, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 3, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 4, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 4, 0);

    // split a yellow triple, taking the red alt
    //         <y                 >b
    // .-------'|               .-'|
    // |       <r               | <b
    // |  .----'|  =>  .--------|-'|
    // |  |    <b      |       <b  |
    // |  |  .-'|      |     .-'|  |
    // 1  2  3  4      1  2  3  4  2
    rbyd = rbyd_init;
    lfs_bd_erase(&lfs, rbyd.block) => 0;
    lfs_rbyd_commit(&lfs, &rbyd,
            LFS_MKRATTR(UATTR, 1, 0, &(uint32_t){0xaaaaaaaa}, 4,
            LFS_MKRATTR(UATTR, 2, 0, &(uint32_t){0xbbbbbbbb}, 4,
            LFS_MKRATTR(UATTR, 3, 0, &(uint32_t){0xcccccccc}, 4,
            LFS_MKRATTR(UATTR, 4, 0, &(uint32_t){0xdddddddd}, 4,
            LFS_MKRATTR(UATTR, 2, 0, &(uint32_t){0xbbbbbbbb}, 4, NULL)))))) => 0;

    lfs_rbyd_fetch(&lfs, &rbyd, rbyd.block, NULL) => 0;
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 1, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 1, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 2, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 2, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 3, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 3, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 4, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 4, 0);

    // split a yellow triple, taking the yellow alt
    //         <y                 >b
    // .-------'|               .-'|
    // |       <r               | >b
    // |  .----'|  =>     .-----|-'|
    // |  |    <b         |    <b  |
    // |  |  .-'|         |  .-'|  |
    // 1  2  3  4      1  2  3  4  1
    rbyd = rbyd_init;
    lfs_bd_erase(&lfs, rbyd.block) => 0;
    lfs_rbyd_commit(&lfs, &rbyd,
            LFS_MKRATTR(UATTR, 1, 0, &(uint32_t){0xaaaaaaaa}, 4,
            LFS_MKRATTR(UATTR, 2, 0, &(uint32_t){0xbbbbbbbb}, 4,
            LFS_MKRATTR(UATTR, 3, 0, &(uint32_t){0xcccccccc}, 4,
            LFS_MKRATTR(UATTR, 4, 0, &(uint32_t){0xdddddddd}, 4,
            LFS_MKRATTR(UATTR, 1, 0, &(uint32_t){0xaaaaaaaa}, 4, NULL)))))) => 0;

    lfs_rbyd_fetch(&lfs, &rbyd, rbyd.block, NULL) => 0;
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 1, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 1, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 2, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 2, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 3, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 3, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 4, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 4, 0);
'''

[cases.test_rbyd_quintifoliate]
in = 'lfs.c'
code = '''
    lfs_t lfs;
    lfs_init(&lfs, cfg) => 0;

    lfs_rbyd_t rbyd_init = {
        .block = 0,
        .trunk = 0,
        .noff = 0,
        .rev = 1,
        .crc = 0,
        .count = 0,
        .erased = true,
    };
    lfs_rbyd_t rbyd;
    lfs_off_t off;
    lfs_size_t size;

    // split a yellow triple, not taking any alt
    //                            <b
    //                          .-'|
    //                         <y  |
    //                 .-------'|  |
    //         <y      |       <r  |
    // .-------'|  =>  |  .----'   |
    // |       <r      |  |       <r
    // |  .----'|      |  |  .----'|
    // |  |    <b      |  |  |    <b
    // |  |  .-'|      |  |  |  .-'|
    // 1  2  3  4      1  2  3  4  5
    rbyd = rbyd_init;
    lfs_bd_erase(&lfs, rbyd.block) => 0;
    lfs_rbyd_commit(&lfs, &rbyd,
            LFS_MKRATTR(UATTR, 1, 0, &(uint32_t){0xaaaaaaaa}, 4,
            LFS_MKRATTR(UATTR, 2, 0, &(uint32_t){0xbbbbbbbb}, 4,
            LFS_MKRATTR(UATTR, 3, 0, &(uint32_t){0xcccccccc}, 4,
            LFS_MKRATTR(UATTR, 4, 0, &(uint32_t){0xdddddddd}, 4,
            LFS_MKRATTR(UATTR, 5, 0, &(uint32_t){0xeeeeeeee}, 4, NULL)))))) => 0;

    lfs_rbyd_fetch(&lfs, &rbyd, rbyd.block, NULL) => 0;
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 1, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 1, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 2, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 2, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 3, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 3, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 4, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 4, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 5, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 5, 0);

    // split a yellow triple, taking the black alt
    //                            <b
    //                          .-'|
    //                         <y  |
    //                 .-------'|  |
    //         <y      |       <r  |
    // .-------'|  =>  |  .----'   |
    // |       <r      |  |       >r
    // |  .----'|      |  |     .-'|
    // |  |    <b      |  |     | >b
    // |  |  .-'|      |  |  .--|-'|
    // 1  2  4  5      1  2  4  5  3
    rbyd = rbyd_init;
    lfs_bd_erase(&lfs, rbyd.block) => 0;
    lfs_rbyd_commit(&lfs, &rbyd,
            LFS_MKRATTR(UATTR, 1, 0, &(uint32_t){0xaaaaaaaa}, 4,
            LFS_MKRATTR(UATTR, 2, 0, &(uint32_t){0xbbbbbbbb}, 4,
            LFS_MKRATTR(UATTR, 4, 0, &(uint32_t){0xdddddddd}, 4,
            LFS_MKRATTR(UATTR, 5, 0, &(uint32_t){0xeeeeeeee}, 4,
            LFS_MKRATTR(UATTR, 3, 0, &(uint32_t){0xcccccccc}, 4, NULL)))))) => 0;

    lfs_rbyd_fetch(&lfs, &rbyd, rbyd.block, NULL) => 0;
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 1, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 1, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 2, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 2, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 3, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 3, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 4, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 4, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 5, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 5, 0);

    // split a yellow triple, taking the red alt
    //                            >b
    //                          .-'|
    //         <y               | <r
    // .-------'|      .--------|-'|
    // |       <r      |        | >b
    // |  .----'|  =>  |  .-----|-'|
    // |  |    <b      |  |    <b  |
    // |  |  .-'|      |  |  .-'|  |
    // 1  3  4  5      1  3  4  5  2
    rbyd = rbyd_init;
    lfs_bd_erase(&lfs, rbyd.block) => 0;
    lfs_rbyd_commit(&lfs, &rbyd,
            LFS_MKRATTR(UATTR, 1, 0, &(uint32_t){0xaaaaaaaa}, 4,
            LFS_MKRATTR(UATTR, 3, 0, &(uint32_t){0xcccccccc}, 4,
            LFS_MKRATTR(UATTR, 4, 0, &(uint32_t){0xdddddddd}, 4,
            LFS_MKRATTR(UATTR, 5, 0, &(uint32_t){0xeeeeeeee}, 4,
            LFS_MKRATTR(UATTR, 2, 0, &(uint32_t){0xbbbbbbbb}, 4, NULL)))))) => 0;

    lfs_rbyd_fetch(&lfs, &rbyd, rbyd.block, NULL) => 0;
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 1, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 1, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 2, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 2, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 3, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 3, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 4, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 4, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 5, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 5, 0);

    // split a yellow triple, taking the yellow alt
    //                            >b
    //                          .-'|
    //         <y               | >r
    // .-------'|         .-----|-'|
    // |       <r         |     | >b
    // |  .----'|  =>  .--|-----|-'|
    // |  |    <b      |  |    <b  |
    // |  |  .-'|      |  |  .-'|  |
    // 2  3  4  5      2  3  4  5  1
    rbyd = rbyd_init;
    lfs_bd_erase(&lfs, rbyd.block) => 0;
    lfs_rbyd_commit(&lfs, &rbyd,
            LFS_MKRATTR(UATTR, 2, 0, &(uint32_t){0xbbbbbbbb}, 4,
            LFS_MKRATTR(UATTR, 3, 0, &(uint32_t){0xcccccccc}, 4,
            LFS_MKRATTR(UATTR, 4, 0, &(uint32_t){0xdddddddd}, 4,
            LFS_MKRATTR(UATTR, 5, 0, &(uint32_t){0xeeeeeeee}, 4,
            LFS_MKRATTR(UATTR, 1, 0, &(uint32_t){0xaaaaaaaa}, 4, NULL)))))) => 0;

    lfs_rbyd_fetch(&lfs, &rbyd, rbyd.block, NULL) => 0;
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 1, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 1, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 2, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 2, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 3, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 3, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 4, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 4, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 5, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 5, 0);
'''

[cases.test_rbyd_prunes]
in = 'lfs.c'
code = '''
    lfs_t lfs;
    lfs_init(&lfs, cfg) => 0;

    lfs_rbyd_t rbyd_init = {
        .block = 0,
        .trunk = 0,
        .noff = 0,
        .rev = 1,
        .crc = 0,
        .count = 0,
        .erased = true,
    };
    lfs_rbyd_t rbyd;
    lfs_off_t off;
    lfs_size_t size;

    // don't prune
    //            <b                    <b
    //          .-'|               .----'|
    //         <y  |              <y     |
    // .-------'|  |      .-------'|     |
    // |       <r  |      |       <r     |
    // |  .----'   |  =>  |  .----'      |
    // |  |       <r      |  |          <r
    // |  |  .----'|      |  |  .-------'|
    // |  |  |    <b      |  |  |       <b
    // |  |  |  .-'|      |  |  |  .----'|
    // 1  2  3  4  5      1  2  3  4  5  5
    rbyd = rbyd_init;
    lfs_bd_erase(&lfs, rbyd.block) => 0;
    lfs_rbyd_commit(&lfs, &rbyd,
            LFS_MKRATTR(UATTR, 1, 0, &(uint32_t){0xaaaaaaaa}, 4,
            LFS_MKRATTR(UATTR, 2, 0, &(uint32_t){0xbbbbbbbb}, 4,
            LFS_MKRATTR(UATTR, 3, 0, &(uint32_t){0xcccccccc}, 4,
            LFS_MKRATTR(UATTR, 4, 0, &(uint32_t){0xdddddddd}, 4,
            LFS_MKRATTR(UATTR, 5, 0, &(uint32_t){0xeeeeeeee}, 4,
            LFS_MKRATTR(UATTR, 5, 0, &(uint32_t){0xeeeeeeee}, 4, NULL))))))) => 0;

    lfs_rbyd_fetch(&lfs, &rbyd, rbyd.block, NULL) => 0;
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 1, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 1, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 2, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 2, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 3, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 3, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 4, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 4, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 5, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 5, 0);

    // prune by taking a red alt
    //            <b
    //          .-'|
    //         <y  |                    >b
    // .-------'|  |                  .-'|
    // |       <r  |                  | <b
    // |  .----'   |  =>  .-----------|-'|
    // |  |       <r      |          <r  |
    // |  |  .----'|      |     .----'|  |
    // |  |  |    <b      |     |    <b  |
    // |  |  |  .-'|      |     |  .-'|  |
    // 1  2  3  4  5      1  2  3  4  5  2
    rbyd = rbyd_init;
    lfs_bd_erase(&lfs, rbyd.block) => 0;
    lfs_rbyd_commit(&lfs, &rbyd,
            LFS_MKRATTR(UATTR, 1, 0, &(uint32_t){0xaaaaaaaa}, 4,
            LFS_MKRATTR(UATTR, 2, 0, &(uint32_t){0xbbbbbbbb}, 4,
            LFS_MKRATTR(UATTR, 3, 0, &(uint32_t){0xcccccccc}, 4,
            LFS_MKRATTR(UATTR, 4, 0, &(uint32_t){0xdddddddd}, 4,
            LFS_MKRATTR(UATTR, 5, 0, &(uint32_t){0xeeeeeeee}, 4,
            LFS_MKRATTR(UATTR, 2, 0, &(uint32_t){0xbbbbbbbb}, 4, NULL))))))) => 0;

    lfs_rbyd_fetch(&lfs, &rbyd, rbyd.block, NULL) => 0;
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 1, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 1, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 2, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 2, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 3, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 3, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 4, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 4, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 5, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 5, 0);

    // prune by taking a yellow alt (this needs to prune during the rflip)
    //            <b
    //          .-'|
    //         <y  |                    >b
    // .-------'|  |                  .-'|
    // |       <r  |                  | >b
    // |  .----'   |  =>     .--------|-'|
    // |  |       <r         |       <r  |
    // |  |  .----'|         |  .----'|  |
    // |  |  |    <b         |  |    <b  |
    // |  |  |  .-'|         |  |  .-'|  |
    // 1  2  3  4  5      1  2  3  4  5  1
    rbyd = rbyd_init;
    lfs_bd_erase(&lfs, rbyd.block) => 0;
    lfs_rbyd_commit(&lfs, &rbyd,
            LFS_MKRATTR(UATTR, 1, 0, &(uint32_t){0xaaaaaaaa}, 4,
            LFS_MKRATTR(UATTR, 2, 0, &(uint32_t){0xbbbbbbbb}, 4,
            LFS_MKRATTR(UATTR, 3, 0, &(uint32_t){0xcccccccc}, 4,
            LFS_MKRATTR(UATTR, 4, 0, &(uint32_t){0xdddddddd}, 4,
            LFS_MKRATTR(UATTR, 5, 0, &(uint32_t){0xeeeeeeee}, 4,
            LFS_MKRATTR(UATTR, 1, 0, &(uint32_t){0xaaaaaaaa}, 4, NULL))))))) => 0;

    lfs_rbyd_fetch(&lfs, &rbyd, rbyd.block, NULL) => 0;
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 1, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 1, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 2, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 2, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 3, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 3, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 4, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 4, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 5, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 5, 0);
'''

[cases.test_rbyd_sextifoliate]
in = 'lfs.c'
code = '''
    lfs_t lfs;
    lfs_init(&lfs, cfg) => 0;

    lfs_rbyd_t rbyd_init = {
        .block = 0,
        .trunk = 0,
        .noff = 0,
        .rev = 1,
        .crc = 0,
        .count = 0,
        .erased = true,
    };
    lfs_rbyd_t rbyd;
    lfs_off_t off;
    lfs_size_t size;

    // don't prune
    //                                  <b
    //                             .----'|
    //            <b              <y     |
    //          .-'|      .-------'|     |
    //         <y  |      |       <r     |
    // .-------'|  |      |  .----'      |
    // |       <r  |      |  |          <y
    // |  .----'   |  =>  |  |  .-------'|
    // |  |       <r      |  |  |       <r
    // |  |  .----'|      |  |  |  .----'|
    // |  |  |    <b      |  |  |  |    <b
    // |  |  |  .-'|      |  |  |  |  .-'|
    // 1  2  3  4  5      1  2  3  4  5  6
    rbyd = rbyd_init;
    lfs_bd_erase(&lfs, rbyd.block) => 0;
    lfs_rbyd_commit(&lfs, &rbyd,
            LFS_MKRATTR(UATTR, 1, 0, &(uint32_t){0xaaaaaaaa}, 4,
            LFS_MKRATTR(UATTR, 2, 0, &(uint32_t){0xbbbbbbbb}, 4,
            LFS_MKRATTR(UATTR, 3, 0, &(uint32_t){0xcccccccc}, 4,
            LFS_MKRATTR(UATTR, 4, 0, &(uint32_t){0xdddddddd}, 4,
            LFS_MKRATTR(UATTR, 5, 0, &(uint32_t){0xeeeeeeee}, 4,
            LFS_MKRATTR(UATTR, 6, 0, &(uint32_t){0xffffffff}, 4, NULL))))))) => 0;

    lfs_rbyd_fetch(&lfs, &rbyd, rbyd.block, NULL) => 0;
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 1, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 1, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 2, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 2, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 3, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 3, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 4, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 4, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 5, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 5, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 6, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 6, 0);

    // prune by taking a red alt
    //            <b                    >b
    //          .-'|                  .-'|
    //         <y  |                  | <r
    // .-------'|  |      .-----------|-'|
    // |       <r  |      |           | >b
    // |  .----'   |  =>  |  .--------|-'|
    // |  |       <r      |  |       <r  |
    // |  |  .----'|      |  |  .----'|  |
    // |  |  |    <b      |  |  |    <b  |
    // |  |  |  .-'|      |  |  |  .-'|  |
    // 1  3  4  5  6      1  3  4  5  6  2
    rbyd = rbyd_init;
    lfs_bd_erase(&lfs, rbyd.block) => 0;
    lfs_rbyd_commit(&lfs, &rbyd,
            LFS_MKRATTR(UATTR, 1, 0, &(uint32_t){0xaaaaaaaa}, 4,
            LFS_MKRATTR(UATTR, 3, 0, &(uint32_t){0xcccccccc}, 4,
            LFS_MKRATTR(UATTR, 4, 0, &(uint32_t){0xdddddddd}, 4,
            LFS_MKRATTR(UATTR, 5, 0, &(uint32_t){0xeeeeeeee}, 4,
            LFS_MKRATTR(UATTR, 6, 0, &(uint32_t){0xffffffff}, 4,
            LFS_MKRATTR(UATTR, 2, 0, &(uint32_t){0xbbbbbbbb}, 4, NULL))))))) => 0;

    lfs_rbyd_fetch(&lfs, &rbyd, rbyd.block, NULL) => 0;
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 1, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 1, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 2, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 2, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 3, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 3, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 4, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 4, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 5, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 5, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 6, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 6, 0);

    // prune by taking a yellow alt (this needs to prune during the rflip)
    //            <b                    >b
    //          .-'|                  .-'|
    //         <y  |                  | >r
    // .-------'|  |         .--------|-'|
    // |       <r  |         |        | >b
    // |  .----'   |  =>  .--|--------|-'|
    // |  |       <r      |  |       <r  |
    // |  |  .----'|      |  |  .----'|  |
    // |  |  |    <b      |  |  |    <b  |
    // |  |  |  .-'|      |  |  |  .-'|  |
    // 2  3  4  5  6      2  3  4  5  6  1
    rbyd = rbyd_init;
    lfs_bd_erase(&lfs, rbyd.block) => 0;
    lfs_rbyd_commit(&lfs, &rbyd,
            LFS_MKRATTR(UATTR, 2, 0, &(uint32_t){0xbbbbbbbb}, 4,
            LFS_MKRATTR(UATTR, 3, 0, &(uint32_t){0xcccccccc}, 4,
            LFS_MKRATTR(UATTR, 4, 0, &(uint32_t){0xdddddddd}, 4,
            LFS_MKRATTR(UATTR, 5, 0, &(uint32_t){0xeeeeeeee}, 4,
            LFS_MKRATTR(UATTR, 6, 0, &(uint32_t){0xffffffff}, 4,
            LFS_MKRATTR(UATTR, 1, 0, &(uint32_t){0xaaaaaaaa}, 4, NULL))))))) => 0;

    lfs_rbyd_fetch(&lfs, &rbyd, rbyd.block, NULL) => 0;
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 1, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 1, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 2, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 2, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 3, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 3, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 4, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 4, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 5, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 5, 0);
    lfs_rbyd_lookup(&lfs, &rbyd, LFS_MKRTAG(UATTR, 6, 0), &off, &size)
            => LFS_MKRTAG(UATTR, 6, 0);
'''