test_read_format_7zip_lzma* tests fail with Gentoo "minimal" liblzma/xz-utils

[mgorny]

Gentoo supports building a smaller version of liblzma that doesn't include filters that aren't normally used in .xz files. It is built with the following configure switches:

--enable-encoders=lzma1,lzma2
--enable-decoders=lzma1,lzma2
--enable-match-finders=hc3,hc4,bt4
--enable-checks=crc32,crc64

In particular, it doesn't support delta and executable filters, non-default match finders and sha256 checks.

This causes the following libarchive tests to fail:

  203: test_read_format_7zip_lzma1 (4 failures)
  204: test_read_format_7zip_lzma2 (6 failures)
  206: test_read_format_7zip_lzma2_arm (2 failures)
  208: test_read_format_7zip_lzma2_arm64 (2 failures)

Details:

==> test_read_format_7zip_lzma1.log <==
test_read_format_7zip_lzma1

libarchive/test/test_read_format_7zip.c:666: sizeof(buff) != bytes = archive_read_data(a, buff, sizeof(buff))
      sizeof(buff)=1024 (0x400, 02000)
      bytes = archive_read_data(a, buff, sizeof(buff))=-30 (0xffffffffffffffe2, 01777777777777777777742)
libarchive/test/test_read_format_7zip.c:673: 0 != remaining
      0=0 (0x0, 00)
      remaining=27627 (0x6beb, 065753)
libarchive/test/test_read_format_7zip.c:666: sizeof(buff) != bytes = archive_read_data(a, buff, sizeof(buff))
      sizeof(buff)=1024 (0x400, 02000)
      bytes = archive_read_data(a, buff, sizeof(buff))=-30 (0xffffffffffffffe2, 01777777777777777777742)
libarchive/test/test_read_format_7zip.c:673: 0 != remaining
      0=0 (0x0, 00)
      remaining=27627 (0x6beb, 065753)
libarchive/test/test_read_format_7zip.c:666: Summary: Failed 2 times
libarchive/test/test_read_format_7zip.c:673: Summary: Failed 2 times

==> test_read_format_7zip_lzma2_arm64.log <==
test_read_format_7zip_lzma2_arm64

libarchive/test/test_read_format_7zip.c:1137: sizeof(buff) != archive_read_data(a, buff, sizeof(buff))
      sizeof(buff)=70368 (0x112e0, 0211340)
      archive_read_data(a, buff, sizeof(buff))=-30 (0xffffffffffffffe2, 01777777777777777777742)
libarchive/test/test_read_format_7zip.c:1139: computed_crc != expected_crc
      computed_crc=636228993 (0x25ec1581, 04573012601)
      expected_crc=3734492564 (0xde97d594, 033645752624)

==> test_read_format_7zip_lzma2_arm.log <==
test_read_format_7zip_lzma2_arm

libarchive/test/test_read_format_7zip.c:1064: sizeof(buff) != archive_read_data(a, buff, sizeof(buff))
      sizeof(buff)=7804 (0x1e7c, 017174)
      archive_read_data(a, buff, sizeof(buff))=-30 (0xffffffffffffffe2, 01777777777777777777742)
libarchive/test/test_read_format_7zip.c:1066: computed_crc != expected_crc
      computed_crc=4146314219 (0xf723bbeb, 036710735753)
      expected_crc=895403233 (0x355ec4e1, 06527542341)

==> test_read_format_7zip_lzma2.log <==
test_read_format_7zip_lzma2

libarchive/test/test_read_format_7zip.c:722: sizeof(buff) != bytes = archive_read_data(a, buff, sizeof(buff))
      sizeof(buff)=1024 (0x400, 02000)
      bytes = archive_read_data(a, buff, sizeof(buff))=-30 (0xffffffffffffffe2, 01777777777777777777742)
libarchive/test/test_read_format_7zip.c:729: 0 != remaining
      0=0 (0x0, 00)
      remaining=27328 (0x6ac0, 065300)
libarchive/test/test_read_format_7zip.c:666: sizeof(buff) != bytes = archive_read_data(a, buff, sizeof(buff))
      sizeof(buff)=1024 (0x400, 02000)
      bytes = archive_read_data(a, buff, sizeof(buff))=-30 (0xffffffffffffffe2, 01777777777777777777742)
libarchive/test/test_read_format_7zip.c:673: 0 != remaining
      0=0 (0x0, 00)
      remaining=27627 (0x6beb, 065753)
libarchive/test/test_read_format_7zip.c:666: sizeof(buff) != bytes = archive_read_data(a, buff, sizeof(buff))
      sizeof(buff)=1024 (0x400, 02000)
      bytes = archive_read_data(a, buff, sizeof(buff))=-30 (0xffffffffffffffe2, 01777777777777777777742)
libarchive/test/test_read_format_7zip.c:673: 0 != remaining
      0=0 (0x0, 00)
      remaining=27627 (0x6beb, 065753)
libarchive/test/test_read_format_7zip.c:666: Summary: Failed 2 times
libarchive/test/test_read_format_7zip.c:673: Summary: Failed 2 times

While I do realize that such a build of libarchive will not have a fully functional .7z support, could we make these tests skip if liblzma is lacking the necessary filters?