Multiple tests fail when zlib implementation is zlib-ng

[laumann]

Gentoo Linux has recently implemented the option to provide zlib-ng as an alternative zlib implementation, and it turns out some of the tests for openjpeg fail when zlib-ng is used. The issue in Gentoo is here: https://bugs.gentoo.org/965571

Here's the output (full logs are attached on the Gentoo bug):

98% tests passed, 31 tests failed out of 1579

Total Test time (real) =  11.21 sec

The following tests FAILED:
        1199 - NR-DEC-p1_04.j2k-124-decode-md5 (Failed)
        1213 - NR-DEC-p1_04.j2k-131-decode-md5 (Failed)
        1215 - NR-DEC-p1_04.j2k-132-decode-md5 (Failed)
        1231 - NR-DEC-p1_04.j2k-140-decode-md5 (Failed)
        1235 - NR-DEC-p1_06.j2k-142-decode-md5 (Failed)
        1237 - NR-DEC-p1_06.j2k-143-decode-md5 (Failed)
        1249 - NR-DEC-p1_06.j2k-149-decode-md5 (Failed)
        1281 - NR-DEC-p0_04.j2k-166-decode-md5 (Failed)
        1283 - NR-DEC-p0_04.j2k-167-decode-md5 (Failed)
        1285 - NR-DEC-p0_04.j2k-168-decode-md5 (Failed)
        1289 - NR-DEC-p0_04.j2k-170-decode-md5 (Failed)
        1379 - NR-DEC-a1_mono.j2c-215-decode-md5 (Failed)
        1381 - NR-DEC-a1_mono.j2c-216-decode-md5 (Failed)
        1383 - NR-DEC-a1_mono.j2c-217-decode-md5 (Failed)
        1395 - NR-DEC-a1_mono.j2c-223-decode-md5 (Failed)
        1433 - NR-DEC-basn6a08.jp2-242-decode-md5 (Failed)
        1437 - NR-DEC-basn6a08.jp2-244-decode-md5 (Failed)
        1439 - NR-DEC-basn6a08.jp2-245-decode-md5 (Failed)
        1441 - NR-DEC-basn6a08.jp2-246-decode-md5 (Failed)
        1445 - NR-DEC-basn6a08.jp2-248-decode-md5 (Failed)
        1449 - NR-DEC-basn6a08.jp2-250-decode-md5 (Failed)
        1536 - NR-DEC-file1.jp2-298-decode-md5 (Failed)
        1544 - NR-DEC-file1.jp2-302-decode-md5 (Failed)
        1550 - NR-DEC-db11217111510058.jp2-306-decode-md5 (Failed)
        1552 - NR-DEC-tnsot_zero.jp2-307-decode-md5 (Failed)
        1557 - NR-DEC-Bretagne1_ht.j2k-310-decode-md5 (Failed)
        1559 - NR-DEC-Bretagne1_ht_lossy.j2k-311-decode-md5 (Failed)
        1568 - NR-DEC-small_world_non_consecutive_tilepart_tlm.jp2-316-decode-md5 (Failed)
        1570 - NR-DEC-small_world_non_consecutive_tilepart_tlm.jp2-317-decode-md5 (Failed)
        1572 - NR-DEC-small_world_non_consecutive_tilepart_tlm.jp2-318-decode-md5 (Failed)
        1574 - NR-DEC-small_world_non_consecutive_tilepart_tlm.jp2-319-decode-md5 (Failed)

I'd like to figure out if this is an actual problem, or if the tests are just brittle in that they expect a PNG to be output with some exact compressed bytes?

[rouault]

or if the tests are just brittle in that they expect a PNG to be output with some exact compressed bytes?

yes

[laumann]

or if the tests are just brittle in that they expect a PNG to be output with some exact compressed bytes?

yes

Short and sweet, thanks! Would you want the openjpeg tests to be able to handle zlib-ng, or is that not a priority? Either way, I'll probably add a workaround to the Gentoo package to skip tests when the zlib impl is zlib-ng.

[rouault]

I'm not against someone submitted alternate checksum for zlib-ng, provided that the ones from zlib classic are still supported