Re: [PATCH] t5310-pack-bitmaps: skip JGit tests with SHA256

["SZEDER Gábor" <szeder.dev@gmail.com>]

On Fri, Nov 13, 2020 at 10:53:07PM +0100, SZEDER Gábor wrote:
> In 't5310-pack-bitmaps.sh' two tests make sure that our pack bitmaps
> are compatible with JGit's bitmaps.  Alas, not even the most recent
> JGit version (5.9.0.202009080501-r) supports SHA256 yet, so when this
> test script is run with GIT_TEST_DEFAULT_HASH=sha256 on a setup with
> JGit installed in PATH, then these two tests fail.

So both of those tests invoke 'jgit gc' which fails with the same
error message in both cases:

  + jgit gc
  fatal: Invalid id: 93b89bd36289ec88dd9db249a48da3e7440e46b94d3a93d98540062bec0e5ac1

This is clearly related to SHA256 (though I think JGit shouldn't even
get as far as looking at object IDs, but should have errored out upon
seeing the unsupported extensions.objectformat=sha256 in the config,
and it's alarming that it didn't).

Now, we do have one more JGit test: "indicate no refs in
standards-compliant empty remote" in 't5512-ls-remote.sh', which fails
with SHA256 as well... but the failure comes from 'git ls-remote':

  + test_expect_code 2 git ls-remote --exit-code git://localhost:5512/empty.git
  fatal: protocol error: unexpected capabilities^{}
  test_expect_code: command exited with 128, we wanted 2 git ls-remote --exit-code git://localhost:5512/empty.git

This doesn't at all look like an error related to SHA256, but I'm not
up to speed with SHA256-specific protocol stuff...  so I'm hesitant to
simply protect this test with the SHA1 prereq as well.