[Feature] Support extensions.worktreeconfig for repositoryformatversion=1

[Whirlwind]

$ git clone --filter=blob:none git@xxx:xx/xx.git
$ cd xx
$ git worktree add ../worktree
$ cd ../worktree
$ git config extensions.worktreeConfig true

I have a origin repository with --filter=blob:none, and a worktree repository. Then I enable the worktree config in the worktree.

In the libgit2, it could not support the worktree config with filter:

unsupported extension name extensions.worktreeconfig

I check the libgit2:

static int check_valid_extension(const git_config_entry *entry, void *payload)
{
	GIT_UNUSED(payload);

	if (!strcmp(entry->name, "extensions.noop"))
		return 0;

	git_error_set(GIT_ERROR_REPOSITORY, "unsupported extension name %s", entry->name);
	return -1;
}

static int check_extensions(git_config *config, int version)
{
	if (version < 1)
		return 0;

	return git_config_foreach_match(config, "^extensions\\.", check_valid_extension, NULL);
}

And I check the version: repositoryformatversion = 1, So all extension configs will failed.

[vermiculus]

Is there a to-do list or anything of the sort for this? Or is this as simple as updating git_config_level_t to insert some GIT_CONFIG_LEVEL_WORKTREE and updating users of that type?

I'm also assuming the new value will need to be ordered between _LOCAL and _APP, which could potentially introduce issues (but would maintain the likely expectation that 'values closer to zero' => 'more general').

[frankcbliu]

the same problem, is there any support plan for this?

[vermiculus]

@frankcbliu I've got a PR in progress mentioned above, though it's having some as-yet-unknown test failures on some platforms. Any help for this would be welcomed.

[ethomson]

Fixed via #6756