Re: [PATCH 4/4] promisor-remote: teach lazy-fetch in any repo

>
> This is one step towards supporting partial clone submodules.
>
> Even after this patch, we will still lack partial clone submodules
> support, primarily because a lot of Git code that accesses submodule
> objects does so by adding their object stores as alternates, meaning
> that any lazy fetches that would occur in the submodule would be done
> based on the config of the superproject, not of the submodule. This also
> prevents testing of the functionality in this patch by user-facing
> commands. So for now, test this mechanism using a test helper.
>

> diff --git a/t/helper/test-partial-clone.c b/t/helper/test-partial-clone.c
> new file mode 100644
> index 0000000000..e7bc7eb21f
> --- /dev/null
> +++ b/t/helper/test-partial-clone.c
> @@ -0,0 +1,34 @@
> +#include "cache.h"
> +#include "test-tool.h"
> +#include "repository.h"
> +#include "object-store.h"
> +
> +static void object_info(const char *gitdir, const char *oid_hex)
> +{
> +       struct repository r;
> +       struct object_id oid;
> +       unsigned long size;
> +       struct object_info oi = {.sizep = &size};
> +       const char *p;
> +
> +       if (repo_init(&r, gitdir, NULL))
> +               die("could not init repo");
> +       if (parse_oid_hex(oid_hex, &oid, &p))
> +               die("could not parse oid");
> +       if (oid_object_info_extended(&r, &oid, &oi, 0))
> +               die("could not obtain object info");
> +       printf("%d\n", (int) size);
> +}
> +
> +int cmd__partial_clone(int argc, const char **argv)
> +{
> +       if (argc < 4)
> +               die("too few arguments");
> +
> +       if (!strcmp(argv[1], "object-info"))
> +               object_info(argv[2], argv[3]);
> +       else
> +               die("invalid argument '%s'", argv[1]);
> +
> +       return 0;
> +}
> diff --git a/t/helper/test-tool.c b/t/helper/test-tool.c
> index c5bd0c6d4c..b21e8f1519 100644
> --- a/t/helper/test-tool.c
> +++ b/t/helper/test-tool.c
> @@ -46,6 +46,7 @@ static struct test_cmd cmds[] = {
>         { "online-cpus", cmd__online_cpus },
>         { "parse-options", cmd__parse_options },
>         { "parse-pathspec-file", cmd__parse_pathspec_file },
> +       { "partial-clone", cmd__partial_clone },
>         { "path-utils", cmd__path_utils },
>         { "pcre2-config", cmd__pcre2_config },
>         { "pkt-line", cmd__pkt_line },
> diff --git a/t/helper/test-tool.h b/t/helper/test-tool.h
> index e8069a3b22..f845ced4b3 100644
> --- a/t/helper/test-tool.h
> +++ b/t/helper/test-tool.h
> @@ -35,6 +35,7 @@ int cmd__oidmap(int argc, const char **argv);
>  int cmd__online_cpus(int argc, const char **argv);
>  int cmd__parse_options(int argc, const char **argv);
>  int cmd__parse_pathspec_file(int argc, const char** argv);
> +int cmd__partial_clone(int argc, const char **argv);
>  int cmd__path_utils(int argc, const char **argv);
>  int cmd__pcre2_config(int argc, const char **argv);
>  int cmd__pkt_line(int argc, const char **argv);
> diff --git a/t/t0410-partial-clone.sh b/t/t0410-partial-clone.sh
> index 584a039b85..e804d267e6 100755
> --- a/t/t0410-partial-clone.sh
> +++ b/t/t0410-partial-clone.sh
> @@ -604,6 +604,30 @@ test_expect_success 'do not fetch when checking existence of tree we construct o
>         git -C repo cherry-pick side1
>  '
>
> +test_expect_success 'lazy-fetch when accessing object not in the_repository' '
> +       rm -rf full partial.git &&
> +       test_create_repo full &&
> +       printf 12345 >full/file.txt &&
> +       git -C full add file.txt &&
> +       git -C full commit -m "first commit" &&
> +
> +       test_config -C full uploadpack.allowfilter 1 &&
> +       test_config -C full uploadpack.allowanysha1inwant 1 &&
> +       git clone --filter=blob:none --bare "file://$(pwd)/full" partial.git &&
> +       FILE_HASH=$(git hash-object --stdin <full/file.txt) &&
> +
> +       # Sanity check that the file is missing
> +       git -C partial.git rev-list --objects --missing=print HEAD >out &&
> +       grep "[?]$FILE_HASH" out &&
> +
> +       OUT=$(test-tool partial-clone object-info partial.git "$FILE_HASH") &&
> +       test "$OUT" -eq 5 &&
> +
> +       # Sanity check that the file is now present
> +       git -C partial.git rev-list --objects --missing=print HEAD >out &&
> +       ! grep "[?]$FILE_HASH" out
> +'
> +