From: Glen Choo <chooglen@xxxxxxxxxx> In a repo with partially cloned submodules, "git restore --recurse-submodules" from the superproject can fail with "fatal: fetch doesn't support --super-prefix". This error is encountered when the super prefix is set (either by passing "--super-prefix" or by setting the GIT_INTERNAL_SUPER_PREFIX env var) on a command that isn't marked SUPPORT_SUPER_PREFIX. In this case, "git restore --recurse-submodules" invokes "git read-tree --super-prefix=<path to submodule>", which in turn, invokes a "git fetch" to fetch promisor objects. The usefulness of this "--super-prefix" check is up for debate, and there is WIP to get rid of the option altogether [1], but we can't just leave "git restore" broken in the meantime, so let's do the barest minimum to fix this without causing too much trouble for that effort. Mark cmd_fetch as SUPPORT_SUPER_PREFIX, and add a test that shows that this fixes the bug described above. There is precedent for using SUPPORT_SUPER_PREFIX solely as a workaround for the super prefix check (c.f. [2]), which is all the more reason to get rid of this check. [1] https://lore.kernel.org/git/Y27D8QUl3I2d4xNe@nand.local/ [2] 53fcfbc84f (fsmonitor--daemon: allow --super-prefix argument, 2022-05-26) Suggested-by: Ævar Arnfjörð Bjarmason <avarab@xxxxxxxxx> Signed-off-by: Glen Choo <chooglen@xxxxxxxxxx> --- fetch: support "--super-prefix" Since "git read-tree" is seriously broken at the moment, let's not keep it hostage to the work on [1]. This is Ævar's suggested change from [2] combined with my partial clone test case from [3]. I think we can take this regardless of where we are with the RFCs; it's simple and obvious enough that it adds virtually no churn to the RFCs. [1] https://lore.kernel.org/git/Y27D8QUl3I2d4xNe@nand.local/ [2] https://lore.kernel.org/git/221109.86y1skq08e.gmgdl@xxxxxxxxxxxxxxxxxxx [3] https://lore.kernel.org/git/20221109004708.97668-4-chooglen@xxxxxxxxxx Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-git-1378%2Fchooglen%2Ffetch%2Fsupport-super-prefix-v1 Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-git-1378/chooglen/fetch/support-super-prefix-v1 Pull-Request: https://github.com/git/git/pull/1378 builtin/fetch.c | 6 ++++++ git.c | 2 +- t/t5616-partial-clone.sh | 43 ++++++++++++++++++++++++++++++++++++++++ 3 files changed, 50 insertions(+), 1 deletion(-) diff --git a/builtin/fetch.c b/builtin/fetch.c index 7378cafeec9..9fd64e2f409 100644 --- a/builtin/fetch.c +++ b/builtin/fetch.c @@ -2114,6 +2114,12 @@ int cmd_fetch(int argc, const char **argv, const char *prefix) int result = 0; int prune_tags_ok = 1; + /* + * NEEDSWORK: we don't actually use "--super-prefix". Unset it + * so that we don't accidentally use it or pass it down. + */ + unsetenv(GIT_SUPER_PREFIX_ENVIRONMENT); + packet_trace_identity("fetch"); /* Record the command line for the reflog */ diff --git a/git.c b/git.c index 6662548986f..b971752f6f0 100644 --- a/git.c +++ b/git.c @@ -531,7 +531,7 @@ static struct cmd_struct commands[] = { { "env--helper", cmd_env__helper }, { "fast-export", cmd_fast_export, RUN_SETUP }, { "fast-import", cmd_fast_import, RUN_SETUP | NO_PARSEOPT }, - { "fetch", cmd_fetch, RUN_SETUP }, + { "fetch", cmd_fetch, RUN_SETUP | SUPPORT_SUPER_PREFIX }, { "fetch-pack", cmd_fetch_pack, RUN_SETUP | NO_PARSEOPT }, { "fmt-merge-msg", cmd_fmt_merge_msg, RUN_SETUP }, { "for-each-ref", cmd_for_each_ref, RUN_SETUP }, diff --git a/t/t5616-partial-clone.sh b/t/t5616-partial-clone.sh index 037941b95d2..9bec57a0476 100755 --- a/t/t5616-partial-clone.sh +++ b/t/t5616-partial-clone.sh @@ -644,6 +644,49 @@ test_expect_success 'repack does not loosen promisor objects' ' grep "loosen_unused_packed_objects/loosened:0" trace ' +test_expect_success 'setup src repo with submodules' ' + test_config_global protocol.file.allow always && + + git init src-sub && + git -C src-sub config uploadpack.allowfilter 1 && + git -C src-sub config uploadpack.allowanysha1inwant 1 && + + # This blob must be missing in the subsequent commit. + echo foo >src-sub/file && + git -C src-sub add file && + git -C src-sub commit -m "submodule one" && + SUB_ONE=$(git -C src-sub rev-parse HEAD) && + + echo bar >src-sub/file && + git -C src-sub add file && + git -C src-sub commit -m "submodule two" && + SUB_TWO=$(git -C src-sub rev-parse HEAD) && + + git init src-super && + git -C src-super config uploadpack.allowfilter 1 && + git -C src-super config uploadpack.allowanysha1inwant 1 && + git -C src-super submodule add ../src-sub src-sub && + + git -C src-super/src-sub checkout $SUB_ONE && + git -C src-super add src-sub && + git -C src-super commit -m "superproject one" && + + git -C src-super/src-sub checkout $SUB_TWO && + git -C src-super add src-sub && + git -C src-super commit -m "superproject two" +' + +test_expect_success 'lazy-fetch in submodule succeeds' ' + test_when_finished "rm -rf src-super src-sub client" && + + test_config_global protocol.file.allow always && + git clone --filter=blob:none --also-filter-submodules \ + --recurse-submodules "file://$(pwd)/src-super" client && + + # Trigger lazy-fetch from the superproject + git -C client restore --recurse-submodules --source=HEAD^ :/ +' + . "$TEST_DIRECTORY"/lib-httpd.sh start_httpd base-commit: 319605f8f00e402f3ea758a02c63534ff800a711 -- gitgitgadget
