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* [PATCH 0/2] Fix shallow clone with ref-in-want enabled
@ 2025-12-24  0:35 Matthew Dodd
  2025-12-24  0:35 ` [PATCH 1/2] upload-pack: send shallow-info before wanted-refs in protocol v2 Matthew Dodd
  2025-12-24  0:35 ` [PATCH 2/2] t5703: add test for shallow fetch with ref-in-want Matthew Dodd
  0 siblings, 2 replies; 4+ messages in thread
From: Matthew Dodd @ 2025-12-24  0:35 UTC (permalink / raw)
  To: git; +Cc: Brandon Williams, Junio C Hamano, Johannes Schindelin, Mats-Dodd

From: Mats-Dodd <mats.dodd12@gmail•com>

The ref-in-want feature (uploadpack.allowRefInWant) has been broken with
shallow clones since it was introduced in 516e2b76bdc (upload-pack:
implement ref-in-want, 2018-06-27). When enabled, shallow clones fail
with:

    fatal: expected 'packfile', received 'shallow-info'

The server sends protocol v2 sections in the wrong order, violating the
specification in Documentation/gitprotocol-v2.adoc and client expectations
in fetch-pack.c.

This series:
1. Fixes the section ordering in upload-pack.c (swap two lines)
2. Adds a regression test for shallow clone + ref-in-want

Mats-Dodd (2):
  upload-pack: send shallow-info before wanted-refs in protocol v2
  t5703: add test for shallow fetch with ref-in-want

 t/t5703-upload-pack-ref-in-want.sh | 9 +++++++++
 upload-pack.c                      | 2 +-
 2 files changed, 10 insertions(+), 1 deletion(-)


base-commit: 9a2fb147f2c61d0cab52c883e7e26f5b7948e3ed
-- 
2.47.0


^ permalink raw reply	[flat|nested] 4+ messages in thread

* [PATCH 1/2] upload-pack: send shallow-info before wanted-refs in protocol v2
  2025-12-24  0:35 [PATCH 0/2] Fix shallow clone with ref-in-want enabled Matthew Dodd
@ 2025-12-24  0:35 ` Matthew Dodd
  2026-01-05 13:00   ` Patrick Steinhardt
  2025-12-24  0:35 ` [PATCH 2/2] t5703: add test for shallow fetch with ref-in-want Matthew Dodd
  1 sibling, 1 reply; 4+ messages in thread
From: Matthew Dodd @ 2025-12-24  0:35 UTC (permalink / raw)
  To: git; +Cc: Brandon Williams, Junio C Hamano, Johannes Schindelin, Mats-Dodd

From: Mats-Dodd <mats.dodd12@gmail•com>

The protocol v2 specification (Documentation/gitprotocol-v2.adoc) defines
the ordering of optional sections in the fetch response as:

    [acknowledgments delim-pkt] [shallow-info delim-pkt]
    [wanted-refs delim-pkt] [packfile-uris delim-pkt]
    packfile flush-pkt

However, since the ref-in-want feature was introduced in 516e2b76bdc
(upload-pack: implement ref-in-want, 2018-06-27), the server sends
wanted-refs before shallow-info. This violates the specification and
breaks the client (fetch-pack.c), which expects shallow-info first.

When a client performs a shallow clone/fetch against a server with
uploadpack.allowRefInWant=true, the client receives sections in the
wrong order and fails with:

    fatal: expected 'packfile', received 'shallow-info'

Fix by swapping the order of send_shallow_info() and
send_wanted_ref_info() to match both the protocol specification and
client expectations.

Signed-off-by: Mats-Dodd <mats.dodd12@gmail•com>
---
 upload-pack.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/upload-pack.c b/upload-pack.c
index 1e87ae9559..029ca93e69 100644
--- a/upload-pack.c
+++ b/upload-pack.c
@@ -1830,8 +1830,8 @@ int upload_pack_v2(struct repository *r, struct packet_reader *request)
 				state = UPLOAD_DONE;
 			break;
 		case UPLOAD_SEND_PACK:
-			send_wanted_ref_info(&data);
 			send_shallow_info(&data);
+			send_wanted_ref_info(&data);
 
 			if (data.uri_protocols.nr) {
 				create_pack_file(&data, &data.uri_protocols);
-- 
2.47.0


^ permalink raw reply related	[flat|nested] 4+ messages in thread

* [PATCH 2/2] t5703: add test for shallow fetch with ref-in-want
  2025-12-24  0:35 [PATCH 0/2] Fix shallow clone with ref-in-want enabled Matthew Dodd
  2025-12-24  0:35 ` [PATCH 1/2] upload-pack: send shallow-info before wanted-refs in protocol v2 Matthew Dodd
@ 2025-12-24  0:35 ` Matthew Dodd
  1 sibling, 0 replies; 4+ messages in thread
From: Matthew Dodd @ 2025-12-24  0:35 UTC (permalink / raw)
  To: git; +Cc: Brandon Williams, Junio C Hamano, Johannes Schindelin, Mats-Dodd

From: Mats-Dodd <mats.dodd12@gmail•com>

Add a regression test for shallow clone operations when the server has
uploadpack.allowRefInWant enabled. Before the previous commit, this
operation would fail with:

    fatal: expected 'packfile', received 'shallow-info'

This was due to the server sending protocol v2 sections in the wrong
order. The test ensures this scenario continues to work.

Signed-off-by: Mats-Dodd <mats.dodd12@gmail•com>
---
 t/t5703-upload-pack-ref-in-want.sh | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/t/t5703-upload-pack-ref-in-want.sh b/t/t5703-upload-pack-ref-in-want.sh
index 249137b467..21f4049eb4 100755
--- a/t/t5703-upload-pack-ref-in-want.sh
+++ b/t/t5703-upload-pack-ref-in-want.sh
@@ -256,6 +256,15 @@ test_expect_success 'fetching multiple refs' '
 	grep "want-ref refs/heads/baz" log
 '
 
+test_expect_success 'fetching with ref-in-want and shallow' '
+	rm -rf local &&
+	git -c protocol.version=2 clone --depth=1 "file://$REPO" local &&
+
+	git -C "$REPO" rev-parse main >expected &&
+	git -C local rev-parse refs/remotes/origin/main >actual &&
+	test_cmp expected actual
+'
+
 test_expect_success 'fetching ref and exact OID' '
 	test_when_finished "rm -f log" &&
 
-- 
2.47.0


^ permalink raw reply related	[flat|nested] 4+ messages in thread

* Re: [PATCH 1/2] upload-pack: send shallow-info before wanted-refs in protocol v2
  2025-12-24  0:35 ` [PATCH 1/2] upload-pack: send shallow-info before wanted-refs in protocol v2 Matthew Dodd
@ 2026-01-05 13:00   ` Patrick Steinhardt
  0 siblings, 0 replies; 4+ messages in thread
From: Patrick Steinhardt @ 2026-01-05 13:00 UTC (permalink / raw)
  To: Matthew Dodd; +Cc: git, Brandon Williams, Junio C Hamano, Johannes Schindelin

On Wed, Dec 24, 2025 at 01:35:03AM +0100, Matthew Dodd wrote:
> From: Mats-Dodd <mats.dodd12@gmail•com>
> 
> The protocol v2 specification (Documentation/gitprotocol-v2.adoc) defines
> the ordering of optional sections in the fetch response as:
> 
>     [acknowledgments delim-pkt] [shallow-info delim-pkt]
>     [wanted-refs delim-pkt] [packfile-uris delim-pkt]
>     packfile flush-pkt
> 
> However, since the ref-in-want feature was introduced in 516e2b76bdc
> (upload-pack: implement ref-in-want, 2018-06-27), the server sends
> wanted-refs before shallow-info. This violates the specification and
> breaks the client (fetch-pack.c), which expects shallow-info first.
> 
> When a client performs a shallow clone/fetch against a server with
> uploadpack.allowRefInWant=true, the client receives sections in the
> wrong order and fails with:
> 
>     fatal: expected 'packfile', received 'shallow-info'
> 
> Fix by swapping the order of send_shallow_info() and

Nit: is there a word missing here? E.g. "Fix this by..."

> diff --git a/upload-pack.c b/upload-pack.c
> index 1e87ae9559..029ca93e69 100644
> --- a/upload-pack.c
> +++ b/upload-pack.c
> @@ -1830,8 +1830,8 @@ int upload_pack_v2(struct repository *r, struct packet_reader *request)
>  				state = UPLOAD_DONE;
>  			break;
>  		case UPLOAD_SEND_PACK:
> -			send_wanted_ref_info(&data);
>  			send_shallow_info(&data);
> +			send_wanted_ref_info(&data);

Indeed. The accompanying code in "fetch-pack.c" expects information the
other way round:

	if (process_section_header(&reader, "shallow-info", 1))
		receive_shallow_info(args, &reader, shallows, si);

	if (process_section_header(&reader, "wanted-refs", 1))
		receive_wanted_refs(&reader, sought, nr_sought);

The bug seems to exist since the inception of this feature. 516e2b76bd
(upload-pack: implement ref-in-want, 2018-06-27) implements the server
side in the current-broken way, and 733020517a (fetch-pack: implement
ref-in-want, 2018-06-27) implements the client side in the correct way.
So this combination has always been broken, and the fix looks obviously
correct to me indeed.

One nit though: I don't really think it's necessary to split up this
series into two patches. The new test can simply be added to this commit
here.

Thanks!

Patrick

^ permalink raw reply	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2026-01-05 13:00 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2025-12-24  0:35 [PATCH 0/2] Fix shallow clone with ref-in-want enabled Matthew Dodd
2025-12-24  0:35 ` [PATCH 1/2] upload-pack: send shallow-info before wanted-refs in protocol v2 Matthew Dodd
2026-01-05 13:00   ` Patrick Steinhardt
2025-12-24  0:35 ` [PATCH 2/2] t5703: add test for shallow fetch with ref-in-want Matthew Dodd

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