[PATCH v3 7/7] send-pack: pass negotiation config in push

["Derrick Stolee via GitGitGadget" <gitgitgadget@gmail.com>]

From: Derrick Stolee <stolee@gmail.com>

When push.negotiate is enabled, 'git push' spawns a child 'git fetch
--negotiate-only' process to find common commits.  Pass
--negotiation-include and --negotiation-restrict options from the
'remote.<name>.negotiationInclude' and
'remote.<name>.negotiationRestrict' config keys to this child process.

When negotiationRestrict is configured, it replaces the default
behavior of using all remote refs as negotiation tips. This allows
the user to control which local refs are used for push negotiation.

When negotiationInclude is configured, the specified ref patterns
are passed as --negotiation-include to ensure their tips are always
sent as 'have' lines during push negotiation.

This change also updates the use of --negotiation-tip into
--negotiation-restrict now that the new synonym exists.

Signed-off-by: Derrick Stolee <stolee@gmail.com>
---
 send-pack.c           | 39 +++++++++++++++++++++++++++++++--------
 send-pack.h           |  2 ++
 t/t5516-fetch-push.sh | 30 ++++++++++++++++++++++++++++++
 transport.c           |  2 ++
 4 files changed, 65 insertions(+), 8 deletions(-)

diff --git a/send-pack.c b/send-pack.c
index 67d6987b1c..d18e030ce8 100644
--- a/send-pack.c
+++ b/send-pack.c
@@ -433,28 +433,48 @@ static void reject_invalid_nonce(const char *nonce, int len)
 
 static void get_commons_through_negotiation(struct repository *r,
 					    const char *url,
+					    const struct string_list *negotiation_include,
+					    const struct string_list *negotiation_restrict,
 					    const struct ref *remote_refs,
 					    struct oid_array *commons)
 {
 	struct child_process child = CHILD_PROCESS_INIT;
 	const struct ref *ref;
 	int len = r->hash_algo->hexsz + 1; /* hash + NL */
-	int nr_negotiation_tip = 0;
+	int nr_negotiation = 0;
 
 	child.git_cmd = 1;
 	child.no_stdin = 1;
 	child.out = -1;
 	strvec_pushl(&child.args, "fetch", "--negotiate-only", NULL);
-	for (ref = remote_refs; ref; ref = ref->next) {
-		if (!is_null_oid(&ref->new_oid)) {
-			strvec_pushf(&child.args, "--negotiation-tip=%s",
-				     oid_to_hex(&ref->new_oid));
-			nr_negotiation_tip++;
+
+	if (negotiation_restrict && negotiation_restrict->nr) {
+		struct string_list_item *item;
+		for_each_string_list_item(item, negotiation_restrict)
+			strvec_pushf(&child.args, "--negotiation-restrict=%s",
+				     item->string);
+		nr_negotiation = negotiation_restrict->nr;
+	} else {
+		for (ref = remote_refs; ref; ref = ref->next) {
+			if (!is_null_oid(&ref->new_oid)) {
+				strvec_pushf(&child.args, "--negotiation-restrict=%s",
+					     oid_to_hex(&ref->new_oid));
+				nr_negotiation++;
+			}
 		}
 	}
+
+	if (negotiation_include && negotiation_include->nr) {
+		struct string_list_item *item;
+		for_each_string_list_item(item, negotiation_include)
+			strvec_pushf(&child.args, "--negotiation-include=%s",
+				     item->string);
+		nr_negotiation += negotiation_include->nr;
+	}
+
 	strvec_push(&child.args, url);
 
-	if (!nr_negotiation_tip) {
+	if (!nr_negotiation) {
 		child_process_clear(&child);
 		return;
 	}
@@ -528,7 +548,10 @@ int send_pack(struct repository *r,
 	repo_config_get_bool(r, "push.negotiate", &push_negotiate);
 	if (push_negotiate) {
 		trace2_region_enter("send_pack", "push_negotiate", r);
-		get_commons_through_negotiation(r, args->url, remote_refs, &commons);
+		get_commons_through_negotiation(r, args->url,
+					       args->negotiation_include,
+					       args->negotiation_restrict,
+					       remote_refs, &commons);
 		trace2_region_leave("send_pack", "push_negotiate", r);
 	}
 
diff --git a/send-pack.h b/send-pack.h
index c5ded2d200..13850c98bb 100644
--- a/send-pack.h
+++ b/send-pack.h
@@ -18,6 +18,8 @@ struct repository;
 
 struct send_pack_args {
 	const char *url;
+	const struct string_list *negotiation_include;
+	const struct string_list *negotiation_restrict;
 	unsigned verbose:1,
 		quiet:1,
 		porcelain:1,
diff --git a/t/t5516-fetch-push.sh b/t/t5516-fetch-push.sh
index ac8447f21e..177cbc6c75 100755
--- a/t/t5516-fetch-push.sh
+++ b/t/t5516-fetch-push.sh
@@ -254,6 +254,36 @@ test_expect_success 'push with negotiation does not attempt to fetch submodules'
 	! grep "Fetching submodule" err
 '
 
+test_expect_success 'push with negotiation and remote.<name>.negotiationInclude' '
+	test_when_finished rm -rf negotiation_include &&
+	mk_empty negotiation_include &&
+	git push negotiation_include $the_first_commit:refs/remotes/origin/first_commit &&
+	test_commit -C negotiation_include unrelated_commit &&
+	git -C negotiation_include config receive.hideRefs refs/remotes/origin/first_commit &&
+	test_when_finished "rm event" &&
+	GIT_TRACE2_EVENT="$(pwd)/event" \
+		git -c protocol.version=2 -c push.negotiate=1 \
+		-c remote.negotiation_include.negotiationInclude=refs/heads/main \
+		push negotiation_include refs/heads/main:refs/remotes/origin/main &&
+	test_grep \"key\":\"total_rounds\" event &&
+	grep_wrote 2 event # 1 commit, 1 tree
+'
+
+test_expect_success 'push with negotiation and remote.<name>.negotiationRestrict' '
+	test_when_finished rm -rf negotiation_restrict &&
+	mk_empty negotiation_restrict &&
+	git push negotiation_restrict $the_first_commit:refs/remotes/origin/first_commit &&
+	test_commit -C negotiation_restrict unrelated_commit &&
+	git -C negotiation_restrict config receive.hideRefs refs/remotes/origin/first_commit &&
+	test_when_finished "rm event" &&
+	GIT_TRACE2_EVENT="$(pwd)/event" \
+		git -c protocol.version=2 -c push.negotiate=1 \
+		-c remote.negotiation_restrict.negotiationRestrict=refs/heads/main \
+		push negotiation_restrict refs/heads/main:refs/remotes/origin/main &&
+	test_grep \"key\":\"total_rounds\" event &&
+	grep_wrote 2 event # 1 commit, 1 tree
+'
+
 test_expect_success 'push without wildcard' '
 	mk_empty testrepo &&
 
diff --git a/transport.c b/transport.c
index 8a2d8adffc..60b73feb34 100644
--- a/transport.c
+++ b/transport.c
@@ -921,6 +921,8 @@ static int git_transport_push(struct transport *transport, struct ref *remote_re
 	args.atomic = !!(flags & TRANSPORT_PUSH_ATOMIC);
 	args.push_options = transport->push_options;
 	args.url = transport->url;
+	args.negotiation_include = &transport->remote->negotiation_include;
+	args.negotiation_restrict = &transport->remote->negotiation_restrict;
 
 	if (flags & TRANSPORT_PUSH_CERT_ALWAYS)
 		args.push_cert = SEND_PACK_PUSH_CERT_ALWAYS;
-- 
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