send-pack: fix push.negotiate with remote helper

Commit 477673d6f3 ("send-pack: support push negotiation", 2021-05-05)
introduced the push.negotiate config variable and included a test. The
test only covered pushing without a remote helper, so the fact that
pushing with a remote helper doesn't work went unnoticed.

This is ultimately caused by the "url" field not being set in the args
struct. This field being unset probably went unnoticed because besides
push negotiation, this field is only used to generate a "pushee" line in
a push cert (and if not given, no such line is generated). Therefore,
set this field.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin/send-pack.c

@@ -230,6 +230,7 @@ int cmd_send_pack(int argc, const char **argv, const char *prefix)
 	args.atomic = atomic;
 	args.stateless_rpc = stateless_rpc;
 	args.push_options = push_options.nr ? &push_options : NULL;
+	args.url = dest;
 
 	if (from_stdin) {
 		if (args.stateless_rpc) {

t/t5549-fetch-push-http.sh

@@ -0,0 +1,71 @@
+#!/bin/sh
+
+test_description='fetch/push functionality using the HTTP protocol'
+
+GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=main
+export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME
+
+. ./test-lib.sh
+. "$TEST_DIRECTORY"/lib-httpd.sh
+start_httpd
+
+SERVER="$HTTPD_DOCUMENT_ROOT_PATH/server"
+URI="$HTTPD_URL/smart/server"
+
+grep_wrote () {
+	object_count=$1
+	file_name=$2
+	grep 'write_pack_file/wrote.*"value":"'$1'"' $2
+}
+
+setup_client_and_server () {
+	git init client &&
+	test_when_finished 'rm -rf client' &&
+	test_commit -C client first_commit &&
+	test_commit -C client second_commit &&
+
+	git init "$SERVER" &&
+	test_when_finished 'rm -rf "$SERVER"' &&
+	test_config -C "$SERVER" http.receivepack true &&
+	git -C client push "$URI" first_commit:refs/remotes/origin/first_commit &&
+	git -C "$SERVER" config receive.hideRefs refs/remotes/origin/first_commit
+}
+
+test_expect_success 'push without negotiation (for comparing object counts with the next test)' '
+	setup_client_and_server &&
+
+	GIT_TRACE2_EVENT="$(pwd)/event" git -C client -c protocol.version=2 \
+		push "$URI" refs/heads/main:refs/remotes/origin/main &&
+	test_when_finished "rm -f event" &&
+	grep_wrote 6 event # 2 commits, 2 trees, 2 blobs
+'
+
+test_expect_success 'push with negotiation' '
+	setup_client_and_server &&
+
+	GIT_TRACE2_EVENT="$(pwd)/event" git -C client -c protocol.version=2 -c push.negotiate=1 \
+		push "$URI" refs/heads/main:refs/remotes/origin/main &&
+	test_when_finished "rm -f event" &&
+	grep_wrote 3 event # 1 commit, 1 tree, 1 blob
+'
+
+test_expect_success 'push with negotiation proceeds anyway even if negotiation fails' '
+	setup_client_and_server &&
+
+	# Use protocol v0 to make negotiation fail (because protocol v0 does
+	# not support the "wait-for-done" capability, which is required for
+	# push negotiation)
+	GIT_TEST_PROTOCOL_VERSION=0 GIT_TRACE2_EVENT="$(pwd)/event" git -C client -c push.negotiate=1 \
+		push "$URI" refs/heads/main:refs/remotes/origin/main 2>err &&
+	test_when_finished "rm -f event" &&
+	grep_wrote 6 event && # 2 commits, 2 trees, 2 blobs
+
+	cat >warning-expect <<-EOF &&
+	warning: --negotiate-only requires protocol v2
+	warning: push negotiation failed; proceeding anyway with push
+EOF
+	grep warning: err >warning-actual &&
+	test_cmp warning-expect warning-actual
+'
+
+test_done