upload-pack: document and rename --advertise-refs

The --advertise-refs documentation in git-upload-pack added in
9812f2136b3 (upload-pack.c: use parse-options API, 2016-05-31) hasn't
been entirely true ever since v2 support was implemented in
e52449b6722 (connect: request remote refs using v2, 2018-03-15). Under
v2 we don't advertise the refs at all, but rather dump the
capabilities header.

This option has always been an obscure internal implementation detail,
it wasn't even documented for git-receive-pack. Since it has exactly
one user let's rename it to --http-backend-info-refs, which is more
accurate and points the reader in the right direction. Let's also
cross-link this from the protocol v1 and v2 documentation.

I'm retaining a hidden --advertise-refs alias in case there's any
external users of this, and making both options hidden to the bash
completion (as with most other internal-only options).

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

8 files changed, 39 insertions, 8 deletions

diff --git a/Documentation/git-receive-pack.txt b/Documentation/git-receive-pack.txt
index 25702ed730..014a78409b 100644
--- a/Documentation/git-receive-pack.txt
+++ b/Documentation/git-receive-pack.txt
@@ -41,6 +41,11 @@ OPTIONS
 <directory>::
 	The repository to sync into.
 
+--http-backend-info-refs::
+	Used by linkgit:git-http-backend[1] to serve up
+	`$GIT_URL/info/refs?service=git-receive-pack` requests. See
+	`--http-backend-info-refs` in linkgit:git-upload-pack[1].
+
 PRE-RECEIVE HOOK
 ----------------
 Before any ref is updated, if $GIT_DIR/hooks/pre-receive file exists
diff --git a/Documentation/git-upload-pack.txt b/Documentation/git-upload-pack.txt
index 9822c1eb1a..739416ec83 100644
--- a/Documentation/git-upload-pack.txt
+++ b/Documentation/git-upload-pack.txt
@@ -36,10 +36,14 @@ OPTIONS
 	This fits with the HTTP POST request processing model where
 	a program may read the request, write a response, and must exit.
 
---advertise-refs::
-	Only the initial ref advertisement is output, and the program exits
-	immediately. This fits with the HTTP GET request model, where
-	no request content is received but a response must be produced.
+--http-backend-info-refs::
+	Used by linkgit:git-http-backend[1] to serve up
+	`$GIT_URL/info/refs?service=git-upload-pack` requests. See
+	"Smart Clients" in link:technical/http-protocol.html[the HTTP
+	transfer protocols] documentation and "HTTP Transport" in
+	link:technical/protocol-v2.html[the Git Wire Protocol, Version
+	2] documentation. Also understood by
+	linkgit:git-receive-pack[1].
 
 <directory>::
 	The repository to sync from.
diff --git a/Documentation/technical/http-protocol.txt b/Documentation/technical/http-protocol.txt
index 96d89ea9b2..cc5126cfed 100644
--- a/Documentation/technical/http-protocol.txt
+++ b/Documentation/technical/http-protocol.txt
@@ -225,6 +225,9 @@ The client may send Extra Parameters (see
 Documentation/technical/pack-protocol.txt) as a colon-separated string
 in the Git-Protocol HTTP header.
 
+Uses the `--http-backend-info-refs` option to
+linkgit:git-upload-pack[1].
+
 Dumb Server Response
 ^^^^^^^^^^^^^^^^^^^^
 Dumb servers MUST respond with the dumb server reply format.
diff --git a/Documentation/technical/protocol-v2.txt b/Documentation/technical/protocol-v2.txt
index 1040d85319..213538f1d0 100644
--- a/Documentation/technical/protocol-v2.txt
+++ b/Documentation/technical/protocol-v2.txt
@@ -81,6 +81,9 @@ A v2 server would reply:
 Subsequent requests are then made directly to the service
 `$GIT_URL/git-upload-pack`. (This works the same for git-receive-pack).
 
+Uses the `--http-backend-info-refs` option to
+linkgit:git-upload-pack[1].
+
 Capability Advertisement
 ------------------------
 
diff --git a/builtin/receive-pack.c b/builtin/receive-pack.c
index 2d1f97e1ca..7ffb45d706 100644
--- a/builtin/receive-pack.c
+++ b/builtin/receive-pack.c
@@ -2477,7 +2477,8 @@ int cmd_receive_pack(int argc, const char **argv, const char *prefix)
 	struct option options[] = {
 		OPT__QUIET(&quiet, N_("quiet")),
 		OPT_HIDDEN_BOOL(0, "stateless-rpc", &stateless_rpc, NULL),
-		OPT_HIDDEN_BOOL(0, "advertise-refs", &advertise_refs, NULL),
+		OPT_HIDDEN_BOOL(0, "http-backend-info-refs", &advertise_refs, NULL),
+		OPT_ALIAS(0, "advertise-refs", "http-backend-info-refs"),
 		OPT_HIDDEN_BOOL(0, "reject-thin-pack-for-testing", &reject_thin, NULL),
 		OPT_END()
 	};
diff --git a/builtin/upload-pack.c b/builtin/upload-pack.c
index 8506030a64..125af53885 100644
--- a/builtin/upload-pack.c
+++ b/builtin/upload-pack.c
@@ -22,8 +22,9 @@ int cmd_upload_pack(int argc, const char **argv, const char *prefix)
 	struct option options[] = {
 		OPT_BOOL(0, "stateless-rpc", &stateless_rpc,
 			 N_("quit after a single request/response exchange")),
-		OPT_BOOL(0, "advertise-refs", &advertise_refs,
-			 N_("exit immediately after initial ref advertisement")),
+		OPT_HIDDEN_BOOL(0, "http-backend-info-refs", &advertise_refs,
+				N_("serve up the info/refs for git-http-backend")),
+		OPT_ALIAS(0, "advertise-refs", "http-backend-info-refs"),
 		OPT_BOOL(0, "strict", &strict,
 			 N_("do not try <directory>/.git/ if <directory> is no Git directory")),
 		OPT_INTEGER(0, "timeout", &timeout,
diff --git a/http-backend.c b/http-backend.c
index d37463cec8..838374edb9 100644
--- a/http-backend.c
+++ b/http-backend.c
@@ -534,7 +534,7 @@ static void get_info_refs(struct strbuf *hdr, char *arg)
 
 	if (service_name) {
 		const char *argv[] = {NULL /* service name */,
-			"--advertise-refs",
+			"--http-backend-info-refs",
 			".", NULL};
 		struct rpc_service *svc = select_service(hdr, service_name);
 
diff --git a/t/t5555-http-smart-common.sh b/t/t5555-http-smart-common.sh
index b813099ed2..49faf5e283 100755
--- a/t/t5555-http-smart-common.sh
+++ b/t/t5555-http-smart-common.sh
@@ -8,6 +8,20 @@ test_expect_success 'setup' '
 	test_commit --no-tag initial
 '
 
+test_expect_success 'git upload-pack --http-backend-info-refs and --advertise-refs are aliased' '
+	git upload-pack --http-backend-info-refs . >expected 2>err.expected &&
+	git upload-pack --advertise-refs . >actual 2>err.actual &&
+	test_cmp err.expected err.actual &&
+	test_cmp expected actual
+'
+
+test_expect_success 'git receive-pack --http-backend-info-refs and --advertise-refs are aliased' '
+	git receive-pack --http-backend-info-refs . >expected 2>err.expected &&
+	git receive-pack --advertise-refs . >actual 2>err.actual &&
+	test_cmp err.expected err.actual &&
+	test_cmp expected actual
+'
+
 test_expect_success 'git upload-pack --advertise-refs' '
 	cat >expect <<-EOF &&
 	$(git rev-parse HEAD) HEAD