[PATCH 02/14] upload-pack.c: Refactor capability advertising

[Stefan Beller <sbeller@google.com>]

Instead of having the capabilities in a local string, keep them
in a struct outside the function. This will allow us in a later patch
to easily reuse the capabilities in version 2 of the protocol.

Signed-off-by: Stefan Beller <sbeller@google.com>
---
 upload-pack.c | 59 ++++++++++++++++++++++++++++++++++++++++-------------------
 1 file changed, 40 insertions(+), 19 deletions(-)

diff --git a/upload-pack.c b/upload-pack.c
index aaaf883..85381d5 100644
--- a/upload-pack.c
+++ b/upload-pack.c
@@ -719,37 +719,58 @@ static void format_symref_info(struct strbuf *buf, struct string_list *symref)
 		strbuf_addf(buf, " symref=%s:%s", item->string, (char *)item->util);
 }
 
+static int advertise_capabilities = 1;
+const char *all_capabilities[] = {
+	"multi_ack",
+	"thin-pack",
+	"side-band",
+	"side-band-64k",
+	"ofs-delta",
+	"shallow",
+	"no-progress",
+	"include-tag",
+	"multi_ack_detailed",
+	"allow-tip-sha1-in-want",
+	"allow-reachable-sha1-in-want",
+	"no-done",
+};
+
 static int send_ref(const char *refname, const struct object_id *oid,
 		    int flag, void *cb_data)
 {
-	static const char *capabilities = "multi_ack thin-pack side-band"
-		" side-band-64k ofs-delta shallow no-progress"
-		" include-tag multi_ack_detailed";
 	const char *refname_nons = strip_namespace(refname);
 	struct object_id peeled;
 
 	if (mark_our_ref(refname_nons, refname, oid))
 		return 0;
 
-	if (capabilities) {
-		struct strbuf symref_info = STRBUF_INIT;
-
-		format_symref_info(&symref_info, cb_data);
-		packet_write(1, "%s %s%c%s%s%s%s%s agent=%s\n",
-			     oid_to_hex(oid), refname_nons,
-			     0, capabilities,
-			     (allow_unadvertised_object_request & ALLOW_TIP_SHA1) ?
-				     " allow-tip-sha1-in-want" : "",
-			     (allow_unadvertised_object_request & ALLOW_REACHABLE_SHA1) ?
-				     " allow-reachable-sha1-in-want" : "",
-			     stateless_rpc ? " no-done" : "",
-			     symref_info.buf,
-			     git_user_agent_sanitized());
-		strbuf_release(&symref_info);
+	if (advertise_capabilities) {
+		int i;
+		struct strbuf capabilities = STRBUF_INIT;
+
+		for (i = 0; i < ARRAY_SIZE(all_capabilities); i++) {
+			const char *cap = all_capabilities[i];
+			if (!strcmp(cap, "allow-tip-sha1-in-want")
+			    && !(allow_unadvertised_object_request & ALLOW_TIP_SHA1))
+				continue;
+			if (!strcmp(cap, "allow-reachable-sha1-in-want")
+			    && !(allow_unadvertised_object_request & ALLOW_REACHABLE_SHA1))
+				continue;
+			if (!strcmp(cap, "no-done") && !stateless_rpc)
+				continue;
+			strbuf_addf(&capabilities, " %s", cap);
+		}
+
+		format_symref_info(&capabilities, cb_data);
+		strbuf_addf(&capabilities, " agent=%s", git_user_agent_sanitized());
+
+		packet_write(1, "%s %s%c%s\n", oid_to_hex(oid), refname_nons,
+			     0, capabilities.buf);
+		strbuf_release(&capabilities);
+		advertise_capabilities = 0;
 	} else {
 		packet_write(1, "%s %s\n", oid_to_hex(oid), refname_nons);
 	}
-	capabilities = NULL;
 	if (!peel_ref(refname, peeled.hash))
 		packet_write(1, "%s %s^{}\n", oid_to_hex(&peeled), refname_nons);
 	return 0;
-- 
2.8.0.32.g71f8beb.dirty