[PATCH v5 3/5] hiderefs: hornor hide flags in wire protocol V2

["Sun Chao via GitGitGadget" <gitgitgadget@xxxxxxxxx>]

From: Sun Chao <sunchao9@xxxxxxxxxx>

Previously hide refs can not protect private data of hide refs in wire
protocol V2, for example a `ALL_FLAGS` will be used to clear all the
objects before handling the fetch requests.

Hornor the hide flags by removing `HIDDEN_REFS` flag from `ALL_FLAGS`
and make sure all the refs will check its hidden flags before sending pack
to client, especially during stateless rpc. And if there are refs with
`HIDDEN_REF_FORCE` flag, use `check_non_tip` to protect the private date
of force hidden refs.

Signed-off-by: Sun Chao <sunchao9@xxxxxxxxxx>
---
 ls-refs.c     |  2 +-
 refs.c        | 20 ++++++++++++++++++++
 refs.h        |  4 ++++
 upload-pack.c | 11 +++++++++--
 4 files changed, 34 insertions(+), 3 deletions(-)

diff --git a/ls-refs.c b/ls-refs.c
index 98e69373c84..b5cb1316d38 100644
--- a/ls-refs.c
+++ b/ls-refs.c
@@ -84,7 +84,7 @@ static int send_ref(const char *refname, const struct object_id *oid,
 
 	strbuf_reset(&data->buf);
 
-	if (ref_is_hidden(refname_nons, refname))
+	if (mark_our_ref(refname_nons, refname, oid))
 		return 0;
 
 	if (!ref_match(&data->prefixes, refname_nons))
diff --git a/refs.c b/refs.c
index 3fbdf967bc6..1424de0048e 100644
--- a/refs.c
+++ b/refs.c
@@ -1662,6 +1662,25 @@ int ref_is_hidden(const char *refname, const char *refname_full)
  */
 #define HIDDEN_REF_FORCE	(1u << 20)
 
+/* Use this variable to record existing object hidden flags */
+static unsigned int objects_hidden_flags;
+
+/* Return non-zero if need to batch check hidden refs, otherwise 0 */
+int need_check_hidden_refs(void)
+{
+	if (!objects_hidden_flags)
+		return 1;
+	return 0;
+}
+
+/* Return non-zero if some ref is force hidden, otherwise 0 */
+int has_force_hidden_refs(void)
+{
+	if (objects_hidden_flags & HIDDEN_REF_FORCE)
+		return 1;
+	return 0;
+}
+
 static unsigned int ref_hidden_flag(const char *refname, const char *refname_full)
 {
 	if (ref_hidden_check(refname, refname_full, 1))
@@ -1684,6 +1703,7 @@ int mark_our_ref(const char *refname, const char *refname_full,
 	o = lookup_unknown_object(the_repository, oid);
 	flag = ref_hidden_flag(refname, refname_full);
 	o->flags |= flag;
+	objects_hidden_flags |= flag;
 
 	if (flag & OUR_REF)
 		return 0;
diff --git a/refs.h b/refs.h
index 2feabfe35c4..8deb36a95cc 100644
--- a/refs.h
+++ b/refs.h
@@ -822,6 +822,10 @@ int ref_is_hidden(const char *, const char *);
 /* return non-zero if the ref is hidden, otherwise 0 */
 int mark_our_ref(const char *refname, const char *refname_full,
 		 const struct object_id *oid);
+/* return non-zero if need to batch check hidden refs, otherwise 0 */
+int need_check_hidden_refs(void);
+/* return non-zero if some ref is force hidden, otherwise 0 */
+int has_force_hidden_refs(void);
 
 enum ref_type {
 	REF_TYPE_PER_WORKTREE,	  /* refs inside refs/ but not shared       */
diff --git a/upload-pack.c b/upload-pack.c
index a8ca5d1c26e..a9a24399d8e 100644
--- a/upload-pack.c
+++ b/upload-pack.c
@@ -39,8 +39,8 @@
 #define CLIENT_SHALLOW	(1u << 18)
 #define HIDDEN_REF	(1u << 19)
 
-#define ALL_FLAGS (THEY_HAVE | OUR_REF | WANTED | COMMON_KNOWN | SHALLOW | \
-		NOT_SHALLOW | CLIENT_SHALLOW | HIDDEN_REF)
+#define ALL_FLAGS (THEY_HAVE |WANTED | COMMON_KNOWN | SHALLOW | \
+		NOT_SHALLOW | CLIENT_SHALLOW)
 
 /* Enum for allowed unadvertised object request (UOR) */
 enum allow_uor {
@@ -1726,6 +1726,13 @@ int upload_pack_v2(struct repository *r, struct packet_reader *request)
 				state = FETCH_DONE;
 			break;
 		case FETCH_SEND_PACK:
+			if (need_check_hidden_refs()) {
+				head_ref_namespaced(check_ref, NULL);
+				for_each_namespaced_ref(check_ref, NULL);
+			}
+			if (has_force_hidden_refs())
+				check_non_tip(&data);
+
 			send_wanted_ref_info(&data);
 			send_shallow_info(&data);
 
-- 
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