From: Patrick Steinhardt <ps@pks.im>
Date: Wed, 7 Jan 2026 13:08:02 +0000 (+0100)
Subject: packfile: extend `is_delta` field to allow for "unknown" state
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=56be11f501151c4955fc4fd09a8c7a06c73b3f46;p=thirdparty%2Fgit.git

packfile: extend `is_delta` field to allow for "unknown" state

The `struct object_info::u::packed::is_delta` field determines whether
or not a specific object is stored as a delta. It only stores whether or
not the object is stored as delta, so it is treated as a boolean value.

This boolean is insufficient though: when reading a packed object via
`packfile_store_read_object_info()` we know to skip parsing the actual
object when the user didn't request any object-specific data. In that
case we won't read the object itself, but will only look up its position
in the packfile. Consequently, we do not know whether it is a delta or
not.

This isn't really an issue right now, as the check for an empty request
is broken. But a subsequent commit will fix it, and once we do we will
have the need to also represent an "unknown" delta state.

Prepare for this change by introducing a new enum that encodes the
object type. We don't use the "unknown" state just yet, but will start
to do so in a subsequent commit.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---

diff --git a/odb.h b/odb.h
index 73b0b87ad5..afae5e5c01 100644
--- a/odb.h
+++ b/odb.h
@@ -343,7 +343,12 @@ struct object_info {
 		struct {
 			struct packed_git *pack;
 			off_t offset;
-			unsigned int is_delta;
+			enum packed_object_type {
+				PACKED_OBJECT_TYPE_UNKNOWN,
+				PACKED_OBJECT_TYPE_FULL,
+				PACKED_OBJECT_TYPE_OFS_DELTA,
+				PACKED_OBJECT_TYPE_REF_DELTA,
+			} type;
 		} packed;
 	} u;
 };
diff --git a/packfile.c b/packfile.c
index b0c6665c87..cc797b2b6a 100644
--- a/packfile.c
+++ b/packfile.c
@@ -2159,8 +2159,18 @@ int packfile_store_read_object_info(struct packfile_store *store,
 	if (oi->whence == OI_PACKED) {
 		oi->u.packed.offset = e.offset;
 		oi->u.packed.pack = e.p;
-		oi->u.packed.is_delta = (rtype == OBJ_REF_DELTA ||
-					 rtype == OBJ_OFS_DELTA);
+
+		switch (rtype) {
+		case OBJ_REF_DELTA:
+			oi->u.packed.type = PACKED_OBJECT_TYPE_REF_DELTA;
+			break;
+		case OBJ_OFS_DELTA:
+			oi->u.packed.type = PACKED_OBJECT_TYPE_OFS_DELTA;
+			break;
+		default:
+			oi->u.packed.type = PACKED_OBJECT_TYPE_FULL;
+			break;
+		}
 	}
 
 	return 0;
@@ -2531,7 +2541,8 @@ int packfile_store_read_object_stream(struct odb_read_stream **out,
 	oi.sizep = &size;
 
 	if (packfile_store_read_object_info(store, oid, &oi, 0) ||
-	    oi.u.packed.is_delta ||
+	    oi.u.packed.type == PACKED_OBJECT_TYPE_REF_DELTA ||
+	    oi.u.packed.type == PACKED_OBJECT_TYPE_OFS_DELTA ||
 	    repo_settings_get_big_file_threshold(store->odb->repo) >= size)
 		return -1;