index-pack: avoid immediate object fetch while parsing packfile

Prevent packfile parsing from accidentally dynamically fetching
each individual object found in the packfile.

When index-pack parses the input packfile, it does a lookup in the
ODB to test for conflicts/collisions.  This can accidentally cause
the object to be individually fetched when gvfs-helper (or
read-object-hook or partial-clone) is enabled.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>

builtin/index-pack.c

@@ -812,7 +812,7 @@ static void sha1_object(const void *data, struct object_entry *obj_entry,
 		read_lock();
 		collision_test_needed =
 			repo_has_object_file_with_flags(the_repository, oid,
-							OBJECT_INFO_QUICK);
+							OBJECT_INFO_FOR_PREFETCH);
 		read_unlock();
 	}