bsdflags cleanup, #6908

https://github.com/borgbackup/borg/issues/6908#issuecomment-1224839170

src/borg/archive.py

@@ -1144,8 +1144,7 @@ class MetadataCollector:
         if not self.noflags:
             with backup_io("extended stat (flags)"):
                 flags = get_flags(path, st, fd=fd)
-            if flags:
-                attrs["bsdflags"] = flags
+            attrs["bsdflags"] = flags
         if not self.noxattrs:
             with backup_io("extended stat (xattrs)"):
                 xattrs = xattr.get_all(fd or path, follow_symlinks=False)

src/borg/helpers/parseformat.py

@@ -834,7 +834,7 @@ class ItemFormatter(BaseFormatter):
         item_data["source"] = source
         item_data["linktarget"] = source
         item_data["hlid"] = hlid
-        item_data["flags"] = item.get("bsdflags", 0)
+        item_data["flags"] = item.get("bsdflags")  # int if flags known, else (if flags unknown) None
         for key in self.used_call_keys:
             item_data[key] = self.call_keys[key](item)
         return item_data