Re: [PATCH v3 16/21] repack: handle optional files created by pack-objects

> We ask pack-objects to pack to a set of temporary files, and
> then rename them into place. Some files that pack-objects
> creates may be optional (like a .bitmap file), in which case
> we would not want to call rename(). We already call stat()
> and make the chmod optional if the file cannot be accessed.
> We could simply skip the rename step in this case, but that
> would be a minor regression in noticing problems with
> non-optional files (like the .pack and .idx files).
>
> Instead, we can now annotate extensions as optional, and
> skip them if they don't exist (and otherwise rely on
> rename() to barf).
>
> Signed-off-by: Jeff King <peff@peff.net>