Re: [PATCH] attr.c: move ATTR_MAX_FILE_SIZE check into read_attr_from_buf()

> Ensure that we refuse to process a .gitattributes blob exceeding
> ATTR_MAX_FILE_SIZE when reading from either an arbitrary tree object or
> a sparse directory. This is done by pushing the ATTR_MAX_FILE_SIZE check
> down into the low-level `read_attr_from_buf()`.
>
> In doing so, plug a leak in `read_attr_from_index()` where we would
> accidentally leak the large buffer upon detecting it is too large to
> process.
>
> (Since `read_attr_from_buf()` handles a NULL buffer input, we can remove
> a NULL check before calling it in `read_attr_from_index()` as well).
>
> Co-authored-by: Jeff King <peff@peff.net>
> Signed-off-by: Jeff King <peff@peff.net>
> Signed-off-by: Taylor Blau <me@ttaylorr.com>
> ---