Re: [PATCH 2/7] patch-delta: use size_t for sizes

[Patrick Steinhardt <ps@pks.im>]

On Thu, Jun 04, 2026 at 10:51:07AM +0000, Johannes Schindelin via GitGitGadget wrote:
> From: Johannes Schindelin <johannes.schindelin@gmx.de>
> 
> `patch_delta()` takes the source and delta sizes by value and writes
> back the reconstructed target size through an `unsigned long *`.  That
> datatype cannot represent a value that exceeds 4 GiB on systems where
> `unsigned long` is 32-bit (notably 64-bit Windows builds), though, even
> though the delta encoding itself, the on-disk layout, and the in-memory
> buffers happily carry such sizes. A `size_t` companion to
> `get_delta_hdr_size()`, `get_delta_hdr_size_sz()`, was introduced in
> 17fa077596 (delta, packfile: use size_t for delta header sizes,
> 2026-05-08) precisely so that `patch_delta()` could be widened without
> changing the on-the-wire decoding helper's signature.
> 
> Widen `patch_delta()`'s three size parameters to `size_t` and switch
> its internal use of `get_delta_hdr_size()` to the `_sz` variant.
> Then propagate the wider type through the callers.

Does `get_delta_hdr_size()` have any remaining callers after this patch
series? I currently only spot two such callers, and you convert both of
them in this patch.

And can we reasonably add a test case that exercises this change?

> diff --git a/packfile.c b/packfile.c
> index 89366abfe3..e202f48837 100644
> --- a/packfile.c
> +++ b/packfile.c
> @@ -1964,10 +1964,8 @@ void *unpack_entry(struct repository *r, struct packed_git *p, off_t obj_offset,
>  			      (uintmax_t)curpos, p->pack_name);
>  			data = NULL;
>  		} else {
> -			unsigned long sz;
>  			data = patch_delta(base, base_size, delta_data,
> -					   delta_size, &sz);
> -			size = sz;
> +					   delta_size, &size);

Nice that we get rid of this awkward construct.

Patrick