Re: [PATCH 4/6] delta, packfile: use size_t for delta header sizes

[Johannes Schindelin <Johannes.Schindelin@gmx.de>]

Hi Stolee,

On Sun, 3 May 2026, Derrick Stolee wrote:

> On 4/28/26 12:26 PM, Johannes Schindelin via GitGitGadget wrote:
> > From: Johannes Schindelin <johannes.schindelin@gmx.de>
> > 
> > The delta header decoding functions return unsigned long, which
> > truncates on Windows for objects larger than 4GB. Introduce size_t
> > variants get_delta_hdr_size_sz() and get_size_from_delta_sz() that
> > preserve the full 64-bit size, and use them in packed_object_info()
> > where the size is needed for streaming decisions.
> 
> > + * Size_t variant that doesn't truncate - use for >4GB objects on Windows.
> > + */
> > +static inline size_t get_delta_hdr_size_sz(const unsigned char **datap,
> > +					   const unsigned char *top)
> ...
> > +static inline unsigned long get_delta_hdr_size(const unsigned char **datap,
> > +					       const unsigned char *top)
> > +{
> > +	size_t size = get_delta_hdr_size_sz(datap, top);
> >   	return cast_size_t_to_ulong(size);
> >   }
> 
> I like this trick to use the 64-bit implementation and only to
> down-cast for API compatibility. This allows a more gradual
> transition than if we replaced ulongs with size_ts everywhere
> at once.

Thank you! That was indeed the exact thing I wanted to achieve: To allow
for incremental, easy-to-review patch series.

Ciao,
Johannes