From: Patrick Steinhardt <ps@pks.im>
Date: Wed, 21 Oct 2026 11:24:36 GMT
Subject: Re: [PATCH 2/3] diff: use size_t for the allocation size of word-diff buffers
Message-ID: <atig9JAm_d-1CE0p@pks.im>
In-Reply-To: <20261021101640.329990-3-gitter.spiros@gmail.com>

On Wed, Oct 21, 2026 at 12:16:38PM +0200, Elia Pinto wrote:
> diff --git a/diff.c b/diff.c
> index b4ac17f8ef..9483931c05 100644
> --- a/diff.c
> +++ b/diff.c
> @@ -1959,7 +1959,7 @@ static void emit_rewrite_diff(const char *name_a,
>  
>  struct diff_words_buffer {
>  	mmfile_t text;
> -	unsigned long alloc;
> +	size_t alloc;
>  	struct diff_words_orig {
>  		const char *begin, *end;
>  	} *orig;
> @@ -2192,7 +2192,7 @@ static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
>  		regex_t *word_regex)
>  {
>  	int i, j;
> -	long alloc = 0;
> +	size_t alloc = 0;

This is especially offending. I double checked that we really don't make
use of a potential negative value, but all this is ever used for is
`ALLOC_GROW()`.

Patrick