Subject: Re: [BUG] git diff --no-index segfaults on large files (NULL object database)

From: Tian Yuchen <[email-masked]>
Date: Sun, 5 Apr 2026 01:07:27 +0800

On 4/5/26 00:53, Luca Stefani wrote:
> Thanks for looking into it.
> Locally, I simply check against null storage and it works just fine,
> flags is always 0 in my experiments so a check against
> INDEX_WRITE_OBJECT also worked.
> 
> diff --git a/object-file.c b/object-file.c
> index f0b029ff0b..68303aa99c 100644
> --- a/object-file.c
> +++ b/object-file.c
> @@ -1654,7 +1654,8 @@ int index_fd(struct index_state *istate, struct
> object_id *oid,
>    } else if ((st->st_size >= 0 &&
>        (size_t)st->st_size <=
> repo_settings_get_big_file_threshold(istate->repo)) ||
>       type != OBJ_BLOB ||
> -    (path && would_convert_to_git(istate, path))) {
> +    (path && would_convert_to_git(istate, path)) ||
> +    !(flags & INDEX_WRITE_OBJECT)) {
>    ret = index_core(istate, oid, fd, xsize_t(st->st_size),
>    type, path, flags);
>    } else {
> 
> Luca.

That looks good, almost exactly what I was about to send. I was 
mistaken— there isn’t a hash_write_object flag after all ;-)

It looks like this is your first time posting on the Git mailing list. 
Would you consider contributing this (as a patch)?

Thanks! Yuchen