Re: [PATCH] strbuf: allocate enough space when strbuf_setlen() is called first time
- From
Junio C Hamano <gitster@pobox.com>
- Date
- Apr 26, 2011, 15:25 UTC
- Message-ID
- <7v7hahghls.fsf@alter.siamese.dyndns.org>
- In-Reply-To
- <1303820660-744-1-git-send-email-pclouds@gmail.com>
Nguyễn Thái Ngọc Duy <pclouds@gmail.com> writes:
Show 19 quoted lines
> strbuf_grow(sb, 0) may allocate less than requested len and violate the
> next assertion.
>
> Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
> ---
> strbuf.h | 2 +-
> 1 files changed, 1 insertions(+), 1 deletions(-)
>
> diff --git a/strbuf.h b/strbuf.h
> index 07060ce..ab213da 100644
> --- a/strbuf.h
> +++ b/strbuf.h
> @@ -34,7 +34,7 @@ extern void strbuf_grow(struct strbuf *, size_t);
>
> static inline void strbuf_setlen(struct strbuf *sb, size_t len) {
> if (!sb->alloc)
> - strbuf_grow(sb, 0);
> + strbuf_grow(sb, len);
> assert(len < sb->alloc);This looks so obviously correct that it is scary.
How could 60 callsites of this function manage to have run without crashes so far? They all happen to use the function on a buffer that already has something on it?
Well spotted, thanks.