Re: [PATCH 1/6] path.c: allocate enough memory for string

From: Junio C Hamano <gitster@pobox.com>
Date: Mar 30, 2016, 00:56 UTC
Message-ID: <xmqq7fgkvl47.fsf@gitster.mtv.corp.google.com>
In-Reply-To: <1459298333-21899-2-git-send-email-sbeller@google.com>

Stefan Beller <sbeller@google.com> writes:

Show 21 quoted lines

> `strlen` returns the length of a string without the terminating null byte.
> To make sure enough memory is allocated we need to pass `strlen(..) + 1`
> to the allocation function.
>
> Signed-off-by: Stefan Beller <sbeller@google.com>
> ---
>  path.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/path.c b/path.c
> index 969b494..0ae8af5 100644
> --- a/path.c
> +++ b/path.c
> @@ -155,7 +155,7 @@ static struct trie *make_trie_node(const char *key, void *value)
>  	struct trie *new_node = xcalloc(1, sizeof(*new_node));
>  	new_node->len = strlen(key);
>  	if (new_node->len) {
> -		new_node->contents = xmalloc(new_node->len);
> +		new_node->contents = xmalloc(new_node->len + 1);
>  		memcpy(new_node->contents, key, new_node->len);
>  	}

This structure looks like a counted string <len,ptr> that does not want to have a terminating NUL after the contents, judging from the way memcpy() copies only len and not len+1.

Did I write this (wondering why this was addressed to me)?

>  	new_node->value = value;