From: Eric Sunshine <sunshine@sunshineco.com>
Date: Wed, 30 Mar 2016 00:57:14 GMT
Subject: Re: [PATCH 1/6] path.c: allocate enough memory for string
Message-ID: <CAPig+cSqC1muy+vcmpkp9uM9T3CC4pa5jWGUot_FtrVshEAUEw@mail.gmail.com>
In-Reply-To: <1459298333-21899-2-git-send-email-sbeller@google.com>

On Tue, Mar 29, 2016 at 8:38 PM, Stefan Beller <sbeller@google.com> wrote:
> `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>
> ---
> diff --git 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);

Huh? This is a trie. It never accesses 'contents' as a NUL-terminated
string. Plus, no NUL is ever even copied, thus this is just
overallocating. How is this an improvement?

>         }
>         new_node->value = value;
> --