Hi, Pär. I got a few comments inline.
On 21 October 2014 05:47, Pär Karlsson <[email protected]> wrote:
> Whoops, I realised I failed on the GNU coding standards, please disregard
> the last one; the patch below should be better.
>
> My apologies :-/
>
> /Pär
>
> diff --git a/src/ChangeLog b/src/ChangeLog
> index d5aeca0..87abd85 100644
> --- a/src/ChangeLog
> +++ b/src/ChangeLog
> @@ -1,3 +1,8 @@
> +2014-10-20 Pär Karlsson <[email protected]>
> +
> + * utils.c (concat_strings): got rid of double loop, cleaned up
> potential
> + memory corruption if concat_strings was called with more than five
> args
> +
> 2014-10-16 Tim Ruehsen <[email protected]>
>
> * url.c (url_parse): little code cleanup
> diff --git a/src/utils.c b/src/utils.c
> index 78c282e..5f359e0 100644
> --- a/src/utils.c
> +++ b/src/utils.c
> @@ -356,42 +356,36 @@ char *
> concat_strings (const char *str0, ...)
> {
> va_list args;
> - int saved_lengths[5]; /* inspired by Apache's apr_pstrcat */
> char *ret, *p;
>
> const char *next_str;
> - int total_length = 0;
> - size_t argcount;
> + size_t len;
> + size_t total_length = 0;
> + size_t charsize = sizeof (char);
I am not sure here. Do we always assume sizeof(char) to be 1 for
platforms supported by wget?
> + size_t chunksize = 64;
> + size_t bufsize = 64;
> +
> + p = ret = xmalloc (charsize * bufsize);
>
> /* Calculate the length of and allocate the resulting string. */
>
> - argcount = 0;
> va_start (args, str0);
> for (next_str = str0; next_str != NULL; next_str = va_arg (args, char *))
> {
> - int len = strlen (next_str);
> - if (argcount < countof (saved_lengths))
> - saved_lengths[argcount++] = len;
> + len = strlen (next_str);
> + if (len == 0)
> + continue;
> total_length += len;
> - }
> - va_end (args);
> - p = ret = xmalloc (total_length + 1);
> -
> - /* Copy the strings into the allocated space. */
> -
> - argcount = 0;
> - va_start (args, str0);
> - for (next_str = str0; next_str != NULL; next_str = va_arg (args, char *))
> - {
> - int len;
> - if (argcount < countof (saved_lengths))
> - len = saved_lengths[argcount++];
> - else
> - len = strlen (next_str);
> + if (total_length > bufsize)
> + {
> + bufsize += chunksize;
Should be `bufsize = total_length` ?
> + ret = xrealloc (ret, charsize * bufsize);
> + }
> memcpy (p, next_str, len);
Xrealloc may return a new block different from p, so memcpy(p, ...)
may not be what you want.
> p += len;
> }
> va_end (args);
> + ret = xrealloc (ret, charsize * total_length + 1);
> *p = '\0';
Malloc takes time. How about counting total_length in one loop and
doing the copy in another?
Regards.
yousong
>
> return ret;
>
