[RFA] Fix memory leak in windows_xfer_shared_libraries

[Pedro Alves]

On 12/13/2012 11:11 AM, Pierre Muller wrote:
> --- windows-nat.c       13 Nov 2012 09:46:10 -0000      1.236
> +++ windows-nat.c       13 Dec 2012 10:54:18 -0000
> @@ -2411,11 +2411,11 @@ windows_xfer_shared_libraries (struct ta
>    buf = obstack_finish (&obstack);
>    len_avail = strlen (buf);
>    if (offset >= len_avail)
> -    return 0;
> -
> -  if (len > len_avail - offset)
> +    len= 0
> +  else if (len > len_avail - offset)
>      len = len_avail - offset;
> -  memcpy (readbuf, buf + offset, len);
> +  if (len > 0)
> +    memcpy (readbuf, buf + offset, len);
> 

You can avoid the last if by writing as:

  if (offset >= len_avail)
    len = 0;
  else
    {
      if (len > len_avail - offset)
	len = len_avail - offset;
      memcpy (readbuf, buf + offset, len);
    }

I'd prefer that, but patch is okay either way.

>    obstack_free (&obstack, NULL);
>    return len;

>
>   I was also wondering if it would not be better to keep the obstack in
> between the two calls, but that would probably require some static variable
> :(

That'd be fine.  We actually do that in some cases in gdbserver, like
handle_qxfer_threads and handle_qxfer_traceframe_info.  It just didn't
look like worth it enough to bother when I initially wrote this.

-- 
Pedro Alves