Re: CMake 2.4.7-1 ready

[Bill Hoffman <bill dot hoffman at kitware dot com>]

Brian Dessent wrote:
> No, nothing's changed in the untar code in forever.  I debugged it and
> the problem is that setup does not recognise the file as a valid tar
> archive.  What version of tar did you use to create it?
>
> The problem is the 'magic' field of the tar header (offset 257).  Setup
> expects this to contain "ustar" followed by two spaces and a trailing
> NUL:
>
>     62    if (original->peek (magic, longest_magic) > 0)
>     63      {
>     64        if (memcmp (&magic[257], "ustar\040\040\0", 8) == 0)
>     65          {
>     66            /* tar */
>     67            archive_tar *rv = new archive_tar (original);
>     68            if (!rv->error ())
>     69              return rv;
>     70            return NULL;
>     71          }
>   
OK, I looked at the libtar code and found this:
 if (t->options & TAR_GNU)
   strncpy(t->th_buf.magic, "ustar  ", 8);
 else
 {
   strncpy(t->th_buf.version, TVERSION, TVERSLEN);
   strncpy(t->th_buf.magic, TMAGIC, TMAGLEN);
 }

#define  TMAGIC    "ustar"  /* ustar and a null */
#define  TMAGLEN    6
#define  TVERSION  "00"  /* 00 and no null */
#define  TVERSLEN  2

So, that explains why the tar file works, it is just not a gnu tar file.  
Something must have changed in my code because the 2.4.6 version
has the gnu style header and the 2.4.7 version has the other header.
I will try and figure out what changed and create a new release.

-Bill