What about this one?

On Thu, 02 Feb 2006 18:31:37 EET
"Sergey Poznyakoff" <[EMAIL PROTECTED]> wrote:

> Peter Vrabec <[EMAIL PROTECTED]> wrote:
> 
> > extracting a sparse file to a filesystem like vfat that does not
> > support sparse files results in an incomplete output file.
> 
> Thanks for reporting.
> 
> > What do you think about attached patch?
> 
> I think that, while the issue should certainly be solved, the patch
> addresses it the wrong way. It should be the responsibility of
> sys_truncate to handle this case.
> 
> Regards,
> Sergey
--- tar-1.15.1/src/system.c.vfatTruncate	2004-09-06 07:31:00.000000000 -0400
+++ tar-1.15.1/src/system.c	2006-02-03 14:40:51.000000000 -0500
@@ -272,8 +272,25 @@
 int
 sys_truncate (int fd)
 {
+  struct stat st;
   off_t pos = lseek (fd, (off_t) 0, SEEK_CUR);
-  return pos < 0 ? -1 : ftruncate (fd, pos);
+
+  if ( pos < 0) 
+    return -1;
+
+  if ( ftruncate (fd, pos) != 0 ) {
+    /* wrapper around ftruncate:
+     * ftruncate may fail to grow the size of a file with some OS and filesystem
+     * combinations. Linux and vfat/fat is one example. If this is the case do
+     * a write to grow the file to the desired length.
+     */
+    if( (fstat( fd, &st ) == -1) || 
+        (st.st_size >= pos)  ||
+        (lseek( fd, pos - 1, SEEK_SET) == (off_t)-1) ||
+        (write( fd, "\0", 1) == -1) )
+	return -1;
+  }
+  return 0;
 }
 
 /* Return nonzero if NAME is the name of a regular file, or if the file
_______________________________________________
Bug-tar mailing list
Bug-tar@gnu.org
http://lists.gnu.org/mailman/listinfo/bug-tar

Reply via email to