New API function isoburn_prepare_blind_grow() for -as mkisofs -multi

libisoburn/burn_wrap.c

@@ -625,6 +625,23 @@ int isoburn_disc_track_lba_nwa(struct burn_drive *d,
 }
 
 
+int isoburn_get_msc2(struct isoburn *o,
+                     struct burn_write_opts *opts, int *msc2, int flag)
+{
+ int ret, lba, nwa;
+
+ if(o->fabricated_msc2>=0)
+   *msc2= o->fabricated_msc2;
+ else {
+   ret= isoburn_disc_track_lba_nwa(o->drive, opts, 0, &lba, &nwa);
+   if(ret<=0)
+     return(ret);
+   *msc2= nwa;
+ }
+ return(1);
+}
+
+
 void isoburn_disc_write(struct burn_write_opts *opts, struct burn_disc *disc)
 {
  int ret;