Avoiding repeated PVD read attempts if first reading of PVD yielded error

libisoburn/burn_wrap.c

@@ -1191,6 +1191,7 @@ int isoburn_read_iso_head(struct burn_drive *d, int lba,
  int ret, info_mode, capacity, role;
  off_t data_count, to_read;
  enum burn_disc_status s;
+ struct isoburn *o;
 
  info_mode= flag&255;
  *image_blocks= 0;
@@ -1214,6 +1215,10 @@ int isoburn_read_iso_head(struct burn_drive *d, int lba,
    }
    to_read= (off_t) capacity * ((off_t) 2048);
    if(ret > 0 && to_read >= (off_t) (36 * 1024)) {
+     ret= isoburn_find_emulator(&o, d, 0);
+     if(ret > 0)
+       if(o->media_read_error)
+         return(-1 * !!(flag & (1 << 15)));
      if(to_read >= (off_t) (64 * 1024))
        to_read= 64 * 1024;
      ret = burn_read_data(d, ((off_t) lba) * (off_t) 2048, (char *) buffer,

libisoburn/isoburn.c

@@ -135,6 +135,7 @@ int isoburn_new(struct isoburn **objpt, int flag)
  o->truncate= 0;
  o->iso_source= NULL;
  o->fabricated_disc_status= BURN_DISC_UNREADY;
+ o->media_read_error= 0;
  o->toc= NULL;
  o->wrote_well= -1;
  o->loaded_partition_offset= 0;

libisoburn/isoburn.h

@@ -113,6 +113,10 @@ struct isoburn {
  */
  enum burn_disc_status fabricated_disc_status;
 
+ /* To be set if read errors occured during media evaluation.
+ */
+ int media_read_error;
+
  /* Eventual emulated table of content read from the chain of ISO headers
     on overwriteable media.
  */ 

libisoburn/isofs_wrap.c

@@ -482,10 +482,14 @@ int isoburn_start_emulation(struct isoburn *o, int flag)
    memset(o->target_iso_head, 0, to_read);
    if(capacity > 0 && (off_t) capacity * (off_t) 2048 < to_read)
      to_read = (off_t) capacity * (off_t) 2048;
+
    ret = burn_read_data(drive, (off_t) 0, (char*)o->target_iso_head, 
-                        to_read, &data_count, 2 | 8);
+                        to_read, &data_count, 4 | 8);
+                                   /* <<< was 2 | 8); */
+
    if (ret <= 0) {
      /* an error means a disc with no ISO image */
+     o->media_read_error= 1;
      if (ret == -2) {
        path[0]= 0;
        burn_drive_d_get_adr(drive, path);

xorriso/xorriso_timestamp.h

@@ -1 +1 @@
-#define Xorriso_timestamP "2011.04.14.081721"
+#define Xorriso_timestamP "2011.04.22.081847"