[Libcdio-devel] [PATCH] cdtext: Count empty fields as tracks

[John Ernberg]

The following CD-TEXT would fail when parsing due to an off-by-one in
the composer data type because the album-level composer field is empty:

    80 0 0 0 41 20 4d 65 6d 6f 69 72 20 6f 66 20 5f 23
    80 0 1 c 46 72 65 65 20 57 69 6c 6c 0 47 6f 5b 8d
    80 1 2 2 6e 65 20 42 75 74 20 4e 6f 74 20 46 b0 df
    80 1 3 e 6f 72 67 6f 74 74 65 6e 0 49 6e 73 9 18
    80 2 4 3 61 6e 69 74 79 20 41 20 4d 6f 6e 69 49 27
    80 2 5 f 6b 65 72 20 4f 66 20 4d 65 0 54 6f 13 d2
    80 3 6 2 20 50 65 72 73 69 73 74 20 6f 72 20 3b 87
    80 3 7 e 41 64 68 65 72 65 0 41 6e 20 45 6c 63 87
    80 4 8 5 65 67 79 20 66 6f 72 20 61 20 4d 61 bc e6
    80 4 9 f 6e 20 41 6c 69 76 65 0 50 73 79 63 93 89
    80 5 a 4 68 6f 74 69 63 6c 79 73 6d 0 41 6e d6 a
    80 6 b 2 20 49 6e 74 72 61 6d 75 72 61 6c 20 aa b6
    80 6 c e 4d 61 64 6e 65 73 73 0 51 75 65 73 b8 0
    80 7 d 4 74 69 6f 6e 73 20 6f 66 20 61 20 48 60 11
    80 7 e f 6f 6c 69 73 74 69 63 20 44 69 76 69 bb b8
    80 7 f f 6e 65 0 57 69 74 68 20 56 69 72 74 60 f5
    80 8 10 9 75 65 20 49 20 41 6d 20 46 72 65 65 21 6
    80 8 11 f 0 42 61 74 74 6c 65 73 20 41 72 65 a5 b9
    80 9 12 b 20 57 6f 6e 20 57 69 74 68 69 6e 0 b0 f3
    80 a 13 0 41 20 4d 65 6d 69 6f 72 20 6f 66 20 52 2f
    80 a 14 c 46 72 65 65 20 57 69 6c 6c 0 0 0 78 30
    81 0 15 0 4b 72 6f 73 69 73 0 4b 72 6f 73 69 91 f1
    81 1 16 5 73 0 9 0 9 0 9 0 9 0 9 0 80 2d
    81 7 17 0 9 0 9 0 9 0 9 0 0 0 0 0 bd f4
    82 0 18 0 0 4b 72 6f 73 69 73 0 9 0 9 0 47 9c
            ^^^
    82 4 19 0 9 0 9 0 9 0 9 0 9 0 9 0 1f 7f
    82 a 1a 0 9 0 0 0 0 0 0 0 0 0 0 0 1e f8
    83 0 1b 0 0 4b 72 6f 73 69 73 0 9 0 9 0 62 1b
    83 4 1c 0 9 0 9 0 9 0 9 0 9 0 9 0 31 9f
    83 a 1d 0 9 0 0 0 0 0 0 0 0 0 0 0 c6 da
    84 0 1e 0 0 4b 72 6f 73 69 73 0 9 0 9 0 8c 40
    84 4 1f 0 9 0 9 0 9 0 9 0 9 0 9 0 d4 a3
    84 a 20 0 9 0 0 0 0 0 0 0 0 0 0 0 98 d2
    8e 0 21 0 0 51 4d 37 32 38 31 39 30 35 32 30 2c cb
    8e 1 22 b 34 0 51 4d 37 32 38 31 39 30 35 32 31 28
    8e 2 23 a 30 35 0 51 4d 37 32 38 31 39 30 35 1a 5c
    8e 3 24 9 32 30 36 0 51 4d 37 32 38 31 39 30 53 af
    8e 4 25 8 35 32 30 37 0 51 4d 37 32 38 31 39 6c 0
    8e 5 26 7 30 35 32 30 38 0 51 4d 37 32 38 31 c6 9b
    8e 6 27 6 39 30 35 32 30 39 0 51 4d 37 32 38 39 e0
    8e 7 28 5 31 39 30 35 32 31 30 0 51 4d 37 32 48 67
    8e 8 29 4 38 31 39 30 35 32 31 31 0 51 4d 37 bf 19
    8e 9 2a 3 32 38 31 39 30 35 32 31 32 0 51 4d 17 fa
    8e a 2b 2 37 32 38 31 39 30 35 32 31 33 0 0 6f 43
    8f 0 2c 0 0 1 a 0 15 3 3 3 3 0 0 0 5f 7b
    8f 1 2d 0 0 0 0 0 0 0 b 3 2e 0 0 0 68 6c
    8f 2 2e 0 0 0 0 0 9 0 0 0 0 0 0 0 e7 87

With the album-level field empty cur_track was never incremented,
causing an off-by-one. Since the CD-TEXT additionally makes use of the
Tab Indicator the entire CD-TEXT is thrown out as invalid due to a tab
found in track 1 (that should be track 2).

Fix this by always incrementing cur_track on a termination, even if the
buffer contains nothing.

Since this may cause cur_track to go beyond the last track of the CD
setting the CD-TEXT fields is now guarded by the total track count.
---

Hi,

Please note I did not subscribe to the list, please explicitly include
me in responses.

Thanks!

---

 lib/driver/cdtext.c | 68 +++++++++++++++++++++++----------------------
 1 file changed, 35 insertions(+), 33 deletions(-)

diff --git a/lib/driver/cdtext.c b/lib/driver/cdtext.c
index a80d5974..85af1836 100644
--- a/lib/driver/cdtext.c
+++ b/lib/driver/cdtext.c
@@ -799,7 +799,7 @@ cdtext_data_init(cdtext_t *p_cdtext, uint8_t
*wdata, size_t i_data)
             buffer[i_buf++] = pack.text[j];
             if(pack.db_chars)
               buffer[i_buf++] = pack.text[j+1];
-          } else if(i_buf > 0) {
+          } else {
             /* if end of string */

             /* check if the buffer contains only the Tab Indicator */
@@ -815,38 +815,40 @@ cdtext_data_init(cdtext_t *p_cdtext, uint8_t
*wdata, size_t i_data)
                 buffer[i_buf++] = 0;
             }

-            switch (pack.type) {
-              case CDTEXT_PACK_TITLE:
-                cdtext_set(p_cdtext, CDTEXT_FIELD_TITLE, buffer,
cur_track, charset);
-                break;
-              case CDTEXT_PACK_PERFORMER:
-                cdtext_set(p_cdtext, CDTEXT_FIELD_PERFORMER, buffer,
cur_track, charset);
-                break;
-              case CDTEXT_PACK_SONGWRITER:
-                cdtext_set(p_cdtext, CDTEXT_FIELD_SONGWRITER, buffer,
cur_track, charset);
-                break;
-              case CDTEXT_PACK_COMPOSER:
-                cdtext_set(p_cdtext, CDTEXT_FIELD_COMPOSER, buffer,
cur_track, charset);
-                break;
-              case CDTEXT_PACK_ARRANGER:
-                cdtext_set(p_cdtext, CDTEXT_FIELD_ARRANGER, buffer,
cur_track, charset);
-                break;
-              case CDTEXT_PACK_MESSAGE:
-                cdtext_set(p_cdtext, CDTEXT_FIELD_MESSAGE, buffer,
cur_track, charset);
-                break;
-              case CDTEXT_PACK_DISCID:
-                if (cur_track == 0)
-                  cdtext_set(p_cdtext, CDTEXT_FIELD_DISCID, buffer,
cur_track, NULL);
-                break;
-              case CDTEXT_PACK_GENRE:
-                cdtext_set(p_cdtext, CDTEXT_FIELD_GENRE, buffer,
cur_track, "ASCII");
-                break;
-              case CDTEXT_PACK_UPC:
-                if (cur_track == 0)
-                  cdtext_set(p_cdtext, CDTEXT_FIELD_UPC_EAN, buffer,
cur_track, "ASCII");
-                else
-                  cdtext_set(p_cdtext, CDTEXT_FIELD_ISRC, buffer,
cur_track, "ISO-8859-1");
-                break;
+            if ( cur_track <= blocksize.i_last_track ) {
+              switch (pack.type) {
+                case CDTEXT_PACK_TITLE:
+                  cdtext_set(p_cdtext, CDTEXT_FIELD_TITLE, buffer,
cur_track, charset);
+                  break;
+                case CDTEXT_PACK_PERFORMER:
+                  cdtext_set(p_cdtext, CDTEXT_FIELD_PERFORMER,
buffer, cur_track, charset);
+                  break;
+                case CDTEXT_PACK_SONGWRITER:
+                  cdtext_set(p_cdtext, CDTEXT_FIELD_SONGWRITER,
buffer, cur_track, charset);
+                  break;
+                case CDTEXT_PACK_COMPOSER:
+                  cdtext_set(p_cdtext, CDTEXT_FIELD_COMPOSER, buffer,
cur_track, charset);
+                  break;
+                case CDTEXT_PACK_ARRANGER:
+                  cdtext_set(p_cdtext, CDTEXT_FIELD_ARRANGER, buffer,
cur_track, charset);
+                  break;
+                case CDTEXT_PACK_MESSAGE:
+                  cdtext_set(p_cdtext, CDTEXT_FIELD_MESSAGE, buffer,
cur_track, charset);
+                  break;
+                case CDTEXT_PACK_DISCID:
+                  if (cur_track == 0)
+                    cdtext_set(p_cdtext, CDTEXT_FIELD_DISCID, buffer,
cur_track, NULL);
+                  break;
+                case CDTEXT_PACK_GENRE:
+                  cdtext_set(p_cdtext, CDTEXT_FIELD_GENRE, buffer,
cur_track, "ASCII");
+                  break;
+                case CDTEXT_PACK_UPC:
+                  if (cur_track == 0)
+                    cdtext_set(p_cdtext, CDTEXT_FIELD_UPC_EAN,
buffer, cur_track, "ASCII");
+                  else
+                    cdtext_set(p_cdtext, CDTEXT_FIELD_ISRC, buffer,
cur_track, "ISO-8859-1");
+                  break;
+              }
             }
             i_buf = 0;
             ++cur_track;
-- 
2.45.1