libdvdread: backport upstream changesets r1232 and r1234.

This fixes playback of some discs that have been recently reported as failing.

mythtv/libs/libmythdvdnav/dvdread/dvd_udf.c

@@ -333,16 +333,17 @@ static int SetUDFCache(dvd_reader_t *device, UDFCacheType type,
 static int Unicodedecode( uint8_t *data, int len, char *target )
 {
   int p = 1, i = 0;
+  int err = 0;
 
   if( ( data[ 0 ] == 8 ) || ( data[ 0 ] == 16 ) ) do {
-    if( data[ 0 ] == 16 ) p++;  /* Ignore MSB of unicode16 */
+    if( data[ 0 ] == 16 ) err |= data[p++];  /* character cannot be converted to 8bit, return error */
     if( p < len ) {
       target[ i++ ] = data[ p++ ];
     }
   } while( p < len );
 
   target[ i ] = '\0';
-  return 0;
+  return !err;
 }
 
 static int UDFDescriptor( uint8_t *data, uint16_t *TagID )
@@ -494,8 +495,9 @@ static int UDFFileIdentifier( uint8_t *data, uint8_t *FileCharacteristics,
   L_FI = GETN1(19);
   UDFLongAD(&data[20], FileICB);
   L_IU = GETN2(36);
-  if (L_FI) Unicodedecode(&data[38 + L_IU], L_FI, FileName);
-  else FileName[0] = '\0';
+  if (L_FI) {
+    if (!Unicodedecode(&data[38 + L_IU], L_FI, FileName)) FileName[0] = 0;
+  } else FileName[0] = '\0';
   return 4 * ((38 + L_FI + L_IU + 3) / 4);
 }
 

mythtv/libs/libmythdvdnav/dvdread/ifo_read.c

@@ -1191,6 +1191,10 @@ int ifoRead_VTS_PTT_SRPT(ifo_handle_t *ifofile) {
     return 0;
   }
 
+  if(vts_ptt_srpt->nr_of_srpts > info_length / sizeof(*data)) {
+    fprintf(stderr, "libdvdread: PTT search table too small.\n");
+    goto fail;
+  }
   for(i = 0; i < vts_ptt_srpt->nr_of_srpts; i++) {
     B2N_32(data[i]);
     /* assert(data[i] + sizeof(ptt_info_t) <= vts_ptt_srpt->last_byte + 1);