Fix all pattern normalization if only A (or only B) blocks are found.

Signed-off-by: Stefan Westerfeld <stefan@space.twc.de>

src/audiowmark.cc

@@ -1202,8 +1202,8 @@ decode_and_report (const WavData& wav_data, const string& orig_pattern)
     {
       for (size_t i = 0; i < raw_bit_vec_all.size(); i += 2)
         {
-          raw_bit_vec_all[i]     /= raw_bit_vec_norm[0]; /* normalize A soft bits with number of A blocks */
-          raw_bit_vec_all[i + 1] /= raw_bit_vec_norm[1]; /* normalize B soft bits with number of B blocks */
+          raw_bit_vec_all[i]     /= max (raw_bit_vec_norm[0], 1); /* normalize A soft bits with number of A blocks */
+          raw_bit_vec_all[i + 1] /= max (raw_bit_vec_norm[1], 1); /* normalize B soft bits with number of B blocks */
         }
 
       vector<float> soft_bit_vec = normalize_soft_bits (raw_bit_vec_all);