Don't report empty results (if short decode fails).

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

src/wmget.cc

@@ -796,7 +796,8 @@ public:
             float decode_error = 0;
             vector<int> bit_vec = code_decode_soft (sync_score.block_type, normalize_soft_bits (raw_bit_vec), &decode_error);
 
-            result_set.add_pattern (sync_score, bit_vec, decode_error, ResultSet::Type::BLOCK);
+            if (!bit_vec.empty())
+              result_set.add_pattern (sync_score, bit_vec, decode_error, ResultSet::Type::BLOCK);
             total_count += 1;
 
             /* ---- update "all" pattern ---- */
@@ -821,9 +822,12 @@ public:
                     ab_bits[i * 2 + 1] = ab_raw_bit_vec[1][i];
                   }
                 vector<int> bit_vec = code_decode_soft (ConvBlockType::ab, normalize_soft_bits (ab_bits), &decode_error);
-                score_ab.index = sync_score.index;
-                score_ab.quality = (ab_quality[0] + ab_quality[1]) / 2;
-                result_set.add_pattern (score_ab, bit_vec, decode_error, ResultSet::Type::BLOCK);
+                if (!bit_vec.empty())
+                  {
+                    score_ab.index = sync_score.index;
+                    score_ab.quality = (ab_quality[0] + ab_quality[1]) / 2;
+                    result_set.add_pattern (score_ab, bit_vec, decode_error, ResultSet::Type::BLOCK);
+                  }
               }
             last_block_type = sync_score.block_type;
           }
@@ -842,7 +846,8 @@ public:
         float decode_error = 0;
         vector<int> bit_vec = code_decode_soft (ConvBlockType::ab, soft_bit_vec, &decode_error);
 
-        result_set.add_pattern (score_all, bit_vec, decode_error, ResultSet::Type::ALL);
+        if (!bit_vec.empty())
+          result_set.add_pattern (score_all, bit_vec, decode_error, ResultSet::Type::ALL);
       }
 
     debug_sync_frame_count = frame_count (wav_data);
@@ -945,10 +950,12 @@ class ClipDecoder
 
             float decode_error = 0;
             vector<int> bit_vec = code_decode_soft (ConvBlockType::ab, normalize_soft_bits (raw_bit_vec), &decode_error);
-
-            SyncFinder::Score sync_score_nopad = sync_score;
-            sync_score_nopad.index = time_offset_sec * wav_data.sample_rate();
-            result_set.add_pattern (sync_score_nopad, bit_vec, decode_error, ResultSet::Type::CLIP);
+            if (!bit_vec.empty())
+              {
+                SyncFinder::Score sync_score_nopad = sync_score;
+                sync_score_nopad.index = time_offset_sec * wav_data.sample_rate();
+                result_set.add_pattern (sync_score_nopad, bit_vec, decode_error, ResultSet::Type::CLIP);
+              }
           }
       }
   }