Fix another zero block bug with check

src/decode.c

@@ -439,7 +439,7 @@ int aec_decode(struct aec_stream *strm, int flush)
        of the states are called. Inspired by zlib.
     */
 
-    int zero_blocks;
+    int zero_blocks, b;
     int64_t gamma, beta, ms, delta1;
     int k;
     decode_state *state;
@@ -522,9 +522,8 @@ int aec_decode(struct aec_stream *strm, int flush)
             DROPFS();
 
             if (zero_blocks == ROS) {
-                zero_blocks =  64 - (
-                    (state->samples_out / strm->block_size)
-                    % strm->rsi % 64);
+                b = (state->samples_out / strm->block_size) % strm->rsi;
+                zero_blocks = MIN(strm->rsi - b, 64 - (b % 64));
             } else if (zero_blocks > ROS) {
                 zero_blocks--;
             }

src/encode.c

@@ -302,7 +302,8 @@ static int m_check_zero_block(struct aec_stream *strm)
             state->zero_ref = state->ref;
             state->zero_ref_sample = state->block_p[0];
         }
-        if ((strm->rsi - state->blocks_avail) % 64 == 0) {
+        if (state->blocks_avail == 0
+            || (strm->rsi - state->blocks_avail) % 64 == 0) {
             if (state->zero_blocks > 4)
                 state->zero_blocks = ROS;
             state->mode = m_encode_zero;

tests/check_code_options.c

@@ -9,21 +9,26 @@
 
 int check_block_sizes(struct test_state *state, int id, int id_len)
 {
-    int bs, status;
+    int bs, status, rsi, max_rsi;
 
     for (bs = 8; bs <= 64; bs *= 2) {
         state->strm->block_size = bs;
-        state->strm->rsi = state->buf_len
-            / (bs * state->byte_per_sample);
 
-        status = encode_decode(state);
-        if (status)
-            return status;
+        max_rsi = state->buf_len / (bs * state->byte_per_sample);
+        if (max_rsi > 4096)
+            max_rsi = 4096;
+
+        for (rsi = 1; rsi <= max_rsi; rsi++) {
+            state->strm->rsi = rsi;
+            status = encode_decode(state);
+            if (status)
+                return status;
 
-        if ((state->cbuf[0] >> (8 - id_len)) != id) {
-            printf("FAIL: Unexpected block of size %i created %x.\n",
-                   bs, state->cbuf[0] >> (8 - id_len));
-            return 99;
+            if ((state->cbuf[0] >> (8 - id_len)) != id) {
+                printf("FAIL: Unexpected block of size %i created ID:%x.\n",
+                       bs, state->cbuf[0] >> (8 - id_len));
+                return 99;
+            }
         }
     }
     return 0;