Fix wrong recent sealers management

Author: bunnie307

bmv/bsc2/src/main/java/foundation/icon/btp/bmv/bsc2/BTPMessageVerifier.java

@@ -45,7 +45,7 @@ public class BTPMessageVerifier implements BMV {
 
     public BTPMessageVerifier(Address _bmc, BigInteger _chainId, @Optional byte[] _header,
                               @Optional byte[] _validators, @Optional byte[] _candidates,
-                              @Optional byte[] _recents, @Optional Integer _currTurnLength, @Optional Integer _nextTurnLength) {
+                              @Optional byte[] _recents, @Optional int _currTurnLength, @Optional int _nextTurnLength) {
         ChainConfig config = ChainConfig.setChainID(_chainId);
         if (_header != null) {
             Header head = Header.fromBytes(_header);
@@ -54,13 +54,14 @@ public BTPMessageVerifier(Address _bmc, BigInteger _chainId, @Optional byte[] _h
             MerkleTreeAccumulator mta = new MerkleTreeAccumulator(head.getNumber().longValueExact());
             mta.add(head.getHash().toBytes());
 
+            Context.require(_currTurnLength > 0 && _nextTurnLength > 0, "Invalid turn lengths");
             Validators validators = Validators.fromBytes(_validators);
             EthAddresses recents = EthAddresses.fromBytes(_recents);
             if (head.getNumber().compareTo(BigInteger.ZERO) == 0) {
                 Context.require(recents.size() == 1, "Wrong recent signers");
             } else {
-                Context.require(recents.size() == validators.size() / 2 + 1,
-                        "Wrong recent signers - validators/2+1");
+                Context.require(recents.size() == Utils.calcMinerHistoryLength(validators.size(),
+                            _currTurnLength) + 1, "Wrong recent signer counts");
             }
 
             this.bmc.set(_bmc);
@@ -84,7 +85,7 @@ public BTPMessageVerifier(Address _bmc, BigInteger _chainId, @Optional byte[] _h
 
     @External(readonly = true)
     public String getVersion() {
-        return "0.7.1";
+        return "0.7.2";
     }
 
     @External(readonly = true)

bmv/bsc2/src/main/java/foundation/icon/btp/bmv/bsc2/Snapshot.java

@@ -96,7 +96,7 @@ public Snapshot apply(ChainConfig config, Header head) {
         Context.require(validators.contains(sealer), "UnauthorizedValidator");
 
         EthAddresses newRecents = new EthAddresses(recents);
-        if (newNumber.longValue() >= getMinerHistoryLength() + 1 && newRecents.size() > 0) {
+        if (newRecents.size() >= getMinerHistoryLength() + 1) {
             newRecents.remove(0);
         }
 
@@ -123,18 +123,19 @@ public Snapshot apply(ChainConfig config, Header head) {
         if (newNumber.longValue() % config.Epoch == getMinerHistoryLength()) {
             newCurrTurnLength = nextTurnLength;
             newValidators = candidates;
+
+            // If the number of current validators is less than the number of previous validators,
+            // the capacity of the recent signers should be adjusted
+            int limit = Utils.calcMinerHistoryLength(newValidators.size(), newCurrTurnLength) + 1;
+            for (int i = 0; i < newRecents.size() - limit; i++) {
+                newRecents.remove(i);
+            }
+
             if (config.isBohr(head.getTime())) {
                 // BEP-404: Clear Miner History when switching validators set
                 for (int i = 0; i < newRecents.size(); i++) {
                     newRecents.set(i, EthAddress.EMPTY);
                 }
-            } else {
-                // If the number of current validators is less than the number of previous validators,
-                // the capacity of the recent signers should be adjusted
-                int limit = newValidators.size() / 2;
-                for (int i = 0; i < newRecents.size() - limit; i++) {
-                    newRecents.remove(i);
-                }
             }
         }
         if (newNumber.longValue() % config.Epoch == (long) (voters.size() / 2 + 1) * currTurnLength) {
@@ -146,7 +147,7 @@ public Snapshot apply(ChainConfig config, Header head) {
     }
 
     public int getMinerHistoryLength() {
-        return (validators.size() / 2 + 1) * currTurnLength - 1;
+        return Utils.calcMinerHistoryLength(validators.size(), currTurnLength);
     }
 
     public boolean isRecentlySigned(EthAddress signer) {

bmv/bsc2/src/main/java/foundation/icon/btp/bmv/bsc2/Utils.java

@@ -2,6 +2,10 @@
 
 public class Utils {
 
+    public static int calcMinerHistoryLength(int nvals, int nturns) {
+        return (nvals / 2 + 1) * nturns - 1;
+    }
+
     public static int ceilDiv(int x, int y) {
         if (y == 0) {
             return 0;

bmv/bsc2/src/test/java/foundation/icon/btp/bmv/bsc2/BMVTest.java

@@ -36,7 +36,7 @@ public static void handleRelayMessageTest(DataSource.Case c, Score bmv, String p
             byte[][] ret = (byte[][]) sm.call(BMC, BigInteger.ZERO, bmv.getAddress(), "handleRelayMessage",
                     BMC_BTP_ADDR.toString(), prev, BigInteger.valueOf(0), p.getMessage());
 
-            if (p.getResult().size() > 0) {
+            if (!p.getResult().isEmpty()) {
                 assertEquals(p.getResult().size(), ret.length);
                 for (int i=0; i<p.getResult().size(); i++) {
                     assertEquals(p.getResult().get(i), new String(ret[i]));

bmv/bsc2/src/test/java/foundation/icon/btp/bmv/bsc2/DataSource.java

@@ -61,8 +61,8 @@ public static class Deployment {
             private String validators;
             private String candidates;
             private String recents;
-            private Integer currTurnLength;
-            private Integer nextTurnLength;
+            private int currTurnLength;
+            private int nextTurnLength;
 
             public byte[] getHeader() {
                 return StringUtil.hexToBytes(header);