Constrained the minimum unity fork number to 2

modAionImpl/src/org/aion/zero/impl/blockchain/AionBlockchainImpl.java

@@ -235,6 +235,11 @@ protected AionBlockchainImpl(
         this.forkUtility = new ForkUtility(); // forks are disabled by default
         Optional<Long> maybeFork050 = load050ForkNumberFromConfig(CfgAion.inst());
         if (maybeFork050.isPresent()) {
+            if (maybeFork050.get() < 2) {   // AKI-419, Constrain the minimum unity fork number
+                LOG.warn("The unity fork number cannot be less than 2, set the fork number to 2");
+                maybeFork050 = Optional.of(2L);
+            }
+
             this.forkUtility.enableUnityFork(maybeFork050.get());
         }
 

modAionImpl/test/org/aion/zero/impl/blockchain/AionBlockchainImplTest.java

@@ -0,0 +1,64 @@
+package org.aion.zero.impl.blockchain;
+
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertTrue;
+
+import java.util.Properties;
+import org.aion.zero.impl.config.CfgAion;
+import org.junit.After;
+import org.junit.Test;
+
+public class AionBlockchainImplTest {
+
+    private StandaloneBlockchain blockchain;
+
+    @After
+    public void tearDown() {
+
+        CfgAion cfg = CfgAion.inst();
+        Properties p = new Properties();
+        p.put("fork0.5.0", String.valueOf(Long.MAX_VALUE));
+        cfg.getFork().setProperties(p);
+        this.blockchain = null;
+    }
+
+    @Test
+    public void testUnityMininmumNumber() {
+        CfgAion cfg = CfgAion.inst();
+        Properties p = new Properties();
+        p.put("fork0.5.0", "1");
+        cfg.getFork().setProperties(p);
+
+        StandaloneBlockchain.Bundle bundle =
+            new StandaloneBlockchain.Builder()
+                .withDefaultAccounts()
+                .withValidatorConfiguration("simple")
+                .build();
+        this.blockchain = bundle.bc;
+
+        assertNotNull(blockchain);
+        //AKI-419 the minimum fork point is 2, therefore, the unity protocol will start from 3
+        assertFalse(blockchain.forkUtility.isUnityForkActive(2));
+        assertTrue(blockchain.forkUtility.isUnityForkActive(3));
+    }
+
+    @Test
+    public void testUnityMininmumNumber2() {
+        CfgAion cfg = CfgAion.inst();
+        Properties p = new Properties();
+        p.put("fork0.5.0", "2");
+        cfg.getFork().setProperties(p);
+
+        StandaloneBlockchain.Bundle bundle =
+            new StandaloneBlockchain.Builder()
+                .withDefaultAccounts()
+                .withValidatorConfiguration("simple")
+                .build();
+        this.blockchain = bundle.bc;
+
+        assertNotNull(blockchain);
+        assertFalse(blockchain.forkUtility.isUnityForkActive(2));
+        assertTrue(blockchain.forkUtility.isUnityForkActive(3));
+    }
+}