Fix for off-by-one bug when ATs look for next transaction. Currently configured to take effect block 275,000

src/main/java/org/qortal/at/QortalATAPI.java

@@ -146,7 +146,11 @@ public class QortalATAPI extends API {
 		String atAddress = this.atData.getATAddress();
 
 		int height = timestamp.blockHeight;
-		int sequence = timestamp.transactionSequence + 1;
+		int sequence = timestamp.transactionSequence;
+
+		if (state.getCurrentBlockHeight() < BlockChain.getInstance().getAtFindNextTransactionFixHeight())
+			// Off-by-one bug still in effect
+			sequence += 1;
 
 		ATRepository.NextTransactionInfo nextTransactionInfo;
 		try {

src/main/java/org/qortal/block/BlockChain.java

@@ -70,6 +70,7 @@ public class BlockChain {
 	private GenesisBlock.GenesisInfo genesisInfo;
 
 	public enum FeatureTrigger {
+		atFindNextTransactionFix;
 	}
 
 	/** Map of which blockchain features are enabled when (height/timestamp) */
@@ -371,6 +372,10 @@ public class BlockChain {
 
 	// Convenience methods for specific blockchain feature triggers
 
+	public int getAtFindNextTransactionFixHeight() {
+		return this.featureTriggers.get(FeatureTrigger.atFindNextTransactionFix.name()).intValue();
+	}
+
 	// More complex getters for aspects that change by height or timestamp
 
 	public long getRewardAtHeight(int ourHeight) {

src/main/resources/blockchain.json

@@ -48,6 +48,7 @@
 		"minutesPerBlock": 1
 	},
 	"featureTriggers": {
+		"atFindNextTransactionFix": 275000
 	},
 	"genesisInfo": {
 		"version": 4,