Fix off-by-one error when reducing account level during block orphaning.

Added test to cover above.

Modified test-chain-v2.json so Dilbert starts with level 5, not 8,
to reduce number of blocks minted during tests.

src/main/java/org/qora/account/Account.java

@@ -192,6 +192,17 @@ public class Account {
 
 	// Minting blocks
 
+	/** Returns whether account can be considered a "minting account".
+	 * <p>
+	 * To be considered a "minting account", the account needs to pass at least one of these tests:<br>
+	 * <ul>
+	 * <li>account's level is at least <tt>minAccountLevelToMint</tt> from blockchain config</li>
+	 * <li>account has 'founder' flag set</li>
+	 * </ul>
+	 * 
+	 * @return true if account can be considered "minting account"
+	 * @throws DataException
+	 */
 	public boolean canMint() throws DataException {
 		Integer level = this.getLevel();
 		if (level != null && level >= BlockChain.getInstance().getMinAccountLevelToMint())
@@ -203,6 +214,17 @@ public class Account {
 		return false;
 	}
 
+	/** Returns whether account can build reward-shares.
+	 * <p>
+	 * To be able to create reward-shares, the account needs to pass at least one of these tests:<br>
+	 * <ul>
+	 * <li>account's level is at least <tt>minAccountLevelToRewardShare</tt> from blockchain config</li>
+	 * <li>account has 'founder' flag set</li>
+	 * </ul>
+	 * 
+	 * @return true if account can be considered "minting account"
+	 * @throws DataException
+	 */
 	public boolean canRewardShare() throws DataException {
 		Integer level = this.getLevel();
 		if (level != null && level >= BlockChain.getInstance().getMinAccountLevelToRewardShare())

src/main/java/org/qora/block/Block.java

@@ -1584,7 +1584,7 @@ public class Block {
 
 			final int effectiveBlocksMinted = cumulativeBlocksByLevel.get(accountData.getInitialLevel()) + accountData.getBlocksMinted();
 
-			for (int newLevel = maximumLevel; newLevel > 0; --newLevel)
+			for (int newLevel = maximumLevel; newLevel >= 0; --newLevel)
 				if (effectiveBlocksMinted >= cumulativeBlocksByLevel.get(newLevel)) {
 					if (newLevel < accountData.getLevel()) {
 						// Account has decreased in level!

src/test/java/org/qora/test/common/BlockUtils.java

@@ -46,4 +46,21 @@ public class BlockUtils {
 			orphanLastBlock(repository);
 	}
 
+	public static void orphanToBlock(Repository repository, int targetHeight) throws DataException {
+		do {
+			BlockData blockData = repository.getBlockRepository().getLastBlock();
+			final int height = blockData.getHeight();
+
+			if (height <= targetHeight)
+				return;
+
+			Block block = new Block(repository, blockData);
+			block.orphan();
+
+			LOGGER.info(String.format("Orphaned block: %d", height));
+
+			repository.saveChanges();
+		} while (true);
+	}
+
 }

src/test/java/org/qora/test/minting/RewardTests.java

@@ -22,6 +22,7 @@ import org.qora.repository.RepositoryManager;
 import org.qora.test.common.AccountUtils;
 import org.qora.test.common.BlockUtils;
 import org.qora.test.common.Common;
+import org.qora.test.common.TestAccount;
 
 public class RewardTests extends Common {
 
@@ -175,4 +176,32 @@ public class RewardTests extends Common {
 		}
 	}
 
+	/** Use Alice-Chloe reward-share to bump Chloe from level 0 to level 1, then check orphaning works as expected. */
+	@Test
+	public void testLevel1() throws DataException {
+		List<Integer> cumulativeBlocksByLevel = BlockChain.getInstance().getCumulativeBlocksByLevel();
+
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			TestAccount chloe = Common.getTestAccount(repository, "chloe");
+
+			assertEquals(0, (int) chloe.getLevel());
+
+			// Alice needs to mint block containing REWARD_SHARE BEFORE Alice loses minting privs
+			byte[] aliceChloeRewardSharePrivateKey = AccountUtils.rewardShare(repository, "alice", "chloe", BigDecimal.ZERO); // Block minted by Alice
+			PrivateKeyAccount aliceChloeRewardShareAccount = new PrivateKeyAccount(repository, aliceChloeRewardSharePrivateKey);
+
+			final int minterBlocksNeeded = cumulativeBlocksByLevel.get(1);
+			// Mint enough blocks to bump testAccount level
+			for (int bc = 0; bc < minterBlocksNeeded; ++bc)
+				BlockMinter.mintTestingBlock(repository, aliceChloeRewardShareAccount);
+
+			assertEquals(1, (int) chloe.getLevel());
+
+			// Orphan back to genesis block
+			BlockUtils.orphanToBlock(repository, 1);
+
+			assertEquals(0, (int) chloe.getLevel());
+		}
+	}
+
 }

src/test/resources/test-chain-v2.json

@@ -62,7 +62,7 @@
 			{ "type": "ACCOUNT_FLAGS", "target": "QgV4s3xnzLhVBEJxcYui4u4q11yhUHsd9v", "andMask": -1, "orMask": 1, "xorMask": 0 },
 			{ "type": "REWARD_SHARE", "minterPublicKey": "2tiMr5LTpaWCgbRvkPK8TFd7k63DyHJMMFFsz9uBf1ZP", "recipient": "QgV4s3xnzLhVBEJxcYui4u4q11yhUHsd9v", "rewardSharePublicKey": "7PpfnvLSG7y4HPh8hE7KoqAjLCkv7Ui6xw4mKAkbZtox", "sharePercent": 100 },
 
-			{ "type": "ACCOUNT_LEVEL", "target": "Qci5m9k4rcwe4ruKrZZQKka4FzUUMut3er", "level": 8 }
+			{ "type": "ACCOUNT_LEVEL", "target": "Qci5m9k4rcwe4ruKrZZQKka4FzUUMut3er", "level": 5 }
 		]
 	}
 }