Fix forging bit mask for account flags

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

@@ -2,13 +2,14 @@ package org.qora.account;
 
 import org.qora.block.BlockChain;
 import org.qora.repository.DataException;
+import org.qora.utils.BitTwiddling;
 
 /** Relating to whether accounts can forge. */
 public class Forging {
 
 	/** Returns mask for account flags for forging bits. */
 	public static int getForgingMask() {
-		return (1 << BlockChain.getInstance().getForgingTiers().size()) - 1;
+		return BitTwiddling.calcMask(BlockChain.getInstance().getForgingTiers().size() - 1);
 	}
 
 	public static boolean canForge(Account account) throws DataException {

src/main/java/org/qora/utils/BitTwiddling.java

@@ -0,0 +1,24 @@
+package org.qora.utils;
+
+public class BitTwiddling {
+
+	/**
+	 * Returns bit-mask for values up to, and including, <tt>maxValue</tt>.
+	 * <p>
+	 * e.g. for values up to 5 (0101b) this returns a mask of 7 (0111b).
+	 * <p>
+	 * Based on Integer.highestOneBit.
+	 * 
+	 * @param maxValue
+	 * @return mask
+	 */
+	public static int calcMask(int maxValue) {
+		maxValue |= maxValue >> 1;
+		maxValue |= maxValue >> 2;
+		maxValue |= maxValue >> 4;
+		maxValue |= maxValue >> 8;
+		maxValue |= maxValue >> 16;
+		return maxValue;
+	}
+
+}