Merge #38: whitelist: Fix occasional overflow in unit test

02f1666 whitelist: Fix occasional overflow in unit test (Steven Roose)

Pull request description:

ACKs for top commit:
  jonasnick:
    utACK 02f1666

Tree-SHA512: 2eef146993378914658981f595680ae1d0616b60844dae306f53dd44cdde7042166008bd5d512dfb91583d574663bc5a78ad14048e1fcd55cc9095ae7e8cc296

Author: jonasnick

src/zkp/whitelist.rs

@@ -404,7 +404,7 @@ mod tests {
             // incorrectly serialized with byte changed
             let mut encoded = correct_signature.serialize();
             let len = encoded.len();
-            encoded[len - 1] = (encoded[len - 1] + 1) % 255;
+            encoded[len - 1] = encoded[len - 1] ^ 0x01;
             let decoded = WhitelistSignature::from_slice(&encoded).unwrap();
             assert_eq!(
                 Err(Error::InvalidWhitelistProof),