Merge the develop branch to the master branch, preparation to v5.0.2

contracts/upgradeable_contracts/BasicAMBMediator.sol

@@ -13,7 +13,6 @@ contract BasicAMBMediator is Ownable {
     bytes32 internal constant BRIDGE_CONTRACT = 0x811bbb11e8899da471f0e69a3ed55090fc90215227fc5fb1cb0d6e962ea7b74f; // keccak256(abi.encodePacked("bridgeContract"))
     bytes32 internal constant MEDIATOR_CONTRACT = 0x98aa806e31e94a687a31c65769cb99670064dd7f5a87526da075c5fb4eab9880; // keccak256(abi.encodePacked("mediatorContract"))
     bytes32 internal constant REQUEST_GAS_LIMIT = 0x2dfd6c9f781bb6bbb5369c114e949b69ebb440ef3d4dd6b2836225eb1dc3a2be; // keccak256(abi.encodePacked("requestGasLimit"))
-    bytes32 internal constant NONCE = 0x7ab1577440dd7bedf920cb6de2f9fc6bf7ba98c78c85a3fa1f8311aac95e1759; // keccak256(abi.encodePacked("nonce"))
 
     /**
     * @dev Sets the AMB bridge contract address. Only the owner can call this method.

contracts/upgradeable_contracts/TokenBridgeMediator.sol

@@ -86,8 +86,6 @@ contract TokenBridgeMediator is BasicAMBMediator, BasicTokenBridge {
     /**
     * @dev Handles the bridged tokens. Checks that the value is inside the execution limits and invokes the method
     * to execute the Mint or Unlock accordingly.
-    * nonce parameter is a unique message identifier on AMB bridge, it is not actually used by this method,
-    * it serves as unique reference.
     * @param _recipient address that will receive the tokens
     * @param _value amount of tokens to be received
     */

contracts/upgradeable_contracts/amb_native_to_erc20/BasicAMBNativeToErc20.sol

@@ -75,7 +75,7 @@ contract BasicAMBNativeToErc20 is
     * @return patch value of the version
     */
     function getBridgeInterfacesVersion() external pure returns (uint64 major, uint64 minor, uint64 patch) {
-        return (1, 0, 0);
+        return (1, 0, 1);
     }
 
     /**

contracts/upgradeable_contracts/amb_native_to_erc20/HomeAMBNativeToErc20.sol

@@ -107,6 +107,7 @@ contract HomeAMBNativeToErc20 is BasicAMBNativeToErc20 {
     * @param _value amount of native tokens to be received
     */
     function executeActionOnFixedTokens(address _receiver, uint256 _value) internal {
+        setMediatorBalance(mediatorBalance().sub(_value));
         Address.safeSendValue(_receiver, _value);
     }
 
@@ -156,7 +157,7 @@ contract HomeAMBNativeToErc20 is BasicAMBNativeToErc20 {
         require(balance > mediatorBalance());
         uint256 diff = balance.sub(mediatorBalance());
         setTotalSpentPerDay(getCurrentDay(), totalSpentPerDay(getCurrentDay()).add(diff));
-        setMediatorBalance(mediatorBalance().add(diff));
+        setMediatorBalance(balance);
         passMessage(_receiver, _receiver, diff);
     }
 }

contracts/upgradeable_contracts/arbitrary_message/BasicAMB.sol

@@ -62,6 +62,22 @@ contract BasicAMB is BasicBridge, VersionableAMB {
         uintStorage[MAX_GAS_PER_TX] = _maxGasPerTx;
     }
 
+    /**
+     * Internal function for retrieving chain id for the source network
+     * @return chain id for the current network
+     */
+    function sourceChainId() public view returns (uint256) {
+        return uintStorage[SOURCE_CHAIN_ID];
+    }
+
+    /**
+     * Internal function for retrieving chain id for the destination network
+     * @return chain id for the destination network
+     */
+    function destinationChainId() public view returns (uint256) {
+        return uintStorage[DESTINATION_CHAIN_ID];
+    }
+
     /**
      * Updates chain ids of used networks
      * @param _sourceChainId chain id for current network
@@ -115,14 +131,6 @@ contract BasicAMB is BasicBridge, VersionableAMB {
         uintStorage[DESTINATION_CHAIN_ID_LENGTH] = destinationChainIdLength;
     }
 
-    /**
-     * Internal function for retrieving chain id for the source network
-     * @return chain id for the current network
-     */
-    function _sourceChainId() internal view returns (uint256) {
-        return uintStorage[SOURCE_CHAIN_ID];
-    }
-
     /**
      * Internal function for retrieving chain id length for the source network
      * @return chain id for the current network
@@ -131,14 +139,6 @@ contract BasicAMB is BasicBridge, VersionableAMB {
         return uintStorage[SOURCE_CHAIN_ID_LENGTH];
     }
 
-    /**
-     * Internal function for retrieving chain id for the destination network
-     * @return chain id for the destination network
-     */
-    function _destinationChainId() internal view returns (uint256) {
-        return uintStorage[DESTINATION_CHAIN_ID];
-    }
-
     /**
      * Internal function for retrieving chain id length for the destination network
      * @return chain id for the destination network
@@ -161,6 +161,6 @@ contract BasicAMB is BasicBridge, VersionableAMB {
      * @param _chainId destination chain id of the received message
      */
     function _isDestinationChainIdValid(uint256 _chainId) internal returns (bool res) {
-        return _chainId == _sourceChainId();
+        return _chainId == sourceChainId();
     }
 }

contracts/upgradeable_contracts/arbitrary_message/MessageDelivery.sol

@@ -52,30 +52,30 @@ contract MessageDelivery is BasicAMB, MessageProcessor {
     * @param _gas gas limit used on the other network for executing a message
     */
     function _packHeader(address _contract, uint256 _gas) internal view returns (bytes memory header) {
-        uint256 sourceChainId = _sourceChainId();
-        uint256 sourceChainIdLength = _sourceChainIdLength();
-        uint256 destinationChainId = _destinationChainId();
-        uint256 destinationChainIdLength = _destinationChainIdLength();
+        uint256 srcChainId = sourceChainId();
+        uint256 srcChainIdLength = _sourceChainIdLength();
+        uint256 dstChainId = destinationChainId();
+        uint256 dstChainIdLength = _destinationChainIdLength();
 
         bytes32 mVer = MESSAGE_PACKING_VERSION;
         uint256 nonce = _nonce();
 
         // Bridge id is recalculated every time again and again, since it is still cheaper than using SLOAD opcode (800 gas)
-        bytes32 bridgeId = keccak256(abi.encodePacked(sourceChainId, address(this))) &
+        bytes32 bridgeId = keccak256(abi.encodePacked(srcChainId, address(this))) &
             0x00000000ffffffffffffffffffffffffffffffffffffffff0000000000000000;
         // 79 = 4 + 20 + 8 + 20 + 20 + 4 + 1 + 1 + 1
-        header = new bytes(79 + sourceChainIdLength + destinationChainIdLength);
+        header = new bytes(79 + srcChainIdLength + dstChainIdLength);
 
         // In order to save the gas, the header is packed in the reverse order.
         // With such approach, it is possible to store right-aligned values without any additional bit shifts.
         assembly {
             let ptr := add(header, mload(header)) // points to the last word of header
-            mstore(ptr, destinationChainId)
-            mstore(sub(ptr, destinationChainIdLength), sourceChainId)
+            mstore(ptr, dstChainId)
+            mstore(sub(ptr, dstChainIdLength), srcChainId)
 
             mstore(add(header, 79), 0x00)
-            mstore(add(header, 78), destinationChainIdLength)
-            mstore(add(header, 77), sourceChainIdLength)
+            mstore(add(header, 78), dstChainIdLength)
+            mstore(add(header, 77), srcChainIdLength)
             mstore(add(header, 76), _gas)
             mstore(add(header, 72), _contract)
             mstore(add(header, 52), caller)

contracts/upgradeable_contracts/arbitrary_message/VersionableAMB.sol

@@ -17,6 +17,6 @@ contract VersionableAMB is VersionableBridge {
      * @return (major, minor, patch) version triple
      */
     function getBridgeInterfacesVersion() external pure returns (uint64 major, uint64 minor, uint64 patch) {
-        return (5, 0, 1);
+        return (5, 0, 2);
     }
 }