Improve of 10_Wallet.sol

solidity/10_Wallet.sol

@@ -5,41 +5,47 @@ pragma AbiHeader expire;
 /// @author Tonlabs
 contract Wallet {
     /*
-     Exception codes:
-      100 - message sender is not a wallet owner.
-      101 - invalid transfer value.
+     * Exception codes:
+     * - 100: the message creator (tx signer, `msg.pubkey`) is not the wallet owner (`tvm.pubkey`)
+     * - 101: the wallet owner (stored in `tvm.pubkey`, part of state init) is not set up properly
      */
 
-    /// @dev Contract constructor.
+    /// @dev Contract constructor
     constructor() {
-        // check that contract's public key is set
+        // Check the contract owner (`tvm.pubkey`) is set up properly (is not zero)
         require(tvm.pubkey() != 0, 101);
-        // Check that message has signature (msg.pubkey() is not zero) and message is signed with the owner's private key
-        require(msg.pubkey() == tvm.pubkey(), 102);
+
+        // Check the message has a signature (`msg.pubkey` is not zero) and the message sender
+        //   (tx signer, `msg.pubkey`) is the contract owner (`tvm.pubkey`)
+        require(msg.pubkey() == tvm.pubkey(), 100);
+
+        // Needed for initialization to be possible by an external inbound message
         tvm.accept();
     }
 
-
-    // Modifier that allows function to accept external call only if it was signed
-    // with contract owner's public key.
+    /// @dev Modifier that allows a function to accept an external inbound call only
+    ///   if it was signed with the contract owner's public key
     modifier checkOwnerAndAccept {
-        // Check that inbound message was signed with owner's public key.
-        // Runtime function that obtains sender's public key.
+        // Check that the inbound message was signed with the owner's public key
         require(msg.pubkey() == tvm.pubkey(), 100);
 
-		// Runtime function that allows contract to process inbound messages spending
-		// its own resources (it's necessary if contract should process all inbound messages,
-		// not only those that carry value with them).
+		// Runtime function that allows the contract to process external messages spending
+		// its own resources (it's necessary if the contract should process external messages,
+		// not only those that carry value with them)
 		tvm.accept();
+
+        // Function body execution
 		_;
 	}
 
-    /// @dev Allows to transfer tons to the destination account.
-    /// @param dest Transfer target address.
-    /// @param value Nanoevers value to transfer.
-    /// @param bounce Flag that enables bounce message in case of target contract error.
+    /// @dev Allows transferring tons to the destination account
+    /// @param dest Transfer target address
+    /// @param value Nanoevers value to transfer
+    /// @param bounce Flag that enables a bounce message in case of the target contract error
     function sendTransaction(address dest, uint128 value, bool bounce) public view checkOwnerAndAccept {
-         // Runtime function that allows to make a transfer with arbitrary settings.
-        dest.transfer(value, bounce, 0);
+        // Runtime function that allows making a transfer with arbitrary settings
+        // Flag is hardcoded to `2` in order to avoid
+        //   [Tx Replay Attack](https://everscale.guide/smart_contracts/replay_protection)
+        dest.transfer(value, bounce, 2);
     }
 }