From d447551e20c42cecd47c3005b430924f6d8aff5f Mon Sep 17 00:00:00 2001
From: Diana Carvalho <diana@propellerheads.xyz>
Date: Wed, 16 Apr 2025 14:57:02 +0100
Subject: [PATCH] fix: Bring back receiver address zero check

Add small docs and rename variables

--- don't change below this line ---
ENG-4314 Took 1 hour 39 minutes
---
 foundry/src/TychoRouter.sol                        |  9 +++++++++
 .../evm/strategy_encoder/strategy_encoders.rs      | 14 ++++++++------
 2 files changed, 17 insertions(+), 6 deletions(-)

diff --git a/foundry/src/TychoRouter.sol b/foundry/src/TychoRouter.sol
index 3c28a11..f9597a1 100644
--- a/foundry/src/TychoRouter.sol
+++ b/foundry/src/TychoRouter.sol
@@ -411,6 +411,9 @@ contract TychoRouter is AccessControl, Dispatcher, Pausable, ReentrancyGuard {
         address receiver,
         bytes calldata swaps
     ) internal returns (uint256 amountOut) {
+        if (receiver == address(0)) {
+            revert TychoRouter__AddressZero();
+        }
         if (minAmountOut == 0) {
             revert TychoRouter__UndefinedMinAmountOut();
         }
@@ -462,6 +465,9 @@ contract TychoRouter is AccessControl, Dispatcher, Pausable, ReentrancyGuard {
         address receiver,
         bytes calldata swap_
     ) internal returns (uint256 amountOut) {
+        if (receiver == address(0)) {
+            revert TychoRouter__AddressZero();
+        }
         if (minAmountOut == 0) {
             revert TychoRouter__UndefinedMinAmountOut();
         }
@@ -516,6 +522,9 @@ contract TychoRouter is AccessControl, Dispatcher, Pausable, ReentrancyGuard {
         address receiver,
         bytes calldata swaps
     ) internal returns (uint256 amountOut) {
+        if (receiver == address(0)) {
+            revert TychoRouter__AddressZero();
+        }
         if (minAmountOut == 0) {
             revert TychoRouter__UndefinedMinAmountOut();
         }
diff --git a/src/encoding/evm/strategy_encoder/strategy_encoders.rs b/src/encoding/evm/strategy_encoder/strategy_encoders.rs
index be6316b..45a83d8 100644
--- a/src/encoding/evm/strategy_encoder/strategy_encoders.rs
+++ b/src/encoding/evm/strategy_encoder/strategy_encoders.rs
@@ -121,7 +121,7 @@ impl StrategyEncoder for SingleSwapStrategyEncoder {
                 ))
             })?;
 
-        let receiver =
+        let swap_receiver =
             if !unwrap { solution.receiver.clone() } else { self.router_address.clone() };
 
         let mut grouped_protocol_data: Vec<u8> = vec![];
@@ -136,7 +136,7 @@ impl StrategyEncoder for SingleSwapStrategyEncoder {
             );
 
             let encoding_context = EncodingContext {
-                receiver: receiver.clone(),
+                receiver: swap_receiver.clone(),
                 exact_out: solution.exact_out,
                 router_address: Some(self.router_address.clone()),
                 group_token_in: grouped_swap.input_token.clone(),
@@ -300,7 +300,9 @@ impl StrategyEncoder for SequentialSwapStrategyEncoder {
                     ))
                 })?;
 
-            let receiver = if i == grouped_swaps.len() - 1 && !unwrap {
+            // if it is the last swap and there isn't an unwrap at the end, we can set the receiver
+            // to the final user
+            let swap_receiver = if i == grouped_swaps.len() - 1 && !unwrap {
                 solution.receiver.clone()
             } else {
                 self.router_address.clone()
@@ -318,7 +320,7 @@ impl StrategyEncoder for SequentialSwapStrategyEncoder {
                 );
 
                 let encoding_context = EncodingContext {
-                    receiver: receiver.clone(),
+                    receiver: swap_receiver.clone(),
                     exact_out: solution.exact_out,
                     router_address: Some(self.router_address.clone()),
                     group_token_in: grouped_swap.input_token.clone(),
@@ -536,7 +538,7 @@ impl StrategyEncoder for SplitSwapStrategyEncoder {
                     ))
                 })?;
 
-            let receiver = if !unwrap && grouped_swap.output_token == solution.checked_token {
+            let swap_receiver = if !unwrap && grouped_swap.output_token == solution.checked_token {
                 solution.receiver.clone()
             } else {
                 self.router_address.clone()
@@ -554,7 +556,7 @@ impl StrategyEncoder for SplitSwapStrategyEncoder {
                 );
 
                 let encoding_context = EncodingContext {
-                    receiver: receiver.clone(),
+                    receiver: swap_receiver.clone(),
                     exact_out: solution.exact_out,
                     router_address: Some(self.router_address.clone()),
                     group_token_in: grouped_swap.input_token.clone(),