Small query fix for BatchRouter (#1089)

balancer · Nov 4, 2024 · c8b7fa8 · c8b7fa8
1 parent 65fbede
commit c8b7fa8
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Showing 3 changed files with 30 additions and 3 deletions.
diff --git a/pkg/vault/contracts/BatchRouter.sol b/pkg/vault/contracts/BatchRouter.sol
@@ -225,8 +225,8 @@ contract BatchRouter is IBatchRouter, BatchRouterCommon, ReentrancyGuardTransien
                     // required amount when performing the operation. These tokens might be the output of a previous
                     // step, in which case the user will have a BPT credit.
 
-                    if (stepLocals.isFirstStep && params.sender != address(this)) {
-                        if (stepExactAmountIn > 0) {
+                    if (stepLocals.isFirstStep) {
+                        if (stepExactAmountIn > 0 && params.sender != address(this)) {
                             // If this is the first step, the sender must have the tokens. Therefore, we can transfer
                             // them to the Router, which acts as an intermediary. If the sender is the Router, we just
                             // skip this step (useful for queries).

diff --git a/pkg/vault/contracts/CompositeLiquidityRouter.sol b/pkg/vault/contracts/CompositeLiquidityRouter.sol
@@ -1,6 +1,6 @@
 // SPDX-License-Identifier: GPL-3.0-or-later
 
-pragma solidity ^0.8.26;
+pragma solidity ^0.8.24;
 
 import { IERC20 } from "@openzeppelin/contracts/token/ERC20/IERC20.sol";
 import { IPermit2 } from "permit2/src/interfaces/IPermit2.sol";

diff --git a/pkg/vault/test/foundry/BatchRouter.t.sol b/pkg/vault/test/foundry/BatchRouter.t.sol
@@ -4,6 +4,8 @@ pragma solidity ^0.8.24;
 
 import "forge-std/Test.sol";
 
+import { IERC20 } from "@openzeppelin/contracts/token/ERC20/IERC20.sol";
+
 import { IBatchRouter } from "@balancer-labs/v3-interfaces/contracts/vault/IBatchRouter.sol";
 
 import { MOCK_BATCH_ROUTER_VERSION } from "../../contracts/test/BatchRouterMock.sol";
@@ -32,4 +34,29 @@ contract BatchRouterTest is BaseVaultTest {
     function testBatchRouterVersion() public view {
         assertEq(batchRouter.version(), MOCK_BATCH_ROUTER_VERSION, "BatchRouter version mismatch");
     }
+
+    function testQuerySingleStepRemove() public {
+        // create a swap step and query the batch router, where the first token is the bpt.
+        IBatchRouter.SwapPathStep[] memory step = new IBatchRouter.SwapPathStep[](1);
+        step[0] = IBatchRouter.SwapPathStep(address(pool), IERC20(address(dai)), false);
+
+        uint256 totalSupply = IERC20(pool).totalSupply();
+        console.log("total BPT supply", totalSupply);
+        uint256 bptAmountIn = 1e18;
+
+        require(bptAmountIn < totalSupply);
+
+        IBatchRouter.SwapPathExactAmountIn memory path = IBatchRouter.SwapPathExactAmountIn(
+            IERC20(address(pool)),
+            step,
+            bptAmountIn,
+            0
+        );
+
+        IBatchRouter.SwapPathExactAmountIn[] memory paths = new IBatchRouter.SwapPathExactAmountIn[](1);
+        paths[0] = path;
+
+        vm.prank(alice, address(0));
+        batchRouter.querySwapExactIn(paths, address(0), bytes(""));
+    }
 }