Submitted by 0xAlix2
As known, when doing a Balancer EXACT_OUT batch swap, assets should be passed in reverse order, this is thoroughly documented here.
However, in SwapAction::getSwapToken, for Balancer swaps it always returns the last asset in the assets array, which is correct for EXACT_IN but wrong for EXACT_OUT, where it should be the first asset in the assets array.
Add the following in SwapAction::getSwapToken:
Error
amarcu (LoopFi) confirmed
