Merge pull request #939 from galacticcouncil/fix/weird_tokens

fix: erc20 edge cases error handling
galacticcouncil · Nov 1, 2024 · 5d4121c · 5d4121c
2 parents 8a26f60 + 000b69f
commit 5d4121c
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Showing 5 changed files with 375 additions and 4 deletions.
diff --git a/integration-tests/Cargo.toml b/integration-tests/Cargo.toml
@@ -140,7 +140,7 @@ serde_json = { workspace = true }
 hex = { workspace = true }
 
 [dev-dependencies]
-pretty_assertions = {  workspace = true }
+pretty_assertions = { workspace = true }
 pallet-relaychain-info = { workspace = true }
 xcm-emulator = { workspace = true }
 test-utils = { workspace = true }

diff --git a/integration-tests/src/erc20.rs b/integration-tests/src/erc20.rs
@@ -327,6 +327,24 @@ fn account_should_receive_tokens() {
 	});
 }
 
+#[test]
+fn erc20_transfer_returning_false_should_be_handled_as_error() {
+	TestNet::reset();
+	Hydra::execute_with(|| {
+		let token = deploy_contract("WeirdToken", deployer());
+
+		assert_noop!(
+			<Erc20Currency<Runtime> as MultiCurrency<AccountId>>::transfer(
+				token,
+				&AccountId::from(ALICE),
+				&AccountId::from(BOB),
+				100
+			),
+			Other("evm: erc20 transfer returned false")
+		);
+	});
+}
+
 #[test]
 fn bound_erc20_should_have_issuance() {
 	TestNet::reset();

diff --git a/runtime/hydradx/src/evm/erc20_currency.rs b/runtime/hydradx/src/evm/erc20_currency.rs
@@ -1,9 +1,9 @@
 use crate::evm::executor::{CallResult, Executor};
 use crate::evm::{EvmAccounts, EvmAddress};
 use ethabi::ethereum_types::BigEndianHash;
+use evm::ExitReason;
 use evm::ExitReason::Succeed;
 use evm::ExitSucceed::Returned;
-use evm::{ExitReason, ExitSucceed};
 use frame_support::{dispatch::DispatchResult, fail, pallet_prelude::*};
 use hydradx_traits::evm::{CallContext, InspectEvmAccounts, ERC20, EVM};
 use num_enum::{IntoPrimitive, TryFromPrimitive};
@@ -174,11 +174,25 @@ fn decode_integer(value: Vec<u8>) -> Option<U256> {
 	U256::checked_from(value.as_slice())
 }
 
+fn decode_bool(value: Vec<u8>) -> Option<bool> {
+	if value.len() != 32 {
+		return None;
+	}
+	let mut bytes = [0u8; 32];
+	U256::from(1).to_big_endian(&mut bytes);
+	Some(value == bytes)
+}
+
 fn handle_result(result: CallResult) -> DispatchResult {
 	let (exit_reason, value) = result;
 	match exit_reason {
-		ExitReason::Succeed(ExitSucceed::Returned) => Ok(()),
-		ExitReason::Succeed(ExitSucceed::Stopped) => Ok(()),
+		ExitReason::Succeed(_) => {
+			if Some(false) == decode_bool(value) {
+				Err(DispatchError::Other("evm: erc20 transfer returned false"))
+			} else {
+				Ok(())
+			}
+		}
 		_ => Err(DispatchError::Other(&*Box::leak(
 			format!("evm:0x{}", hex::encode(value)).into_boxed_str(),
 		))),