♻️ Make fallback payable (ethereum#651)

Author: Vectorized

.gas-snapshot

@@ -221,27 +221,28 @@ ERC2981Test:testRoyaltyOverflowCheckDifferential(uint256,uint256) (runs: 256, μ
 ERC2981Test:testSetAndGetRoyaltyInfo(uint256) (runs: 256, μ: 107629, ~: 104801)
 ERC2981Test:test__codesize() (gas: 8419)
 ERC4337FactoryTest:testDeploy() (gas: 112614)
-ERC4337FactoryTest:testDeploy(uint256) (runs: 256, μ: 135780, ~: 135781)
-ERC4337FactoryTest:testDeployDeterministic(uint256) (runs: 256, μ: 132593, ~: 137159)
+ERC4337FactoryTest:testDeploy(uint256) (runs: 256, μ: 135779, ~: 135788)
+ERC4337FactoryTest:testDeployDeterministic(uint256) (runs: 256, μ: 131474, ~: 137165)
 ERC4337FactoryTest:testDeployDeterministicRevertWithDeploymentFailed() (gas: 96883638)
-ERC4337FactoryTest:test__codesize() (gas: 11343)
+ERC4337FactoryTest:test__codesize() (gas: 11330)
+ERC4337Test:testCdFallback() (gas: 1178533)
 ERC4337Test:testDelegateExecute() (gas: 370417)
-ERC4337Test:testDelegateExecute(uint256) (runs: 256, μ: 353981, ~: 343995)
+ERC4337Test:testDelegateExecute(uint256) (runs: 256, μ: 355257, ~: 343995)
 ERC4337Test:testDelegateExecuteRevertsIfOwnerSlotValueChanged() (gas: 318832)
-ERC4337Test:testDepositFunctions() (gas: 502811)
-ERC4337Test:testDirectStorage() (gas: 70943)
+ERC4337Test:testDepositFunctions() (gas: 502817)
+ERC4337Test:testDirectStorage() (gas: 70965)
 ERC4337Test:testETHReceived() (gas: 16606)
 ERC4337Test:testExecute() (gas: 382275)
 ERC4337Test:testExecuteBatch() (gas: 691377)
-ERC4337Test:testExecuteBatch(uint256) (runs: 256, μ: 532071, ~: 367759)
+ERC4337Test:testExecuteBatch(uint256) (runs: 256, μ: 505137, ~: 367584)
 ERC4337Test:testInitializer() (gas: 285354)
 ERC4337Test:testIsValidSignature() (gas: 66115)
 ERC4337Test:testIsValidSignatureWrapped() (gas: 388471)
-ERC4337Test:testOnERC1155BatchReceived() (gas: 1393612)
-ERC4337Test:testOnERC1155Received() (gas: 1390956)
-ERC4337Test:testOnERC721Received() (gas: 1311297)
-ERC4337Test:testValidateUserOp() (gas: 491252)
-ERC4337Test:test__codesize() (gas: 44398)
+ERC4337Test:testOnERC1155BatchReceived() (gas: 1393588)
+ERC4337Test:testOnERC1155Received() (gas: 1390889)
+ERC4337Test:testOnERC721Received() (gas: 1311273)
+ERC4337Test:testValidateUserOp() (gas: 491274)
+ERC4337Test:test__codesize() (gas: 46551)
 ERC4626Test:testDepositWithNoApprovalReverts() (gas: 16371)
 ERC4626Test:testDepositWithNotEnoughApprovalReverts() (gas: 89884)
 ERC4626Test:testDifferentialFullMulDiv(uint256,uint256,uint256) (runs: 256, μ: 3336, ~: 3201)
@@ -836,9 +837,9 @@ OwnableTest:testTransferOwnership() (gas: 19467)
 OwnableTest:testTransferOwnership(address,bool,bool) (runs: 256, μ: 13601, ~: 12828)
 OwnableTest:test__codesize() (gas: 12233)
 ReceiverTest:testETHReceived() (gas: 9621)
-ReceiverTest:testOnERC1155BatchReceived() (gas: 48994)
-ReceiverTest:testOnERC1155Received() (gas: 46736)
-ReceiverTest:testOnERC721Received() (gas: 64132)
+ReceiverTest:testOnERC1155BatchReceived() (gas: 48975)
+ReceiverTest:testOnERC1155Received() (gas: 46717)
+ReceiverTest:testOnERC721Received() (gas: 64108)
 ReceiverTest:test__codesize() (gas: 3309)
 RedBlackTreeLibTest:testRedBlackTreeBenchUint160() (gas: 3438446)
 RedBlackTreeLibTest:testRedBlackTreeBenchUint256() (gas: 5850739)

src/accounts/ERC4337.sol

@@ -369,7 +369,7 @@ contract ERC4337 is Ownable, UUPSUpgradeable, Receiver {
     /// @dev Handle token callbacks. If no token callback is triggered,
     /// use `LibZip.cdFallback` for generalized calldata decompression.
     /// If you don't need either, re-override this function.
-    fallback() external virtual override(Receiver) receiverFallback {
+    fallback() external payable virtual override(Receiver) receiverFallback {
         LibZip.cdFallback();
     }
 }

src/accounts/Receiver.sol

@@ -13,7 +13,7 @@ abstract contract Receiver {
     receive() external payable virtual {}
 
     /// @dev Fallback function with the `receiverFallback` modifier.
-    fallback() external virtual receiverFallback {}
+    fallback() external payable virtual receiverFallback {}
 
     /// @dev Modifier for the fallback function to handle token callbacks.
     modifier receiverFallback() virtual {

test/ERC4337.t.sol

@@ -10,6 +10,7 @@ import {MockERC1155} from "./utils/mocks/MockERC1155.sol";
 import {MockERC1271Wallet} from "./utils/mocks/MockERC1271Wallet.sol";
 import {LibClone} from "../src/utils/LibClone.sol";
 import {LibString} from "../src/utils/LibString.sol";
+import {LibZip} from "../src/utils/LibZip.sol";
 
 contract Target {
     error TargetError(bytes data);
@@ -224,6 +225,37 @@ contract ERC4337Test is SoladyTest {
         assertEq(account.getDeposit(), 123 - 12);
     }
 
+    function testCdFallback() public {
+        vm.deal(address(account), 1 ether);
+        account.initialize(address(this));
+
+        vm.etch(account.entryPoint(), address(new MockEntryPoint()).code);
+        assertEq(account.getDeposit(), 0);
+
+        bytes memory data = LibZip.cdCompress(abi.encodeWithSignature("addDeposit()"));
+        (bool success,) = address(account).call{value: 123}(data);
+        assertTrue(success);
+        assertEq(account.getDeposit(), 123);
+
+        ERC4337.Call[] memory calls = new ERC4337.Call[](2);
+        calls[0].target = address(new Target());
+        calls[1].target = address(new Target());
+        calls[0].value = 123;
+        calls[1].value = 456;
+        calls[0].data = abi.encodeWithSignature("setData(bytes)", _randomBytes(111));
+        calls[1].data = abi.encodeWithSignature("setData(bytes)", _randomBytes(222));
+
+        data = LibZip.cdCompress(
+            abi.encodeWithSignature("executeBatch((address,uint256,bytes)[])", calls)
+        );
+        (success,) = address(account).call(data);
+        assertTrue(success);
+        assertEq(Target(calls[0].target).datahash(), keccak256(_randomBytes(111)));
+        assertEq(Target(calls[1].target).datahash(), keccak256(_randomBytes(222)));
+        assertEq(calls[0].target.balance, 123);
+        assertEq(calls[1].target.balance, 456);
+    }
+
     struct _TestTemps {
         bytes32 userOpHash;
         address signer;