remove blocking fallback pre-initialization

Author: amiecorso

src/EIP7702Proxy.sol

@@ -24,12 +24,6 @@ contract EIP7702Proxy is Proxy {
     /// @notice Function selector on the implementation that is guarded from direct calls
     bytes4 immutable guardedInitializer;
 
-    /// @dev Storage slot with the initialized flag, calculated via ERC-7201
-    bytes32 internal constant INITIALIZED_SLOT =
-        keccak256(
-            abi.encode(uint256(keccak256("EIP7702Proxy.initialized")) - 1)
-        ) & ~bytes32(uint256(0xff));
-
     /// @notice Emitted when the initialization signature is invalid
     error InvalidSignature();
 
@@ -55,11 +49,6 @@ contract EIP7702Proxy is Proxy {
         guardedInitializer = initializer;
     }
 
-    /// @dev Checks if proxy has been initialized by checking the initialized flag
-    function _isInitialized() internal view returns (bool) {
-        return StorageSlot.getBooleanSlot(INITIALIZED_SLOT).value;
-    }
-
     /// @notice Initializes the proxy and implementation with a signed payload
     ///
     /// @dev Signature must be from this contract's address
@@ -78,9 +67,6 @@ contract EIP7702Proxy is Proxy {
         address recovered = ECDSA.recover(hash, signature);
         if (recovered != address(this)) revert InvalidSignature();
 
-        // Set initialized flag before upgrading
-        StorageSlot.getBooleanSlot(INITIALIZED_SLOT).value = true;
-
         // Set the ERC-1967 implementation slot, emit Upgraded event, call the initializer
         ERC1967Utils.upgradeToAndCall(
             initialImplementation,
@@ -100,9 +86,6 @@ contract EIP7702Proxy is Proxy {
         bytes32 hash,
         bytes calldata signature
     ) external returns (bytes4) {
-        // Check initialization status first
-        if (!_isInitialized()) revert ProxyNotInitialized();
-
         // First try delegatecall to implementation
         (bool success, bytes memory result) = _implementation().delegatecall(
             msg.data
@@ -133,15 +116,17 @@ contract EIP7702Proxy is Proxy {
     /// @dev Handles ERC-1271 signature validation by enforcing an ecrecover check if signatures fail `isValidSignature` check
     /// @dev Guards a specified initializer function from being called directly
     function _fallback() internal override {
-        if (!_isInitialized()) revert ProxyNotInitialized();
-
         // block guarded initializer from being called
         if (msg.sig == guardedInitializer) revert InvalidInitializer();
 
         _delegate(_implementation());
     }
 
+    /// @notice Returns the implementation address, falling back to the initial implementation if the ERC-1967 implementation slot is not set
+    /// @return The implementation address
     function _implementation() internal view override returns (address) {
+        if (ERC1967Utils.getImplementation() == address(0))
+            return initialImplementation;
         return ERC1967Utils.getImplementation();
     }
 

test/EIP7702Proxy/delegate.t.sol

@@ -127,13 +127,4 @@ contract DelegateTest is EIP7702ProxyBase {
         vm.expectRevert(EIP7702Proxy.ProxyNotInitialized.selector);
         uninitProxy.call(data);
     }
-
-    function test_reverts_whenCallingBeforeInitialization() public {
-        // Deploy a fresh proxy without initializing it
-        address payable uninitProxy = payable(makeAddr("uninitProxy"));
-        _deployProxy(uninitProxy);
-
-        vm.expectRevert(EIP7702Proxy.ProxyNotInitialized.selector);
-        MockImplementation(payable(uninitProxy)).owner();
-    }
 }

test/EIP7702Proxy/isValidSignature.t.sol

@@ -114,19 +114,6 @@ contract FailingImplementationTest is IsValidSignatureTestBase {
         );
         assertEq(result, ERC1271_FAIL_VALUE, "Should reject empty signature");
     }
-
-    function test_reverts_whenCalledBeforeInitialization() public {
-        // Deploy a fresh proxy without initializing
-        address payable uninitProxy = payable(makeAddr("uninitProxy"));
-        _deployProxy(uninitProxy);
-
-        // Try to call isValidSignature
-        bytes32 hash = keccak256("test message");
-        bytes memory signature = new bytes(65);
-
-        vm.expectRevert(EIP7702Proxy.ProxyNotInitialized.selector);
-        EIP7702Proxy(uninitProxy).isValidSignature(hash, signature);
-    }
 }
 
 /**