rpcdaemon: fix eth_call without sender

silkworm/rpc/commands/eth_api_test.cpp

@@ -96,7 +96,7 @@ TEST_CASE_METHOD(test::RpcApiE2ETest, "fuzzy: eth_call invalid params", "[rpc][a
     CHECK(nlohmann::json::parse(reply) == R"({
         "jsonrpc":"2.0",
         "id":1,
-        "error":{"code":-32000,"message":"malformed transaction: cannot recover sender"}
+        "result":"0x"
     })"_json);
 }
 

silkworm/rpc/core/evm_executor.cpp

@@ -238,9 +238,6 @@ ExecutionResult EVMExecutor::call(
         evm.add_tracer(*tracer);
     }
 
-    if (!txn.sender()) {
-        return {std::nullopt, txn.gas_limit, Bytes{}, "malformed transaction: cannot recover sender"};
-    }
     ibs_state_.access_account(*txn.sender());
 
     const evmc_revision rev{evm.revision()};

silkworm/rpc/types/call.hpp

@@ -51,6 +51,9 @@ struct Call {
         silkworm::Transaction txn{};
         if (from) {
             txn.set_sender(*from);
+        } else {
+            constexpr auto zero_address = 0x0000000000000000000000000000000000000000_address;
+            txn.set_sender(zero_address);
         }
         txn.to = to;
         if (override_nonce) {