fix: handle system-tx in reward beneficiary

src/handler.rs

@@ -217,13 +217,17 @@ where
         let beneficiary = block.beneficiary();
 
         // calculate the L1 cost of the transaction.
-        let l1_block_info = ctx.chain().clone();
-        let Some(rlp_bytes) = &ctx.tx().rlp_bytes() else {
-            return Err(ERROR::from_string(
-                "[SCROLL] Failed to load transaction rlp_bytes.".to_string(),
-            ));
+        let l1_cost = if !ctx.tx().is_system_tx() {
+            let l1_block_info = ctx.chain().clone();
+            let Some(rlp_bytes) = &ctx.tx().rlp_bytes() else {
+                return Err(ERROR::from_string(
+                    "[SCROLL] Failed to load transaction rlp_bytes.".to_string(),
+                ));
+            };
+            l1_block_info.calculate_tx_l1_cost(rlp_bytes, ctx.cfg().spec())
+        } else {
+            U256::from(0)
         };
-        let l1_cost = l1_block_info.calculate_tx_l1_cost(rlp_bytes, ctx.cfg().spec());
 
         // reward the beneficiary with the gas fee including the L1 cost of the transaction and mark
         // the account as touched.

src/tests/fees.rs

@@ -1,17 +1,17 @@
 use crate::{
     builder::ScrollBuilder,
     handler::ScrollHandler,
-    test_utils::{context_with_funds, CALLER},
+    test_utils::{context, context_with_funds, BENEFICIARY, CALLER},
     transaction::SYSTEM_ADDRESS,
     ScrollSpecId,
 };
-use std::boxed::Box;
-
 use revm::{
     context::{result::EVMError, ContextTr, JournalTr},
-    handler::{EthFrame, EvmTr, Handler},
+    handler::{EthFrame, EvmTr, FrameResult, Handler},
+    interpreter::{CallOutcome, Gas, InstructionResult, InterpreterResult},
 };
 use revm_primitives::U256;
+use std::boxed::Box;
 
 #[test]
 fn test_should_deduct_correct_fees_bernoulli() -> Result<(), Box<dyn core::error::Error>> {
@@ -68,3 +68,26 @@ fn test_no_rollup_fee_for_system_tx() -> Result<(), Box<dyn core::error::Error>>
 
     Ok(())
 }
+
+#[test]
+fn test_reward_beneficiary_system_tx() -> Result<(), Box<dyn core::error::Error>> {
+    let ctx = context()
+        .modify_cfg_chained(|cfg| cfg.spec = ScrollSpecId::CURIE)
+        .modify_tx_chained(|tx| tx.base.caller = SYSTEM_ADDRESS);
+
+    let mut evm = ctx.build_scroll();
+    let handler = ScrollHandler::<_, EVMError<_>, EthFrame<_, _, _>>::new();
+    let gas = Gas::new_spent(21000);
+    let mut result = FrameResult::Call(CallOutcome::new(
+        InterpreterResult { result: InstructionResult::Return, output: Default::default(), gas },
+        0..0,
+    ));
+    handler.load_accounts(&mut evm)?;
+    handler.reward_beneficiary(&mut evm, &mut result)?;
+
+    // beneficiary receives gas (if any), but not rollup fee
+    let beneficiary = evm.ctx().journal().load_account(BENEFICIARY)?;
+    assert_eq!(beneficiary.info.balance, U256::from(21000));
+
+    Ok(())
+}