cmd/evm/internal/t8ntool: fix nil pointer dereference in Osaka blob gas calculation (#32714)

The parent header was missing the BaseFee field when calculating the
reserve price for EIP-7918 in the Osaka fork, causing a nil pointer
dereference. This fix ensures BaseFee is properly set from ParentBaseFee
in the environment.

Added regression test case 34 to verify Osaka fork blob gas calculation
works correctly with parent base fee.

Author: bshastry

cmd/evm/internal/t8ntool/execution.go

@@ -191,6 +191,7 @@ func (pre *Prestate) Apply(vmConfig vm.Config, chainConfig *params.ChainConfig,
 				Time:          pre.Env.ParentTimestamp,
 				ExcessBlobGas: pre.Env.ParentExcessBlobGas,
 				BlobGasUsed:   pre.Env.ParentBlobGasUsed,
+				BaseFee:       pre.Env.ParentBaseFee,
 			}
 			header := &types.Header{
 				Time:          pre.Env.Timestamp,

cmd/evm/t8n_test.go

@@ -296,6 +296,14 @@ func TestT8n(t *testing.T) {
 			output: t8nOutput{alloc: true, result: true},
 			expOut: "exp.json",
 		},
+		{ // Osaka test, EIP-7918 blob gas with parent base fee
+			base: "./testdata/34",
+			input: t8nInput{
+				"alloc.json", "txs.json", "env.json", "Osaka", "",
+			},
+			output: t8nOutput{alloc: true, result: true},
+			expOut: "exp.json",
+		},
 	} {
 		args := []string{"t8n"}
 		args = append(args, tc.output.get()...)

cmd/evm/testdata/34/README.md

@@ -0,0 +1,6 @@
+This test verifies that Osaka fork blob gas calculation works correctly when
+parentBaseFee is provided. It tests the EIP-7918 reserve price calculation
+which requires parent.BaseFee to be properly set.
+
+Regression test for: nil pointer dereference when parent.BaseFee was not
+included in the parent header during Osaka fork blob gas calculations.

cmd/evm/testdata/34/alloc.json

@@ -0,0 +1,6 @@
+{
+  "0xa94f5374fce5edbc8e2a8697c15331677e6ebf0b": {
+    "balance": "0x1000000000000000000",
+    "nonce": "0x0"
+  }
+}

cmd/evm/testdata/34/env.json

@@ -0,0 +1,18 @@
+{
+  "currentCoinbase": "0x0000000000000000000000000000000000000000",
+  "currentDifficulty": "0x0",
+  "currentRandom": "0x0000000000000000000000000000000000000000000000000000000000000000",
+  "currentGasLimit": "0x5f5e100",
+  "currentNumber": "0x1",
+  "currentTimestamp": "0x1000",
+  "parentTimestamp": "0x0",
+  "currentBaseFee": "0x10",
+  "parentBaseFee": "0x0a",
+  "parentGasUsed": "0x0",
+  "parentGasLimit": "0x5f5e100",
+  "currentExcessBlobGas": "0x0",
+  "parentExcessBlobGas": "0x0",
+  "parentBlobGasUsed": "0x20000",
+  "parentBeaconBlockRoot": "0x0000000000000000000000000000000000000000000000000000000000000000",
+  "withdrawals": []
+}

cmd/evm/testdata/34/exp.json

@@ -0,0 +1,23 @@
+{
+  "alloc": {
+    "0xa94f5374fce5edbc8e2a8697c15331677e6ebf0b": {
+      "balance": "0x1000000000000000000"
+    }
+  },
+  "result": {
+    "stateRoot": "0x01c28492482a1a1f66224726ef1059a7036fce69d1d2c991b65cd013725d5742",
+    "txRoot": "0x56e81f171bcc55a6ff8345e692c0f86e5b48e01b996cadc001622fb5e363b421",
+    "receiptsRoot": "0x56e81f171bcc55a6ff8345e692c0f86e5b48e01b996cadc001622fb5e363b421",
+    "logsHash": "0x1dcc4de8dec75d7aab85b567b6ccd41ad312451b948a7413f0a142fd40d49347",
+    "logsBloom": "0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000",
+    "currentDifficulty": null,
+    "receipts": [],
+    "gasUsed": "0x0",
+    "currentBaseFee": "0x10",
+    "withdrawalsRoot": "0x56e81f171bcc55a6ff8345e692c0f86e5b48e01b996cadc001622fb5e363b421",
+    "currentExcessBlobGas": "0x0",
+    "blobGasUsed": "0x0",
+    "requestsHash": "0xe3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855",
+    "requests": []
+  }
+}

cmd/evm/testdata/34/txs.json

@@ -0,0 +1 @@
+[]