cmd/evm: fix nil pointer dereference in Osaka fork blob gas calculation

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.

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 @@
+[]