check readonly on batch append

core/rawdb/freezer_batch.go

@@ -115,6 +115,11 @@ func (batch *freezerTableBatch) reset() {
 // precautionary parameter to ensure data correctness, but the table will reject already
 // existing data.
 func (batch *freezerTableBatch) Append(item uint64, data interface{}) error {
+	// Sanity check. In principle this method shouldn't be called at all
+	// in readonly mode.
+	if batch.t.readonly {
+		return fmt.Errorf("permission error: table in readonly mode")
+	}
 	if item != batch.curItem {
 		return fmt.Errorf("%w: have %d want %d", errOutOrderInsertion, item, batch.curItem)
 	}
@@ -135,6 +140,11 @@ func (batch *freezerTableBatch) Append(item uint64, data interface{}) error {
 // precautionary parameter to ensure data correctness, but the table will reject already
 // existing data.
 func (batch *freezerTableBatch) AppendRaw(item uint64, blob []byte) error {
+	// Sanity check. In principle this method shouldn't be called at all
+	// in readonly mode.
+	if batch.t.readonly {
+		return fmt.Errorf("permission error: table in readonly mode")
+	}
 	if item != batch.curItem {
 		return fmt.Errorf("%w: have %d want %d", errOutOrderInsertion, item, batch.curItem)
 	}

core/rawdb/freezer_table_test.go

@@ -903,13 +903,12 @@ func TestFreezerReadonlyBasics(t *testing.T) {
 	if !bytes.Equal(v, exp) {
 		t.Errorf("retrieved value is incorrect")
 	}
-	// Now write some data. This should fail either during AppendRaw or Commit
+	// Now write some data. Append/AppendRaw should fail.
 	batch := f.newBatch()
-	writeErr := batch.AppendRaw(32, make([]byte, 1))
-	if writeErr == nil {
-		writeErr = batch.commit()
+	if err := batch.AppendRaw(32, make([]byte, 1)); err == nil {
+		t.Errorf("Writing to readonly table should fail")
 	}
-	if writeErr == nil {
-		t.Fatalf("Writing to readonly table should fail")
+	if err := batch.Append(0, make([]byte, 1)); err == nil {
+		t.Errorf("Writing to readonly table should fail")
 	}
 }