miner: minor feehistory fixes (ethereum#23178)

miner/worker.go

@@ -128,7 +128,7 @@ type worker struct {
 	coinbase common.Address
 	extra    []byte
 
-	snapshotMu       sync.RWMutex // The lock used to protect the block snapshot and state snapshot
+	snapshotMu       sync.RWMutex // The lock used to protect the snapshots below
 	snapshotBlock    *types.Block
 	snapshotReceipts types.Receipts
 	snapshotState    *state.StateDB
@@ -475,6 +475,16 @@ func (self *worker) push(work *Work) {
 	}
 }
 
+// copyReceipts makes a deep copy of the given receipts.
+func copyReceipts(receipts []*types.Receipt) []*types.Receipt {
+	result := make([]*types.Receipt, len(receipts))
+	for i, l := range receipts {
+		cpy := *l
+		result[i] = &cpy
+	}
+	return result
+}
+
 // makeCurrent creates a new environment for the current cycle.
 func (self *worker) makeCurrent(parent *types.Block, header *types.Header) error {
 	// Retrieve the parent state to execute on top and start a prefetcher for
@@ -534,7 +544,7 @@ func (w *worker) updateSnapshot() {
 		nil,
 		w.current.receipts,
 	)
-	w.snapshotReceipts = w.current.receipts
+	w.snapshotReceipts = copyReceipts(w.current.receipts)
 	w.snapshotState = w.current.state.Copy()
 }