ethclient: include block hash from FilterQuery (#17996)

ethereum/go-ethereum#16734 introduced BlockHash to the FilterQuery
struct. However, ethclient was not updated to include BlockHash in the actual
RPC request.

ethclient/ethclient.go

@@ -365,26 +365,42 @@ func (ec *Client) NonceAt(ctx context.Context, account common.Address, blockNumb
 // FilterLogs executes a filter query.
 func (ec *Client) FilterLogs(ctx context.Context, q ethereum.FilterQuery) ([]types.Log, error) {
 	var result []types.Log
-	err := ec.c.CallContext(ctx, &result, "eth_getLogs", toFilterArg(q))
+	arg, err := toFilterArg(q)
+	if err != nil {
+		return nil, err
+	}
+	err = ec.c.CallContext(ctx, &result, "eth_getLogs", arg)
 	return result, err
 }
 
 // SubscribeFilterLogs subscribes to the results of a streaming filter query.
 func (ec *Client) SubscribeFilterLogs(ctx context.Context, q ethereum.FilterQuery, ch chan<- types.Log) (ethereum.Subscription, error) {
-	return ec.c.EthSubscribe(ctx, ch, "logs", toFilterArg(q))
+	arg, err := toFilterArg(q)
+	if err != nil {
+		return nil, err
+	}
+	return ec.c.EthSubscribe(ctx, ch, "logs", arg)
 }
 
-func toFilterArg(q ethereum.FilterQuery) interface{} {
+func toFilterArg(q ethereum.FilterQuery) (interface{}, error) {
 	arg := map[string]interface{}{
-		"fromBlock": toBlockNumArg(q.FromBlock),
-		"toBlock":   toBlockNumArg(q.ToBlock),
-		"address":   q.Addresses,
-		"topics":    q.Topics,
+		"address": q.Addresses,
+		"topics":  q.Topics,
 	}
-	if q.FromBlock == nil {
-		arg["fromBlock"] = "0x0"
+	if q.BlockHash != nil {
+		arg["blockHash"] = *q.BlockHash
+		if q.FromBlock != nil || q.ToBlock != nil {
+			return nil, fmt.Errorf("cannot specify both BlockHash and FromBlock/ToBlock")
+		}
+	} else {
+		if q.FromBlock == nil {
+			arg["fromBlock"] = "0x0"
+		} else {
+			arg["fromBlock"] = toBlockNumArg(q.FromBlock)
+		}
+		arg["toBlock"] = toBlockNumArg(q.ToBlock)
 	}
-	return arg
+	return arg, nil
 }
 
 // Pending State