ethclient: serialize negative block number as "pending" (#21177)

Fixes #21175

Co-authored-by: sammy007 <[email protected]>
Co-authored-by: Adam Schmideg <[email protected]>

Author: sammy007

core/types/gen_log_json.go

@@ -44,11 +44,11 @@ type Log struct {
 	// hash of the transaction
 	TxHash common.Hash `json:"transactionHash" gencodec:"required"`
 	// index of the transaction in the block
-	TxIndex uint `json:"transactionIndex" gencodec:"required"`
+	TxIndex uint `json:"transactionIndex"`
 	// hash of the block in which the transaction was included
 	BlockHash common.Hash `json:"blockHash"`
 	// index of the log in the block
-	Index uint `json:"logIndex" gencodec:"required"`
+	Index uint `json:"logIndex"`
 
 	// The Removed field is true if this log was reverted due to a chain reorganisation.
 	// You must pay attention to this field if you receive logs through a filter query.

core/types/log.go

@@ -282,6 +282,10 @@ func toBlockNumArg(number *big.Int) string {
 	if number == nil {
 		return "latest"
 	}
+	pending := big.NewInt(-1)
+	if number.Cmp(pending) == 0 {
+		return "pending"
+	}
 	return hexutil.EncodeBig(number)
 }
 

ethclient/ethclient.go

@@ -97,6 +97,22 @@ func TestToFilterArg(t *testing.T) {
 			},
 			nil,
 		},
+		{
+			"with negative fromBlock and negative toBlock",
+			ethereum.FilterQuery{
+				Addresses: addresses,
+				FromBlock: big.NewInt(-1),
+				ToBlock:   big.NewInt(-1),
+				Topics:    [][]common.Hash{},
+			},
+			map[string]interface{}{
+				"address":   addresses,
+				"fromBlock": "pending",
+				"toBlock":   "pending",
+				"topics":    [][]common.Hash{},
+			},
+			nil,
+		},
 		{
 			"with blockhash",
 			ethereum.FilterQuery{