From bf6da20012f63573fff4dad19634c5bf5dbef964 Mon Sep 17 00:00:00 2001
From: Morty <70688412+yiweichi@users.noreply.github.com>
Date: Sat, 19 Apr 2025 22:02:31 +0800
Subject: [PATCH] eth/gasprice: fix eth_feeHistory blobGasUsedRatio divide zero
 (#31663)

The API `eth_feeHistory` returns
`{"jsonrpc":"2.0","id":1,"error":{"code":-32603,"message":"json:
unsupported value: NaN"}}`, when we query `eth_feeHistory` with a old
block that without a blob, or when the field
`config.blobSchedule.cancun.max` in genesis.config is 0 (that happens
for some projects fork geth but they don't have blob).

So here we specially handle the case when maxBlobGas == 0 to prevent
this issue from happening.
---
 eth/gasprice/feehistory.go | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/eth/gasprice/feehistory.go b/eth/gasprice/feehistory.go
index 59830e9fe8..e5a197f640 100644
--- a/eth/gasprice/feehistory.go
+++ b/eth/gasprice/feehistory.go
@@ -108,7 +108,9 @@ func (oracle *Oracle) processBlock(bf *blockFees, percentiles []float64) {
 	bf.results.gasUsedRatio = float64(bf.header.GasUsed) / float64(bf.header.GasLimit)
 	if blobGasUsed := bf.header.BlobGasUsed; blobGasUsed != nil {
 		maxBlobGas := eip4844.MaxBlobGasPerBlock(config, bf.header.Time)
-		bf.results.blobGasUsedRatio = float64(*blobGasUsed) / float64(maxBlobGas)
+		if maxBlobGas != 0 {
+			bf.results.blobGasUsedRatio = float64(*blobGasUsed) / float64(maxBlobGas)
+		}
 	}
 
 	if len(percentiles) == 0 {