From db8f7da2013e0c7a2d9de0d9a7ea6b034c00e028 Mon Sep 17 00:00:00 2001
From: Sally MacFarlane <macfarla.github@gmail.com>
Date: Wed, 11 Jun 2025 11:18:06 +0200
Subject: [PATCH] return min gas cost if inputs are zero

Signed-off-by: Sally MacFarlane <macfarla.github@gmail.com>
---
 .../hyperledger/besu/evm/gascalculator/OsakaGasCalculator.java | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/evm/src/main/java/org/hyperledger/besu/evm/gascalculator/OsakaGasCalculator.java b/evm/src/main/java/org/hyperledger/besu/evm/gascalculator/OsakaGasCalculator.java
index adc9f445fcd..21f8a30f880 100644
--- a/evm/src/main/java/org/hyperledger/besu/evm/gascalculator/OsakaGasCalculator.java
+++ b/evm/src/main/java/org/hyperledger/besu/evm/gascalculator/OsakaGasCalculator.java
@@ -60,6 +60,9 @@ public long modExpGasCost(final Bytes input) {
         clampedAdd(BigIntegerModularExponentiationPrecompiledContract.BASE_OFFSET, baseLength);
 
     final long maxLength = Math.max(modulusLength, baseLength);
+    if (maxLength <= 0) {
+      return 500L;
+    }
     long multiplicationComplexity = 16;
     long words = (maxLength + 7L) / 8L;
     words = Words.clampedMultiply(words, words);