check for infinity before calling out to jni for ecmul

Signed-off-by: garyschulte <garyschulte@gmail.com>

Author: garyschulte

evm/src/main/java/org/hyperledger/besu/evm/precompile/AltBN128MulPrecompiledContract.java

@@ -38,6 +38,7 @@ public class AltBN128MulPrecompiledContract extends AbstractAltBnPrecompiledCont
       new BigInteger(
           "115792089237316195423570985008687907853269984665640564039457584007913129639935");
 
+  private static final Bytes POINT_AT_INFINITY = Bytes.repeat((byte) 0, 64);
   private final long gasCost;
 
   private AltBN128MulPrecompiledContract(final GasCalculator gasCalculator, final long gasCost) {
@@ -78,6 +79,12 @@ public long gasRequirement(final Bytes input) {
   @Override
   public PrecompileContractResult computePrecompile(
       final Bytes input, @Nonnull final MessageFrame messageFrame) {
+
+    if (input.size() >= 64 && input.slice(0,64).equals(POINT_AT_INFINITY)) {
+      return new PrecompileContractResult(
+          POINT_AT_INFINITY, false, MessageFrame.State.COMPLETED_SUCCESS, Optional.empty());
+    }
+
     if (useNative) {
       return computeNative(input, messageFrame);
     } else {