From dd9c8ccacb661344587f700fd8b896b8872369fc Mon Sep 17 00:00:00 2001
From: Alexander McFarlane <alexander.mcfarlane@physics.org>
Date: Fri, 7 Apr 2023 06:55:18 +0100
Subject: [PATCH] fixes an issue where pairing raises an unexpected exception
 due to success=0x0 having odd length

---
 templates/verifier_groth16.sol.ejs | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/templates/verifier_groth16.sol.ejs b/templates/verifier_groth16.sol.ejs
index 707b2b54..15ba71f6 100644
--- a/templates/verifier_groth16.sol.ejs
+++ b/templates/verifier_groth16.sol.ejs
@@ -107,10 +107,9 @@ library Pairing {
         uint[1] memory out;
         bool success;
         // solium-disable-next-line security/no-inline-assembly
+        // precompiled bn128 curve pairing as per EIP197 - defined as contract "8"
         assembly {
             success := staticcall(sub(gas(), 2000), 8, add(input, 0x20), mul(inputSize, 0x20), out, 0x20)
-            // Use "invalid" to make gas estimation work
-            switch success case 0 { invalid() }
         }
         require(success,"pairing-opcode-failed");
         return out[0] != 0;