From b236ce7a9a5a409d91cb8f647b836062184e81f0 Mon Sep 17 00:00:00 2001
From: MrChico <martin.lundfall@protonmail.com>
Date: Wed, 13 May 2020 15:46:58 +0200
Subject: [PATCH] Defensive handling of dead path (#13)

---
 deposit_contract.sol | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/deposit_contract.sol b/deposit_contract.sol
index 81c33a288..a94e8fbf0 100644
--- a/deposit_contract.sol
+++ b/deposit_contract.sol
@@ -121,11 +121,14 @@ contract DepositContract is IDepositContract {
         for (uint height = 0; height < DEPOSIT_CONTRACT_TREE_DEPTH; height++) {
             if ((size & 1) == 1) {
                 branch[height] = node;
-                break;
+                return;
             }
             node = sha256(abi.encodePacked(branch[height], node));
             size /= 2;
         }
+        // As the loop should always end prematurely with the `return` statement,
+        // this code should be unreachable. We assert `false` just to be safe.
+        assert(false);
     }
 
     function to_little_endian_64(uint64 value) internal pure returns (bytes memory ret) {