From f14536cfbda4000a4cf7a5a0c147b46b760b8db8 Mon Sep 17 00:00:00 2001
From: thedavidmeister <thedavidmeister@gmail.com>
Date: Sun, 11 Aug 2024 16:36:32 +0400
Subject: [PATCH] round outputs up on diffs

---
 src/concrete/ob/OrderBook.sol | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/concrete/ob/OrderBook.sol b/src/concrete/ob/OrderBook.sol
index 0d0e68482..dbf0353b0 100644
--- a/src/concrete/ob/OrderBook.sol
+++ b/src/concrete/ob/OrderBook.sol
@@ -872,7 +872,11 @@ contract OrderBook is IOrderBookV4, IMetaV1_2, ReentrancyGuard, Multicall, Order
             LibFixedPointDecimalScale.scale18(
                 output,
                 orderIOCalculation.context[CONTEXT_VAULT_OUTPUTS_COLUMN][CONTEXT_VAULT_IO_TOKEN_DECIMALS] / 1e18,
-                0
+                // Round outputs diff up if the scaling causes a rounding error.
+                // This only happens if the token has more than 18 decimals.
+                // Generally it's safer to overestimate output than
+                // underestimate.
+                FLAG_ROUND_UP
             );
         }