From 88a5560ef71a6cd30597df082f35f7f26a350038 Mon Sep 17 00:00:00 2001
From: Rachel Bousfield <nfranks@protonmail.com>
Date: Tue, 30 Jan 2024 00:05:29 -0700
Subject: [PATCH] remove double slicing

---
 arbos/programs/native.go  | 8 +-------
 util/arbmath/bits.go      | 4 ++--
 util/arbmath/math_test.go | 3 ++-
 3 files changed, 5 insertions(+), 10 deletions(-)

diff --git a/arbos/programs/native.go b/arbos/programs/native.go
index d53901e7c..436e94bdb 100644
--- a/arbos/programs/native.go
+++ b/arbos/programs/native.go
@@ -256,13 +256,7 @@ func accountBalanceImpl(api usize, address bytes20, cost *u64) bytes32 {
 func accountCodeImpl(api usize, output *rustBytes, address bytes20, offset u32, size u32, cost *u64) {
 	closures := getApi(api)
 	code, gas := closures.accountCode(address.toAddress(), uint32(offset), uint32(size), uint64(*cost))
-	if int(offset) < len(code) {
-		end := int(offset + size)
-		if len(code) < end {
-			end = len(code)
-		}
-		output.setBytes(code[offset:end])
-	}
+	output.setBytes(code)
 	*cost = u64(gas)
 }
 
diff --git a/util/arbmath/bits.go b/util/arbmath/bits.go
index 14aa1cc03..2cc109588 100644
--- a/util/arbmath/bits.go
+++ b/util/arbmath/bits.go
@@ -89,9 +89,9 @@ func NonNilSlice[T any](slice []T) []T {
 }
 
 // Equivalent to slice[start:offset], but truncates when out of bounds rather than panicking.
-func SliceWithRunoff[S any, I Integer](slice []S, start I, end I) []S {
+func SliceWithRunoff[S any, I Integer](slice []S, start, end I) []S {
 	len := I(len(slice))
-	start = MinInt(start, 0)
+	start = MaxInt(start, 0)
 	end = MaxInt(start, end)
 
 	if slice == nil || start >= len {
diff --git a/util/arbmath/math_test.go b/util/arbmath/math_test.go
index 51da5b23f..2e2f14795 100644
--- a/util/arbmath/math_test.go
+++ b/util/arbmath/math_test.go
@@ -9,6 +9,7 @@ import (
 	"math/rand"
 	"testing"
 
+	"github.com/ethereum/go-ethereum/common"
 	"github.com/offchainlabs/nitro/util/testhelpers"
 )
 
@@ -100,7 +101,7 @@ func TestSlices(t *testing.T) {
 	assert_eq := func(left, right []uint8) {
 		t.Helper()
 		if !bytes.Equal(left, right) {
-			Fail(t)
+			Fail(t, common.Bytes2Hex(left), " ", common.Bytes2Hex(right))
 		}
 	}