From 3c754e2a09d112cd62f4d51f221637f9a147dcc6 Mon Sep 17 00:00:00 2001
From: Jordan Krage <jmank88@gmail.com>
Date: Mon, 25 Nov 2024 06:34:50 -0600
Subject: [PATCH] accounts/abi:  fix MakeTopics mutation of big.Int inputs
 (#30785)

#28764 updated `func MakeTopics` to support negative `*big.Int`s.
However, it also changed the behavior of the function from just
_reading_ the input `*big.Int` via `Bytes()`, to leveraging
`big.U256Bytes` which is documented as being _destructive_:

This change updates `MakeTopics` to not mutate the original, and
also applies the same change in signer/core/apitypes.
---
 accounts/abi/topics.go        |  2 +-
 accounts/abi/topics_test.go   | 17 +++++++++++++++++
 signer/core/apitypes/types.go |  2 +-
 3 files changed, 19 insertions(+), 2 deletions(-)

diff --git a/accounts/abi/topics.go b/accounts/abi/topics.go
index 7ce9b7273c..4819334ae6 100644
--- a/accounts/abi/topics.go
+++ b/accounts/abi/topics.go
@@ -42,7 +42,7 @@ func MakeTopics(query ...[]interface{}) ([][]common.Hash, error) {
 			case common.Address:
 				copy(topic[common.HashLength-common.AddressLength:], rule[:])
 			case *big.Int:
-				copy(topic[:], math.U256Bytes(rule))
+				copy(topic[:], math.U256Bytes(new(big.Int).Set(rule)))
 			case bool:
 				if rule {
 					topic[common.HashLength-1] = 1
diff --git a/accounts/abi/topics_test.go b/accounts/abi/topics_test.go
index 6a4c50078a..161867e2d9 100644
--- a/accounts/abi/topics_test.go
+++ b/accounts/abi/topics_test.go
@@ -149,6 +149,23 @@ func TestMakeTopics(t *testing.T) {
 			}
 		})
 	}
+
+	t.Run("does not mutate big.Int", func(t *testing.T) {
+		t.Parallel()
+		want := [][]common.Hash{{common.HexToHash("ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff")}}
+
+		in := big.NewInt(-1)
+		got, err := MakeTopics([]interface{}{in})
+		if err != nil {
+			t.Fatalf("makeTopics() error = %v", err)
+		}
+		if !reflect.DeepEqual(got, want) {
+			t.Fatalf("makeTopics() = %v, want %v", got, want)
+		}
+		if orig := big.NewInt(-1); in.Cmp(orig) != 0 {
+			t.Fatalf("makeTopics() mutated an input parameter from %v to %v", orig, in)
+		}
+	})
 }
 
 type args struct {
diff --git a/signer/core/apitypes/types.go b/signer/core/apitypes/types.go
index 2ae182279a..b56931c1d1 100644
--- a/signer/core/apitypes/types.go
+++ b/signer/core/apitypes/types.go
@@ -676,7 +676,7 @@ func (typedData *TypedData) EncodePrimitiveValue(encType string, encValue interf
 		if err != nil {
 			return nil, err
 		}
-		return math.U256Bytes(b), nil
+		return math.U256Bytes(new(big.Int).Set(b)), nil
 	}
 	return nil, fmt.Errorf("unrecognized type '%s'", encType)
 }