From 6926256b719269f340681d6d59ddc44e1cb0356f Mon Sep 17 00:00:00 2001
From: Vadim Kulagin <10106384+VadimKulagin@users.noreply.github.com>
Date: Wed, 27 Dec 2023 17:53:43 +0300
Subject: [PATCH] Allocate new(big.Int) in Copy method to deeply clone it
 (#278)

---
 decimal.go      | 2 +-
 decimal_test.go | 4 ++++
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/decimal.go b/decimal.go
index c614ea7..5982f81 100644
--- a/decimal.go
+++ b/decimal.go
@@ -418,7 +418,7 @@ func NewFromFloatWithExponent(value float64, exp int32) Decimal {
 func (d Decimal) Copy() Decimal {
 	d.ensureInitialized()
 	return Decimal{
-		value: &(*d.value),
+		value: new(big.Int).Set(d.value),
 		exp:   d.exp,
 	}
 }
diff --git a/decimal_test.go b/decimal_test.go
index 2b3a99e..c6d2b24 100644
--- a/decimal_test.go
+++ b/decimal_test.go
@@ -560,6 +560,10 @@ func TestCopy(t *testing.T) {
 	origin := New(1, 0)
 	cpy := origin.Copy()
 
+	if origin.value == cpy.value {
+		t.Error("expecting copy and origin to have different value pointers")
+	}
+
 	if cpy.Cmp(origin) != 0 {
 		t.Error("expecting copy and origin to be equals, but they are not")
 	}