From d93a6b486b22dd154ea9feee2796259d384e3991 Mon Sep 17 00:00:00 2001
From: Daniel Lemire <daniel@lemire.me>
Date: Sat, 20 May 2023 17:01:46 -0400
Subject: [PATCH] Verifying issue 386

---
 roaring64/roaring64cow_test.go | 29 +++++++++++++++++++++++++++++
 roaring64/roaringarray64.go    | 13 ++++++++-----
 roaringcow_test.go             | 29 +++++++++++++++++++++++++++++
 3 files changed, 66 insertions(+), 5 deletions(-)

diff --git a/roaring64/roaring64cow_test.go b/roaring64/roaring64cow_test.go
index c88c9c05..b3b7bee9 100644
--- a/roaring64/roaring64cow_test.go
+++ b/roaring64/roaring64cow_test.go
@@ -11,6 +11,35 @@ import (
 	"github.com/stretchr/testify/assert"
 )
 
+func TestIssue386(t *testing.T) {
+	a := NewBitmap()
+	for i := uint64(0); i < 1000; i++ {
+		a.Add(i)
+	}
+	a.SetCopyOnWrite(true)
+	aClone := a.Clone()
+	assert.False(t, a.Contains(1001))
+	assert.EqualValues(t, 1000, a.GetCardinality())
+	assert.EqualValues(t, 1000, aClone.GetCardinality())
+	b := NewBitmap()
+	b.Add(1001)
+	assert.False(t, a.Contains(1001))
+	assert.True(t, b.Contains(1001))
+	assert.EqualValues(t, 1000, a.GetCardinality())
+	assert.EqualValues(t, 1000, aClone.GetCardinality())
+	c := NewBitmap()
+	c.Or(aClone)
+	assert.EqualValues(t, 1000, c.GetCardinality())
+	assert.EqualValues(t, 1000, a.GetCardinality())
+	assert.EqualValues(t, 1000, aClone.GetCardinality())
+	c.Or(b)
+	assert.EqualValues(t, 1001, c.GetCardinality())
+	assert.True(t, c.Contains(1001))
+	assert.False(t, a.Contains(1001))
+	assert.EqualValues(t, 1000, a.GetCardinality())
+	assert.EqualValues(t, 1000, aClone.GetCardinality())
+}
+
 func TestCloneOfCOW(t *testing.T) {
 	rb1 := NewBitmap()
 	rb1.SetCopyOnWrite(true)
diff --git a/roaring64/roaringarray64.go b/roaring64/roaringarray64.go
index 9e3b34bc..446c1884 100644
--- a/roaring64/roaringarray64.go
+++ b/roaring64/roaringarray64.go
@@ -1,6 +1,8 @@
 package roaring64
 
-import "github.com/RoaringBitmap/roaring"
+import (
+	"github.com/RoaringBitmap/roaring"
+)
 
 type roaringArray64 struct {
 	keys            []uint32
@@ -12,9 +14,10 @@ type roaringArray64 struct {
 // runOptimize compresses the element containers to minimize space consumed.
 // Q: how does this interact with copyOnWrite and needCopyOnWrite?
 // A: since we aren't changing the logical content, just the representation,
-//    we don't bother to check the needCopyOnWrite bits. We replace
-//    (possibly all) elements of ra.containers in-place with space
-//    optimized versions.
+//
+//	we don't bother to check the needCopyOnWrite bits. We replace
+//	(possibly all) elements of ra.containers in-place with space
+//	optimized versions.
 func (ra *roaringArray64) runOptimize() {
 	for i := range ra.containers {
 		ra.containers[i].RunOptimize()
@@ -39,7 +42,7 @@ func (ra *roaringArray64) appendCopy(sa roaringArray64, startingindex int) {
 		// since there is no copy-on-write, we need to clone the container (this is important)
 		ra.appendContainer(sa.keys[startingindex], sa.containers[startingindex].Clone(), copyonwrite)
 	} else {
-		ra.appendContainer(sa.keys[startingindex], sa.containers[startingindex], copyonwrite)
+		ra.appendContainer(sa.keys[startingindex], sa.containers[startingindex].Clone(), copyonwrite)
 		if !sa.needsCopyOnWrite(startingindex) {
 			sa.setNeedsCopyOnWrite(startingindex)
 		}
diff --git a/roaringcow_test.go b/roaringcow_test.go
index 09573804..94d07acb 100644
--- a/roaringcow_test.go
+++ b/roaringcow_test.go
@@ -10,6 +10,35 @@ import (
 	"github.com/stretchr/testify/assert"
 )
 
+func TestIssue386(t *testing.T) {
+	a := NewBitmap()
+	for i := uint32(0); i < 1000; i++ {
+		a.Add(i)
+	}
+	a.SetCopyOnWrite(true)
+	aClone := a.Clone()
+	assert.False(t, a.Contains(1001))
+	assert.EqualValues(t, 1000, a.GetCardinality())
+	assert.EqualValues(t, 1000, aClone.GetCardinality())
+	b := NewBitmap()
+	b.Add(1001)
+	assert.False(t, a.Contains(1001))
+	assert.True(t, b.Contains(1001))
+	assert.EqualValues(t, 1000, a.GetCardinality())
+	assert.EqualValues(t, 1000, aClone.GetCardinality())
+	c := NewBitmap()
+	c.Or(aClone)
+	assert.EqualValues(t, 1000, c.GetCardinality())
+	assert.EqualValues(t, 1000, a.GetCardinality())
+	assert.EqualValues(t, 1000, aClone.GetCardinality())
+	c.Or(b)
+	assert.EqualValues(t, 1001, c.GetCardinality())
+	assert.True(t, c.Contains(1001))
+	assert.False(t, a.Contains(1001))
+	assert.EqualValues(t, 1000, a.GetCardinality())
+	assert.EqualValues(t, 1000, aClone.GetCardinality())
+}
+
 func TestCloneOfCOW(t *testing.T) {
 	rb1 := NewBitmap()
 	rb1.SetCopyOnWrite(true)