fix: collections test IterateRaw bug (#24737)

collections/CHANGELOG.md

@@ -31,6 +31,12 @@ Ref: https://keepachangelog.com/en/1.0.0/
 
 ## [Unreleased]
 
+## [v1.2.1](https://github.com/cosmos/cosmos-sdk/releases/tag/collections%2Fv1.2.1)
+
+## Bug Fixes
+
+* [#24737](https://github.com/cosmos/cosmos-sdk/pull/24737) Ensure that map memory will never be reused unintentionally.
+
 ## [v1.2.0](https://github.com/cosmos/cosmos-sdk/releases/tag/collections%2Fv1.2.0)
 
 ### Improvements

collections/map.go

@@ -223,6 +223,14 @@ func deleteDomain(s store.KVStore, start, end []byte) error {
 	return nil
 }
 
+// concatNew concatenates two byte slices, prefix and suffix, into a new byte slice and returns the result.
+func concatNew(prefix, suffix []byte) []byte {
+	b := make([]byte, len(prefix)+len(suffix))
+	copy(b, prefix)
+	copy(b[len(prefix):], suffix)
+	return b
+}
+
 // IterateRaw iterates over the collection. The iteration range is untyped, it uses raw
 // bytes. The resulting Iterator is typed.
 // A nil start iterates from the first key contained in the collection.
@@ -230,12 +238,12 @@ func deleteDomain(s store.KVStore, start, end []byte) error {
 // A nil start and a nil end iterates over every key contained in the collection.
 // TODO(tip): simplify after https://github.com/cosmos/cosmos-sdk/pull/14310 is merged
 func (m Map[K, V]) IterateRaw(ctx context.Context, start, end []byte, order Order) (Iterator[K, V], error) {
-	prefixedStart := append(m.prefix, start...)
+	prefixedStart := concatNew(m.prefix, start)
 	var prefixedEnd []byte
 	if end == nil {
 		prefixedEnd = nextBytesPrefixKey(m.prefix)
 	} else {
-		prefixedEnd = append(m.prefix, end...)
+		prefixedEnd = concatNew(m.prefix, end)
 	}
 
 	if bytes.Compare(prefixedStart, prefixedEnd) == 1 {

collections/map_test.go

@@ -127,3 +127,33 @@ func Test_encodeKey(t *testing.T) {
 	require.NoError(t, err)
 	require.Equal(t, expectedKey, gotKey)
 }
+
+func TestMap_IterateRaw_Prefix(t *testing.T) {
+	sk, ctx := deps()
+	// safety check to ensure prefix boundaries are not crossed
+	require.NoError(t, sk.OpenKVStore(ctx).Set([]byte{0x0, 0x0}, []byte("before prefix")))
+	require.NoError(t, sk.OpenKVStore(ctx).Set([]byte{0x2, 0x0}, []byte("after prefix")))
+	sb := NewSchemaBuilder(sk)
+	// case 1. this is abnormal but easy to understand the problem
+	// prefix := make([]byte, 0, 10)
+	// prefix = append(prefix, 1)
+	// case 2. this is more common case, some modules can use this way
+	prefix := []byte{}
+	prefix = append(append(prefix, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10), 1, 2, 3, 4, 5, 6, 7, 8, 9, 10)
+	t.Log(cap(prefix)) // cap is 32
+	m := NewMap(sb, prefix, "m", Uint64Key, Uint64Value)
+	require.NoError(t, m.Set(ctx, 0, 0))
+	require.NoError(t, m.Set(ctx, 1, 1))
+	require.NoError(t, m.Set(ctx, 2, 2))
+	// test non nil end in ascending order
+	oneBigEndian, err := EncodeKeyWithPrefix(nil, Uint64Key, 1)
+	require.NoError(t, err)
+	twoBigEndian, err := EncodeKeyWithPrefix(nil, Uint64Key, 2)
+	require.NoError(t, err)
+	iter, err := m.IterateRaw(ctx, oneBigEndian, twoBigEndian, OrderAscending)
+	require.NoError(t, err)
+	defer iter.Close()
+	keys, err := iter.Keys()
+	require.NoError(t, err)
+	require.Equal(t, []uint64{1}, keys)
+}