From b6a86e2ecbe1a9114e626d4ab1b042c2892ee05a Mon Sep 17 00:00:00 2001
From: Mario <mariorvinas@gmail.com>
Date: Mon, 13 Jan 2025 13:08:51 +0100
Subject: [PATCH] [rhythm] Fix ID generator copy bug (#4540)

* [rhythm] Fix ID generator copy bug

* Add test
---
 modules/blockbuilder/util/id.go      |  2 +-
 modules/blockbuilder/util/id_test.go | 12 ++++++++++++
 2 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/modules/blockbuilder/util/id.go b/modules/blockbuilder/util/id.go
index 6edfb1db837..f9a556a1292 100644
--- a/modules/blockbuilder/util/id.go
+++ b/modules/blockbuilder/util/id.go
@@ -39,7 +39,7 @@ func NewDeterministicIDGenerator(tenantID string, seeds ...uint64) *Deterministi
 func newBuf(tenantID []byte, seeds []uint64) []byte {
 	dl, sl := len(tenantID), len(seeds)
 	data := make([]byte, dl+sl*8+8) // tenantID bytes + 8 bytes per uint64 + 8 bytes for seq
-	copy(tenantID, data)
+	copy(data, tenantID)
 
 	for i, seed := range seeds {
 		binary.LittleEndian.PutUint64(data[dl+i*8:], seed)
diff --git a/modules/blockbuilder/util/id_test.go b/modules/blockbuilder/util/id_test.go
index 42f4d061853..ad59872af71 100644
--- a/modules/blockbuilder/util/id_test.go
+++ b/modules/blockbuilder/util/id_test.go
@@ -36,6 +36,18 @@ func TestDeterministicIDGenerator(t *testing.T) {
 	}
 }
 
+func TestDeterministicIDGeneratorWithDifferentTenants(t *testing.T) {
+	ts := time.Now().UnixMilli()
+	seed := uint64(42)
+
+	gen1 := NewDeterministicIDGenerator("tenant-1", seed, uint64(ts))
+	gen2 := NewDeterministicIDGenerator("tenant-2", seed, uint64(ts))
+
+	for i := 0; i < 10; i++ {
+		assert.NotEqualf(t, gen1.NewID(), gen2.NewID(), "IDs should be different")
+	}
+}
+
 func FuzzDeterministicIDGenerator(f *testing.F) {
 	f.Skip()