From 35a627df49ddff6a6067bb7100fc8973cbd0f0b8 Mon Sep 17 00:00:00 2001
From: Owen Diehl <ow.diehl@gmail.com>
Date: Tue, 1 Dec 2020 08:37:06 -0500
Subject: [PATCH] adds the ability to read chunkFormatV3 while writing v2
 (#2984)

(cherry picked from commit a8af1c0c84a18192d0c3fb04dc1634cedc8fd078)
---
 pkg/chunkenc/memchunk.go      | 2 +-
 pkg/chunkenc/memchunk_test.go | 1 +
 2 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/pkg/chunkenc/memchunk.go b/pkg/chunkenc/memchunk.go
index 364797e2b301..999cddf29c9a 100644
--- a/pkg/chunkenc/memchunk.go
+++ b/pkg/chunkenc/memchunk.go
@@ -166,7 +166,7 @@ func NewMemChunk(enc Encoding, blockSize, targetSize int) *MemChunk {
 		blocks:     []block{},
 
 		head:   &headBlock{},
-		format: chunkFormatV3,
+		format: chunkFormatV2,
 
 		encoding: enc,
 	}
diff --git a/pkg/chunkenc/memchunk_test.go b/pkg/chunkenc/memchunk_test.go
index fa3f8e2b280e..b343a4d754b5 100644
--- a/pkg/chunkenc/memchunk_test.go
+++ b/pkg/chunkenc/memchunk_test.go
@@ -256,6 +256,7 @@ func TestRoundtripV3(t *testing.T) {
 	for _, enc := range testEncoding {
 		t.Run(enc.String(), func(t *testing.T) {
 			c := NewMemChunk(enc, testBlockSize, testTargetSize)
+			c.format = chunkFormatV3
 			_ = fillChunk(c)
 
 			b, err := c.Bytes()