From 1c9557d5435122a54a2d8a0649f74925dd1cd3e8 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Miloslav=20Trma=C4=8D?= <mitr@redhat.com>
Date: Fri, 15 Mar 2024 22:33:11 +0100
Subject: [PATCH] Detect zstd:chunked format in source blobs
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

... instead of only treating it as zstd.

Signed-off-by: Miloslav Trmač <mitr@redhat.com>
---
 copy/compression.go | 10 ++++++++++
 copy/single.go      |  2 +-
 2 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/copy/compression.go b/copy/compression.go
index cfb4c8d107..fb5e1b174e 100644
--- a/copy/compression.go
+++ b/copy/compression.go
@@ -52,6 +52,16 @@ func blobPipelineDetectCompressionStep(stream *sourceStream, srcInfo types.BlobI
 	}
 	stream.reader = reader
 
+	if decompressor != nil && format.Name() == compressiontypes.ZstdAlgorithmName {
+		tocDigest, err := chunkedToc.GetTOCDigest(srcInfo.Annotations)
+		if err != nil {
+			return bpDetectCompressionStepData{}, err
+		}
+		if tocDigest != nil {
+			format = compression.ZstdChunked
+		}
+
+	}
 	res := bpDetectCompressionStepData{
 		isCompressed: decompressor != nil,
 		format:       format,
diff --git a/copy/single.go b/copy/single.go
index d70c928557..ba414a22d6 100644
--- a/copy/single.go
+++ b/copy/single.go
@@ -163,7 +163,7 @@ func (c *copier) copySingleImage(ctx context.Context, unparsedImage *image.Unpar
 		if format == nil {
 			format = defaultCompressionFormat
 		}
-		if format.Name() == compression.ZstdChunked.Name() {
+		if format.Name() == compressiontypes.ZstdChunkedAlgorithmName {
 			if ic.requireCompressionFormatMatch {
 				return copySingleImageResult{}, errors.New("explicitly requested to combine zstd:chunked with encryption, which is not beneficial; use plain zstd instead")
 			}