From fb70fbb09ff76440124b1fad567c39bd2997cc99 Mon Sep 17 00:00:00 2001
From: Lovell Fuller <github@lovell.info>
Date: Sun, 11 Feb 2024 20:10:18 +0000
Subject: [PATCH] Ensure keepIccProfile retains CMYK input profiles #3906

---
 docs/changelog.md     |  5 +++++
 src/pipeline.cc       |  2 +-
 test/unit/metadata.js | 13 +++++++++++++
 3 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/docs/changelog.md b/docs/changelog.md
index cb682b0c..8f80eddc 100644
--- a/docs/changelog.md
+++ b/docs/changelog.md
@@ -4,6 +4,11 @@
 
 Requires libvips v8.15.1
 
+### v0.33.3 - TBD
+
+* Ensure `keepIccProfile` retains CMYK input profiles.
+  [#3906](https://github.com/lovell/sharp/issues/3906)
+
 ### v0.33.2 - 12th January 2024
 
 * Upgrade to libvips v8.15.1 for upstream bug fixes.
diff --git a/src/pipeline.cc b/src/pipeline.cc
index 791f208b..b4d587b0 100644
--- a/src/pipeline.cc
+++ b/src/pipeline.cc
@@ -776,7 +776,7 @@ class PipelineWorker : public Napi::AsyncWorker {
         // Convert colourspace, pass the current known interpretation so libvips doesn't have to guess
         image = image.colourspace(baton->colourspace, VImage::option()->set("source_space", image.interpretation()));
         // Transform colours from embedded profile to output profile
-        if ((baton->keepMetadata & VIPS_FOREIGN_KEEP_ICC) &&
+        if ((baton->keepMetadata & VIPS_FOREIGN_KEEP_ICC) && baton->colourspaceInput != VIPS_INTERPRETATION_CMYK &&
           baton->withIccProfile.empty() && sharp::HasProfile(image)) {
           image = image.icc_transform("srgb", VImage::option()
             ->set("embedded", TRUE)
diff --git a/test/unit/metadata.js b/test/unit/metadata.js
index 820868dd..09de787c 100644
--- a/test/unit/metadata.js
+++ b/test/unit/metadata.js
@@ -576,6 +576,19 @@ describe('Image metadata', function () {
     assert.strictEqual(description, 'Generic RGB Profile');
   });
 
+  it('keep existing CMYK ICC profile', async () => {
+    const data = await sharp(fixtures.inputJpgWithCmykProfile)
+      .pipelineColourspace('cmyk')
+      .toColourspace('cmyk')
+      .keepIccProfile()
+      .toBuffer();
+
+    const metadata = await sharp(data).metadata();
+    assert.strictEqual(metadata.channels, 4);
+    const { description } = icc.parse(metadata.icc);
+    assert.strictEqual(description, 'U.S. Web Coated (SWOP) v2');
+  });
+
   it('transform to ICC profile and attach', async () => {
     const data = await sharp({ create })
       .png()