Ticket #39331: 39331.patch

src/wp-includes/class-wp-image-editor-imagick.php

@@ -367 +367 @@
 
                         // Set appropriate quality settings after resizing.
                         if ( 'image/jpeg' == $this->mime_type ) {
-                                if ( is_callable( array( $this->image, 'unsharpMaskImage' ) ) ) {
+                                // Not compatible with CMYK color spaces.
+                                if ( is_callable( array( $this->image, 'unsharpMaskImage' ) && Imagick::COLORSPACE_CMYK !== $this->image->getImageColorspace() ) ) {
                                         $this->image->unsharpMaskImage( 0.25, 0.25, 8, 0.065 );
                                 }
 

tests/phpunit/tests/image/editor_imagick.php

@@ -542 +542 @@
 
                 $this->assertTrue( $result );
         }
+
+        /**
+         * @ticket 39331
+         */
+        public function test_cmyk_jpg_resize() {
+                $test_file = DIR_TESTDATA . '/images/test_cmyk.jpg';
+                $save_to_file = tempnam( get_temp_dir(), '' ) . '.jpg';
+
+                $editor = new WP_Image_Editor_Imagick( $test_file );
+                $editor->load();
+                $editor->resize( 106, 150 ); // Default thumbnail size.
+                $editor->save( $save_to_file );
+
+                // Use GD as Imagick seems to do some color mapping of CMYK images.
+                $gd_image = imagecreatefromjpeg( $save_to_file );
+                // Not sure how system-independent this is.
+                // Pixel (15, 10) should be white.
+                $output = dechex( imagecolorat( $gd_image, 15, 10 ) );
+                imagedestroy( $gd_image );
+                $this->assertSame( 'ffffff', $output );
+
+                unlink( $save_to_file );
+        }
 }