Fix WebP handling when editing images based on WordPress 6.3 change

modules/images/webp-uploads/image-edit.php

@@ -131,7 +131,7 @@ static function ( $metadata, $post_meta_id ) use ( $post_id, $file_path, $mime_t
 
 			foreach ( $old_metadata['sizes'] as $size_name => $size_details ) {
 				// If the target is 'nothumb', skip generating the 'thumbnail' size.
-				if ( 'nothumb' === $target && 'thumbnail' === $size_name ) {
+				if ( webp_uploads_image_edit_thumbnails_separately() && 'nothumb' === $target && 'thumbnail' === $size_name ) {
 					continue;
 				}
 
@@ -150,7 +150,7 @@ static function ( $metadata, $post_meta_id ) use ( $post_id, $file_path, $mime_t
 			foreach ( $mime_transforms as $targeted_mime ) {
 				if ( $targeted_mime === $mime_type ) {
 					// If the target is `thumbnail` make sure it is the only selected size.
-					if ( 'thumbnail' === $target ) {
+					if ( webp_uploads_image_edit_thumbnails_separately() && 'thumbnail' === $target ) {
 						if ( isset( $metadata['sizes']['thumbnail'] ) ) {
 							$subsized_images[ $targeted_mime ] = array( 'thumbnail' => $metadata['sizes']['thumbnail'] );
 						}
@@ -178,7 +178,7 @@ static function ( $metadata, $post_meta_id ) use ( $post_id, $file_path, $mime_t
 				$extension = $extension[0];
 
 				// If the target is `thumbnail` make sure only that size is generated.
-				if ( 'thumbnail' === $target ) {
+				if ( webp_uploads_image_edit_thumbnails_separately() && 'thumbnail' === $target ) {
 					if ( ! isset( $subsized_images[ $mime_type ]['thumbnail']['file'] ) ) {
 						continue;
 					}
@@ -287,7 +287,7 @@ function webp_uploads_backup_sources( $attachment_id, $data ) {
 	$target = isset( $_REQUEST['target'] ) ? sanitize_key( $_REQUEST['target'] ) : 'all';
 
 	// When an edit to an image is only applied to a thumbnail there's nothing we need to back up.
-	if ( 'thumbnail' === $target ) {
+	if ( webp_uploads_image_edit_thumbnails_separately() && 'thumbnail' === $target ) {
 		return $data;
 	}
 
@@ -420,3 +420,26 @@ function webp_uploads_restore_image( $attachment_id, $data ) {
 
 	return $data;
 }
+
+/**
+ * Compatibility function to check whether editing image thumbnails separately is enabled.
+ *
+ * The filter {@see 'image_edit_thumbnails_separately'} was introduced in WordPress 6.3 with default value of `false`,
+ * for a behavior that previously was always enabled.
+ *
+ * @since n.e.x.t
+ * @see https://core.trac.wordpress.org/ticket/57685
+ *
+ * @return bool True if editing image thumbnails is enabled, false otherwise.
+ */
+function webp_uploads_image_edit_thumbnails_separately() {
+	if ( version_compare( get_bloginfo( 'version' ), '6.3', '<' ) ) {
+		return true;
+	}
+
+	/*
+	 * This filter was introduced in WordPress 6.3 with default value `false`,
+	 * thus changing the behavior of several image editing functions.
+	 */
+	return apply_filters( 'image_edit_thumbnails_separately', false );
+}

tests/modules/images/fetchpriority/fetchpriority-tests.php

@@ -37,11 +37,15 @@ public static function tear_down_after_class() {
 		parent::tear_down_after_class();
 	}
 
-	public function test_fetchpriority_img_tag_add_attr_based_on_context_and_loading_lazy() {
-		if ( version_compare( get_bloginfo( 'version' ), '6.3', '>=' ) ) {
-			$this->markTestSkipped( 'Fetchpriority module no longer relevant with WordPress 6.3 shipping with the feature' );
+	public function set_up() {
+		parent::set_up();
+
+		if ( ! perflab_can_load_module( 'images/fetchpriority' ) ) {
+			$this->markTestSkipped( 'Fetchpriority module tests irrelevant since available in WordPress core' );
 		}
+	}
 
+	public function test_fetchpriority_img_tag_add_attr_based_on_context_and_loading_lazy() {
 		$img = get_image_tag( self::$attachment_id, '', '', '', 'large' );
 
 		$this->assertStringContainsString( 'fetchpriority="high"', fetchpriority_img_tag_add_attr( $img, 'the_content' ) );
@@ -52,10 +56,6 @@ public function test_fetchpriority_img_tag_add_attr_based_on_context_and_loading
 	}
 
 	public function test_fetchpriority_img_tag_add_in_wp_filter_content_tags() {
-		if ( version_compare( get_bloginfo( 'version' ), '6.3', '>=' ) ) {
-			$this->markTestSkipped( 'Fetchpriority module no longer relevant with WordPress 6.3 shipping with the feature' );
-		}
-
 		global $wp_query;
 		global $wp_the_query;
 		$img   = get_image_tag( self::$attachment_id, '', '', '', 'large' );

tests/modules/images/webp-uploads/image-edit-tests.php

@@ -144,6 +144,10 @@ public function it_should_prevent_to_back_up_the_sources_when_the_sources_attrib
 	 * @test
 	 */
 	public function it_should_prevent_to_backup_the_full_size_image_if_only_the_thumbnail_is_edited() {
+		if ( ! webp_uploads_image_edit_thumbnails_separately() ) {
+			$this->markTestSkipped( 'Editing image thumbnails separately is disabled' );
+		}
+
 		// Create JPEG and WebP.
 		$this->opt_in_to_jpeg_and_webp();
 
@@ -195,6 +199,10 @@ public function it_should_prevent_to_backup_the_full_size_image_if_only_the_thum
 	 * @test
 	 */
 	public function it_should_backup_the_image_when_all_images_except_the_thumbnail_are_updated() {
+		if ( ! webp_uploads_image_edit_thumbnails_separately() ) {
+			$this->markTestSkipped( 'Editing image thumbnails separately is disabled' );
+		}
+
 		$attachment_id = self::factory()->attachment->create_upload_object( TESTS_PLUGIN_DIR . '/tests/testdata/modules/images/leafs.jpg' );
 		$metadata      = wp_get_attachment_metadata( $attachment_id );
 
@@ -236,6 +244,10 @@ public function it_should_backup_the_image_when_all_images_except_the_thumbnail_
 	 * @test
 	 */
 	public function it_should_use_the_attached_image_when_updating_subsequent_images_not_the_original_version() {
+		if ( ! webp_uploads_image_edit_thumbnails_separately() ) {
+			$this->markTestSkipped( 'Editing image thumbnails separately is disabled' );
+		}
+
 		// The leafs image is 1080 pixels wide with this filter we ensure a -scaled version is created for this test.
 		add_filter(
 			'big_image_size_threshold',