From a7dda351333fd4639a920774cac1260277e2ea38 Mon Sep 17 00:00:00 2001 From: Felix Arntz Date: Mon, 18 Nov 2024 19:52:19 +0000 Subject: [PATCH] Media: Avoid images with `sizes=auto` to be displayed downsized in supporting browsers. Based on the user agent stylesheet rules outlined in https://html.spec.whatwg.org/multipage/rendering.html#img-contain-size, images that have `sizes=auto` while applying `width: auto` or `width: fit-content` would be constrained to only 300px width. This changeset overrides said user agent stylesheet rule with a much larger constraint, to avoid the problem. Additionally, it introduces a filter `wp_img_tag_add_auto_sizes` which can be used to opt out of the functionality, as an additional measure. Props joemcgill, flixos90, dooperweb, SirLouen, azaozz, mukesh27, apermo. Fixes #62413. See #61847, #62345. Built from https://develop.svn.wordpress.org/trunk@59415 git-svn-id: http://core.svn.wordpress.org/trunk@58801 1a063a9b-81f0-0310-95a4-ce76da25c4cd --- wp-includes/default-filters.php | 1 + wp-includes/media.php | 52 +++++++++++++++++++++++++++++++-- wp-includes/version.php | 2 +- 3 files changed, 52 insertions(+), 3 deletions(-) diff --git a/wp-includes/default-filters.php b/wp-includes/default-filters.php index 961b37f9aa..ae654605e8 100644 --- a/wp-includes/default-filters.php +++ b/wp-includes/default-filters.php @@ -611,6 +611,7 @@ add_action( 'wp_footer', 'wp_enqueue_stored_styles', 1 ); add_action( 'wp_default_styles', 'wp_default_styles' ); add_filter( 'style_loader_src', 'wp_style_loader_src', 10, 2 ); +add_action( 'wp_head', 'wp_print_auto_sizes_contain_css_fix', 1 ); add_action( 'wp_head', 'wp_maybe_inline_styles', 1 ); // Run for styles enqueued in . add_action( 'wp_footer', 'wp_maybe_inline_styles', 1 ); // Run for late-loaded styles in the footer. diff --git a/wp-includes/media.php b/wp-includes/media.php index 6e58658189..00e23ff53d 100644 --- a/wp-includes/media.php +++ b/wp-includes/media.php @@ -1137,8 +1137,12 @@ function wp_get_attachment_image( $attachment_id, $size = 'thumbnail', $icon = f } } + /** This filter is documented in wp-includes/media.php */ + $add_auto_sizes = apply_filters( 'wp_img_tag_add_auto_sizes', true ); + // Adds 'auto' to the sizes attribute if applicable. if ( + $add_auto_sizes && isset( $attr['loading'] ) && 'lazy' === $attr['loading'] && isset( $attr['sizes'] ) && @@ -1985,6 +1989,17 @@ function wp_filter_content_tags( $content, $context = null ) { * @return string The filtered image tag markup. */ function wp_img_tag_add_auto_sizes( string $image ): string { + /** + * Filters whether auto-sizes for lazy loaded images is enabled. + * + * @since 6.7.1 + * + * @param boolean $enabled Whether auto-sizes for lazy loaded images is enabled. + */ + if ( ! apply_filters( 'wp_img_tag_add_auto_sizes', true ) ) { + return $image; + } + $processor = new WP_HTML_Tag_Processor( $image ); // Bail if there is no IMG tag. @@ -1993,8 +2008,19 @@ function wp_img_tag_add_auto_sizes( string $image ): string { } // Bail early if the image is not lazy-loaded. - $value = $processor->get_attribute( 'loading' ); - if ( ! is_string( $value ) || 'lazy' !== strtolower( trim( $value, " \t\f\r\n" ) ) ) { + $loading = $processor->get_attribute( 'loading' ); + if ( ! is_string( $loading ) || 'lazy' !== strtolower( trim( $loading, " \t\f\r\n" ) ) ) { + return $image; + } + + /* + * Bail early if the image doesn't have a width attribute. + * Per WordPress Core itself, lazy-loaded images should always have a width attribute. + * However, it is possible that lazy-loading could be added by a plugin, where we don't have that guarantee. + * As such, it still makes sense to ensure presence of a width attribute here in order to use `sizes=auto`. + */ + $width = $processor->get_attribute( 'width' ); + if ( ! is_string( $width ) || '' === $width ) { return $image; } @@ -2029,6 +2055,28 @@ function wp_sizes_attribute_includes_valid_auto( string $sizes_attr ): bool { return 'auto' === strtolower( trim( $first_size, " \t\f\r\n" ) ); } +/** + * Prints a CSS rule to fix potential visual issues with images using `sizes=auto`. + * + * This rule overrides the similar rule in the default user agent stylesheet, to avoid images that use e.g. + * `width: auto` or `width: fit-content` to appear smaller. + * + * @since 6.7.1 + * @see https://html.spec.whatwg.org/multipage/rendering.html#img-contain-size + * @see https://core.trac.wordpress.org/ticket/62413 + */ +function wp_print_auto_sizes_contain_css_fix() { + /** This filter is documented in wp-includes/media.php */ + $add_auto_sizes = apply_filters( 'wp_img_tag_add_auto_sizes', true ); + if ( ! $add_auto_sizes ) { + return; + } + + ?> + +