Bundled Theme: Load Google fonts with `display=fallback` parameter for better UX in case the font cannot be loaded.

Providing this query parameter ensures the stylesheet contains the `font-display: fallback` rule. This changeset also updates the Open Sans font used by core accordingly.

Props westonruter.
Fixes #47282.

Built from https://develop.svn.wordpress.org/trunk@45485


git-svn-id: http://core.svn.wordpress.org/trunk@45296 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-content/themes/twentyfifteen/functions.php

@@ -333,6 +333,7 @@ if ( ! function_exists( 'twentyfifteen_fonts_url' ) ) :
 				array(
 					'family'  => urlencode( implode( '|', $fonts ) ),
 					'subset'  => urlencode( $subsets ),
+					'display' => urlencode( 'fallback' ),
 				),
 				'https://fonts.googleapis.com/css'
 			);

wp-content/themes/twentyfourteen/functions.php

@@ -296,6 +296,7 @@ function twentyfourteen_font_url() {
 		$query_args = array(
 			'family'  => urlencode( 'Lato:300,400,700,900,300italic,400italic,700italic' ),
 			'subset'  => urlencode( 'latin,latin-ext' ),
+			'display' => urlencode( 'fallback' ),
 		);
 		$font_url   = add_query_arg( $query_args, 'https://fonts.googleapis.com/css' );
 	}

wp-content/themes/twentyseventeen/functions.php

@@ -296,6 +296,7 @@ function twentyseventeen_fonts_url() {
 		$query_args = array(
 			'family'  => urlencode( implode( '|', $font_families ) ),
 			'subset'  => urlencode( 'latin,latin-ext' ),
+			'display' => urlencode( 'fallback' ),
 		);
 
 		$fonts_url = add_query_arg( $query_args, 'https://fonts.googleapis.com/css' );

wp-content/themes/twentysixteen/functions.php

@@ -333,6 +333,7 @@ if ( ! function_exists( 'twentysixteen_fonts_url' ) ) :
 				array(
 					'family'  => urlencode( implode( '|', $fonts ) ),
 					'subset'  => urlencode( $subsets ),
+					'display' => urlencode( 'fallback' ),
 				),
 				'https://fonts.googleapis.com/css'
 			);

wp-content/themes/twentythirteen/functions.php

@@ -245,6 +245,7 @@ function twentythirteen_fonts_url() {
 		$query_args = array(
 			'family'  => urlencode( implode( '|', $font_families ) ),
 			'subset'  => urlencode( 'latin,latin-ext' ),
+			'display' => urlencode( 'fallback' ),
 		);
 		$fonts_url  = add_query_arg( $query_args, 'https://fonts.googleapis.com/css' );
 	}

wp-content/themes/twentytwelve/functions.php

@@ -165,8 +165,9 @@ function twentytwelve_get_font_url() {
 		}
 
 		$query_args = array(
-			'family' => 'Open+Sans:400italic,700italic,400,700',
-			'subset' => $subsets,
+			'family'  => urlencode( 'Open+Sans:400italic,700italic,400,700' ),
+			'subset'  => urlencode( $subsets ),
+			'display' => urlencode( 'fallback' ),
 		);
 		$font_url   = add_query_arg( $query_args, 'https://fonts.googleapis.com/css' );
 	}

wp-includes/script-loader.php

@@ -1919,7 +1919,7 @@ function wp_default_styles( &$styles ) {
 		}
 
 		// Hotlink Open Sans, for now
-		$open_sans_font_url = "https://fonts.googleapis.com/css?family=Open+Sans:300italic,400italic,600italic,300,400,600&subset=$subsets";
+		$open_sans_font_url = "https://fonts.googleapis.com/css?family=Open+Sans:300italic,400italic,600italic,300,400,600&subset=$subsets&display=fallback";
 	}
 
 	// Register a stylesheet for the selected admin color scheme.

wp-includes/version.php

@@ -13,7 +13,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '5.3-alpha-45484';
+$wp_version = '5.3-alpha-45485';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.