Block Editor: Do not load a default font family for themes with theme…

….json.

This matches the behavior that has been in place in the gutenberg plugin.
The idea is that this makes the editor match the frontend by default for these themes.
If they use a custom font, they'll have to provide it for the editor as editor styles.

Props nosolosw.


git-svn-id: https://develop.svn.wordpress.org/trunk@51240 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-includes/block-editor.php

@@ -470,12 +470,17 @@ function block_editor_rest_api_preload( array $preload_paths, $block_editor_cont
 function get_block_editor_theme_styles() {
 	global $editor_styles;
 
-	$styles = array(
-		array(
-			'css'            => 'body { font-family: -apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Oxygen-Sans,Ubuntu,Cantarell,"Helvetica Neue",sans-serif }',
-			'__unstableType' => 'core',
-		),
-	);
+	if ( ! WP_Theme_JSON_Resolver::theme_has_support() ) {
+		$styles = array(
+			array(
+				'css'            => 'body { font-family: -apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Oxygen-Sans,Ubuntu,Cantarell,"Helvetica Neue",sans-serif }',
+				'__unstableType' => 'core',
+			),
+		);
+	} else {
+		$styles = array();
+	}
+
 	if ( $editor_styles && current_theme_supports( 'editor-styles' ) ) {
 		foreach ( $editor_styles as $style ) {
 			if ( preg_match( '~^(https?:)?//~', $style ) ) {