Add a databse persisted fallback for the default font folder path

src/wp-includes/fonts.php

@@ -92,22 +92,20 @@ function wp_unregister_font_collection( string $slug ) {
 }
 
 /**
- * Returns an array containing the current fonts upload directory's path and URL.
+ * Returns the default font directory path and URL.
  *
  * @since 6.5.0
  *
- * @return array $defaults {
- *     Array of information about the upload directory.
- *
- *     @type string       $path    Base directory and subdirectory or full path to the fonts upload directory.
- *     @type string       $url     Base URL and subdirectory or absolute URL to the fonts upload directory.
- *     @type string       $subdir  Subdirectory
- *     @type string       $basedir Path without subdir.
- *     @type string       $baseurl URL path without subdir.
- *     @type string|false $error   False or error message.
- * }
+ * @param bool $refresh_cache Optional. Whether to refresh the cache and generate a new default font directory path and URL. Default is false.
+ * @return array Default font directory path and URL.
  */
-function wp_get_font_dir() {
+function wp_default_font_dir( $refresh_cache = false ) {
+	$defaults = get_option( 'font_dir' );
+
+	if ( ! empty( $defaults ) && ! $refresh_cache ) {
+		return $defaults;
+	}
+
 	$site_path = '';
 	if ( is_multisite() && ! ( is_main_network() && is_main_site() ) ) {
 		$site_path = '/sites/' . get_current_blog_id();
@@ -122,6 +120,40 @@ function wp_get_font_dir() {
 		'error'   => false,
 	);
 
+	wp_mkdir_p( $defaults['path'] );
+
+	if ( ! wp_is_writable( $defaults['path'] ) ) {
+		$defaults            = wp_upload_dir();
+		$defaults['path']    = path_join( $defaults['basedir'], 'fonts' );
+		$defaults['url']     = $defaults['baseurl'] . '/fonts';
+		$defaults['subdir']  = '';
+		$defaults['basedir'] = path_join( $defaults['basedir'], 'fonts' );
+		$defaults['baseurl'] = $defaults['baseurl'] . '/fonts';
+	}
+
+	update_option( 'font_dir', $defaults );
+	return $defaults;
+}
+
+/**
+ * Returns an array containing the current fonts upload directory's path and URL.
+ *
+ * @since 6.5.0
+ *
+ * @return array $defaults {
+ *     Array of information about the upload directory.
+ *
+ *     @type string       $path    Base directory and subdirectory or full path to the fonts upload directory.
+ *     @type string       $url     Base URL and subdirectory or absolute URL to the fonts upload directory.
+ *     @type string       $subdir  Subdirectory
+ *     @type string       $basedir Path without subdir.
+ *     @type string       $baseurl URL path without subdir.
+ *     @type string|false $error   False or error message.
+ * }
+ */
+function wp_get_font_dir() {
+	$defaults = wp_default_font_dir( true );
+
 	/**
 	 * Filters the fonts directory data.
 	 *

tests/phpunit/tests/fonts/wpDefaultFontDir.php

@@ -0,0 +1,51 @@
+<?php
+/**
+ * Test wp_default_font_dir().
+ *
+ * @package WordPress
+ * @subpackage Font Library
+ *
+ * @group fonts
+ * @group font-library
+ *
+ * @covers ::wp_default_font_dir
+ */
+class Tests_Fonts_WpDefaultFontDir extends WP_UnitTestCase {
+
+	public function test_default_font_dir() {
+		$font_dir = wp_default_font_dir();
+
+		$this->assertSame(
+			array(
+				'path'    => WP_CONTENT_DIR . '/fonts',
+				'url'     => content_url( 'fonts' ),
+				'subdir'  => '',
+				'basedir' => WP_CONTENT_DIR . '/fonts',
+				'baseurl' => content_url( 'fonts' ),
+				'error'   => false,
+			),
+			$font_dir,
+			'The font directory should be a dir inside wp-content'
+		);
+	}
+
+	public function test_uploads_font_dir() {
+		$font_dir = wp_default_font_dir( true );
+		chmod( $font_dir['path'], 0000 );
+
+		$upload_dir = wp_upload_dir();
+
+		$this->assertSame(
+			array(
+				'path'    => path_join( $upload_dir['basedir'], 'fonts' ),
+				'url'     => $upload_dir['baseurl'] . '/fonts',
+				'subdir'  => '',
+				'basedir' => path_join( $upload_dir['basedir'], 'fonts' ),
+				'baseurl' => $upload_dir['baseurl'] . '/fonts',
+				'error'   => false,
+			),
+			$font_dir,
+			'The font directory should be a subdir in the uploads directory.'
+		);
+	}
+}