Export fails if field missing in them.json

Hey!

Today I tried to export a custom child theme including the fonts from the site editor and run into the following warnings and errors:

[12-May-2024 14:21:46 UTC] PHP Warning:  Undefined array key "typography" in /wp-content/plugins/create-block-theme/admin/create-theme/theme-fonts.php on line 111
[12-May-2024 14:21:46 UTC] PHP Warning:  Trying to access array offset on null in /wp-content/plugins/create-block-theme/admin/create-theme/theme-fonts.php on line 111
[12-May-2024 14:21:46 UTC] PHP Fatal error:  Uncaught TypeError: array_filter(): Argument #1 ($array) must be of type array, null given in /wp-content/plugins/create-block-theme/admin/create-theme/theme-fonts.php:110
Stack trace:
#0 /wp-content/plugins/create-block-theme/admin/create-theme/theme-fonts.php(110): array_filter(NULL, Object(Closure))
#1 /wp-content/plugins/create-block-theme/admin/create-theme/theme-fonts.php(11): Theme_Fonts::remove_deactivated_fonts_from_theme()
#2 /wp-content/plugins/create-block-theme/includes/class-create-block-theme-api.php(444): Theme_Fonts::persist_font_settings()
#3 /wp-includes/rest-api/class-wp-rest-server.php(1230): Create_Block_Theme_API->rest_save_theme(Object(WP_REST_Request))
#4 /wp-includes/rest-api/class-wp-rest-server.php(1063): WP_REST_Server->respond_to_request(Object(WP_REST_Request), '/create-block-t...', Array, NULL)
#5 /wp-includes/rest-api/class-wp-rest-server.php(439): WP_REST_Server->dispatch(Object(WP_REST_Request))
#6 /wp-includes/rest-api.php(428): WP_REST_Server->serve_request('/create-block-t...')
#7 /wp-includes/class-wp-hook.php(324): rest_api_loaded(Object(WP))
#8 /wp-includes/class-wp-hook.php(348): WP_Hook->apply_filters(NULL, Array)
#9 /wp-includes/plugin.php(565): WP_Hook->do_action(Array)
#10 /wp-includes/class-wp.php(418): do_action_ref_array('parse_request', Array)
#11 /wp-includes/class-wp.php(813): WP->parse_request('')
#12 /wp-includes/functions.php(1336): WP->main('')
#13 /wp-blog-header.php(16): wp()
#14 /index.php(17): require('/Users/mrx')
#15 {main}
  thrown in /wp-content/plugins/create-block-theme/admin/create-theme/theme-fonts.php on line 110

The custom theme.json doesn’t have a typography field inside the settings array.

As soon as I add the following array to the theme.json file the export works fine:

"typography": {
	"fontFamilies": []
}

Greetings
derRALF