[wp-trac] [WordPress Trac] #55330: Set global_styles_svg_filters transient to return true causing symbol `1` to be appeared on the screen in a production mode

[WordPress Trac]

#55330: Set global_styles_svg_filters transient to return true causing symbol `1`
to be appeared on the screen in a production mode
------------------------------+-----------------------------
 Reporter:  aliakseyenkaihar  |      Owner:  (none)
     Type:  enhancement       |     Status:  new
 Priority:  normal            |  Milestone:  Awaiting Review
Component:  General           |    Version:  5.9.1
 Severity:  trivial           |   Keywords:
  Focuses:                    |
------------------------------+-----------------------------
 WordPress 5.9.1
 PHP 8.0.15

 When I set `global_styles_svg_filters` to return true (to prevent from
 being set - I don't use `theme.json` but request is sending so I want to
 disable it) it renders `1` at the top of the website

 Steps to reproduce on TwentyTwentyTwo theme:

 1. Paste these lines in `functions.php`

 {{{#!php
 <?php
 // @see https://github.com/WordPress/WordPress/blob/master/wp-
 includes/option.php#L131
 $theme = get_stylesheet();
 add_filter( "pre_transient_global_styles_svg_filters_{$theme}",
 '__return_true' );
 }}}

 You will see `1` at the top of any screen on site's front

 If you define `WP_DEBUG` as `true` or `WP_ENVIRONMENT_TYPE` as
 `development` it will dissapear

 It happens [here](https://github.com/WordPress/WordPress/blob/master/wp-
 includes/script-loader.php#L2361) - `wp_get_global_styles_svg_filters()`
 function will return `true` (as I manually set transient) so `$cached`
 [will](https://github.com/WordPress/WordPress/blob/2399966d8ce0f89e3989360929fa01edf86e15c0
 /wp-includes/global-styles-and-settings.php#L172) be `true` as well.
 Therefore it echoing as 1

 It is so minor and specific but it happened to me :) So because I may set
 any return type for this transient my guess there is no need for extra
 check but for a filter. For example

 {{{#!php
 <?php
 // script-loader.php
 $svg_filters = wp_get_global_styles_svg_filters();
 $filters = apply_filters( 'wp_get_global_styles_svg_filters', $svg_filters
 );
 }}}

 This way I will control svg filters output myself

-- 
Ticket URL: <https://core.trac.wordpress.org/ticket/55330>
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